DK THE ECOLOGY BOOK

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS 49

ECOLOGICAL PROCESSES

as antelopes and deer—and
mammalian carnivores, like the
big cats and wolves, is an example
of this evolutionary arms race. The
hoofed animals have long legs,
extended by walking on the very
tips of thickened and fused toe
bones. This adaptation allows
them to outrun and outjump their
predators. In response, big cats—
such as lions and tigers—have
evolved speed and strength to
bring down large, fleet-footed prey
in surprise attacks. Wolves have
evolved the stamina to run for
long distances without stopping.
This allows them to work as a
team to chase down their prey
and kill them when the exhausted
prey collapse.

While the predator–prey
equations offer an insight into
the population dynamics of two
species, the assumptions they rely
on are rarely reflected in real life.
Some predators do specialize in
killing a single prey species, but
other factors in the ecosystem
also affect their populations.

Other applications another species but also the prey The parasitoid wasp lays its eggs
The Lotka–Volterra equations have species of a third. They have in aphids (the smaller, yellow insects
been used to study the dynamics of also been used to examine the shown above). It is called a parasitoid
food chains and food webs in which relationship between host and because the wasp’s larvae later eat the
one species may be a predator of parasite species, which bears aphids as they grow.
some resemblance to that between
Volterra was interested prey and predator. Parasites often thanks to beneficial genes, certain
in a mathematical specialize in one host species— individuals in a host population
a relationship that should resemble are able to maintain their fitness
theory of ‘the survival the one described by the Lotka– despite the attacks from parasites.
of the fittest.’ Volterra equations. However, in The parasites constantly evolve to
practice the process of evolution exploit these seemingly immune
Alexander Weinstein is thought to interfere with this. individuals, and therefore the
A parasite does not usually kill beneficial genes in the host
Russian mathematician its host (those that do are called population also change. In this way,
parasitoids), but can reduce its evolution is happening all the time,
fitness. The Red Queen evolutionary as the parasite and host battle it
theory, proposed in the 1970s by out—although everything appears
Leigh Van Valen, describes how, to stay the same. ■

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

50

OBEXYFIACSITSRELCNEUCNMEDSEISTRADTNEHCTREEESRAMDINED

ECOLOGICAL NICHES

IN CONTEXT A n organism’s niche is competition with other species.
a combination of its For ecologists, a full knowledge
KEY FIGURE place and its role in the of an organism’s niche is vital to
Joseph Grinnell (1877–1939) environment. It encompasses how inform interventions to compensate
the organism meets its needs for for the environmental changes
BEFORE food and shelter, as well as how it caused by habitat destruction and
1910 In a paper about beetles, avoids predators, competes with climate change.
Roswell Hill Johnson, a US other species, and reproduces.
biologist, is the first person All its interactions with other The pioneer of the niche
to use the word “niche” in organisms and the nonliving concept was Joseph Grinnell, a US
a biological context. environment are also part of what biologist who studied a bird called
makes up its niche. A unique niche the California Thrasher. In 1917, he
AFTER is an advantage for any animal or published his observations, which
1927 British ecologist Charles plant because this reduces showed how the bird fed and bred
Elton stresses the importance in the underbrush of a scrubby
of an organism’s role as well as
its “address” in his definition of There is constant Reducing competition
an ecological niche in his book competition for food and increases the chances
Animal Ecology. resources; better adapted
species outcompete those of survival.
1957 In an academic paper
called “Concluding Remarks,” less suited to the
British ecologist George environment.
Evelyn Hutchinson expands
the theory of niches to Existence of each Finding a unique niche
embrace an organism’s entire species is is the circumstance that
environment.
determined by a removes competition.
1968 A study by Australian slender thread
D.R. Klein of the introduction, of circumstances.
increase, and die-off of reindeer
on St. Matthew Island, Alaska,
identifies the destructive niche.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS 51

ECOLOGICAL PROCESSES

See also: Competitive exclusion principle 52–53 ■ Field experiments 54–55 ■ Optimal foraging theory 66–67
■ Animal ecology 106–113 ■ Niche construction 188–189

An ultra-specialist Giant pandas occupy a very Pandas eat different parts of
specialized ecological niche, as bamboo plants according to the
their diet consists mainly of seasons. In late spring, they
bamboo. Bamboo is a poor food prefer the first green shoots.
source, low in protein and high in They eat leaves at other times
cellulose. Pandas can digest only of the year, and stems in winter
a small proportion of what they when little else is available.
eat, which means they have to Pandas have evolved muscular
eat a lot of bamboo—as much as jaws and a pseudothumb to
28 lb (12.5 kg) each day—and manipulate bamboo stems. Their
forage for up to 14 hours a day. digestive tract is inefficient at
It is unclear why pandas have processing large quantities of
become so dependent on bamboo, plant material because it
but some zoologists suggest it is remains similar to that of its
because it is an abundant and carnivorous ancestors, although
reliable food source, and pandas digestion is helped by the
are not skilled predators. bacterial fauna in their gut.

habitat known as chaparral, and factors. Thirty years later, George coexist (niche partitioning), and
how it escaped predators by Evelyn Hutchinson expanded the the overlap of resources by different
running through the underbrush. definition yet further. He argued animals and plants (niche overlap).
The thrasher’s camouflage, short that a niche should take into
wings, and strong legs were account all of an organism’s The importance of habitat
perfectly adapted for life in this interactions with other organisms Ecological niches depend on the
environment. Grinnell saw the and its nonliving environment, existence of a stable habitat; small
chaparral habitat as the thrasher’s including geology, acidity of soil or changes can eradicate niches that
“niche.” His idea also allowed for water, nutrient flows, and climate. organisms once filled. For example,
“ecological equivalence” in plants Hutchinson’s work encouraged dragonfly larvae only develop
and animals, whereby species others to explain the variety of within a certain range of water
distantly related and living far resources used by a single acidity, chemical composition,
apart could show similar organism (niche breadth), the ways temperature, and prey, and with
adaptations, such as feeding in which competing species a limited number of predators.
habits, in similar niches. In the The right vegetation is needed by
Australian outback, for instance, [A niche] is a highly adult females for egg-laying, and
babbler bird species forage in the abstract multi- by larvae for metamorphosis.
scrubby vegetation in a similar way The dragonfly also impacts its
to the unrelated thrasher. Grinnell dimensional hyperspace. environment: its eggs are food for
also identified “vacant” niches— George Evelyn amphibians; its larvae, which are
habitats that a species could Hutchinson both predators and prey, add
potentially occupy, but where it nutrients to the water; and the
was not present. adults prey on insects. These
requirements and impacts define
Widening the niche its ecological niche. Hutchinson
In the 1920s, ecologist Charles argued that for a species to persist,
Elton looked beyond a simple conditions had to be within the
habitat definition for “niche.” For required ranges. If conditions moved
him, what an animal ate and what outside the niche requirements, a
it was eaten by were the primary species could face extinction. ■

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

52

CCCOOANMMNPPOELTETITCTEOOERXSIST

COMPETITIVE EXCLUSION PRINCIPLE

IN CONTEXT C ompetition is the driver of adapts, so that it no longer
evolution; the need to be competes. This proposition, known
KEY FIGURE bigger, stronger, and better as the “competitive exclusion
Georgy Gause (1910–86) inevitably leads to adaptations that principle,” was set out by Russian
give a species an edge. When two microbiologist Georgy Gause and
BEFORE species compete for identical is also known as Gause’s Law.
1925 Alfred James Lotka first resources, the one which has any
uses equations to analyze advantage will outdo the other. As Gause devised his principle
variations in predator–prey a result, the weaker of the two from laboratory experiments, using
populations, as does species either becomes extinct or cultures of microorganisms, rather
mathematician Vito Volterra, than from observations in nature. In
independently, a year later.
How warblers coexist
1927 Volterra enlarges and
updates his 1926 study to Cape May Blackburnian Black-throated
include various ecological Warbler Warbler Green Warbler
interactions within
communities. Five species of
warblers are able to
AFTER share the same tree,
1959 G. Evelyn Hutchinson because each inhabits
extends Gause’s ideas and its own “niche.” Living
produces a ratio describing the in this way, without
limit of similarity between two much overlap, the
competing species. birds do not compete.

1967 Robert MacArthur and
Richard Levins use probability
theory and Lotka–Volterra
equations to describe how
coexisting species interact.

Bay-breasted Yellow-rumped
Warbler Warbler

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

ECOLOGICAL PROCESSES 53

See also: Evolution by natural selection 24–31 ■ Ecological niches 50–51 ■ Animal ecology 106–113 ■ The ecosystem
134–137 ■ The ecological guild 176–177 ■ Niche construction 188–189 ■ Invasive species 270–273

The red squirrel is smaller than the genetics. In fact, the competitive Let us make for this purpose
gray, and has a more restricted diet exclusion principle—although a an artificial microcosm… let
and habitat. Reds may also die from the useful theoretical model—is rarely us fill a test-tube with nutritive
squirrel parapoxvirus, which is carried seen in nature, simply because, in a medium and introduce to it
by the grays but does not affect them. bid to survive, a weaker competitor several species of protozoa
tends to quickly move on or adapt. consuming the same food
nature, he proposed, there were too
many variables to draw conclusions Avoiding competition or devouring each other.
about how ecological mechanisms Most creatures can make the Georgy Gause
work. He argued that little progress changes necessary for survival. A
had been made since Darwin’s era variety of birds can live in a garden at different heights and depths of
in understanding how species during any one year because they the foliage. In this way they avoid
compete for survival, whereas the all operate in different “niches.” competing with each other.
experimental method had produced They have contrasting beak shapes
great advances in areas such as and sizes that allow them to eat An invasive competitor
different types of food—the robin Problems often arise if an exotic
Types of competition preferring insects, the finch eating species is suddenly introduced
seeds. Their choice of habitat and to an ecosystem. Britain’s red
The Competitive Exclusion feeding times might also vary; this and gray squirrels provide a clear
Principle covers two main types is known as resource partitioning. example. When the grey arrived
of competition. Intraspecific from America in the 1870s, both
competition is between In 1957, Robert MacArthur squirrel species competed for the
individuals of the same species noted this phenomenon in North same food and habitat, which put
and ensures the survival of American warblers. The five the native red squirrel populations
the fittest, so that only the species he observed, each with under pressure. The gray had
healthiest individuals—or those distinctive, colorful markings, the edge because it can adapt
best adapted to a particular flitted in and out of coniferous its diet; it is able, for instance, to
environment—will breed. The trees, feeding on bugs and other eat green acorns, while the red can
second type is interspecific: insects. They could coexist in one only digest mature acorns. Within
competition between two habitat because they did not try to the same area of forest, gray
different species that rely on feed in the same part of the tree but squirrels can decimate the food
the same resources. The most supply before red squirrels even
important of these will be the “limiting resource,” the one that have a nibble. Grays can also live
both require in order to breed. more densely and in varied
Ecologists make a further two habitats, so have survived more
distinctions. Interference is easily when woodland has been
when two organisms fight destroyed. As a result, the red
directly with each other over a squirrel has come close to
limited resource, such as a mate extinction in England. ■
or a preferred food. Exploitation
is indirect competiton, such as
stripping out a resource so there
is none left for the competitor;
this can be seen in plants, when
a species’ uptake of nutrients or
water is more efficient than that
of its neighbors.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

54

PECTOXHAPONAENRBRUFEIMISWEEELONLDERTSSSSE

FIELD EXPERIMENTS

IN CONTEXT E xperimentation is crucial have been recognized. Before
in ecology. Without it, our the 1960s, experiments outside
KEY FIGURE ideas about why organisms a laboratory were a rarity.
Joseph Connell (1923–) behave the way they do would be
largely speculative. Rigorous A laboratory, however, is an
BEFORE observation is also essential, but, artificial environment, where
1856 British scientists John much of the time, experimentation organisms may not behave as they
Lawes and Joseph Gilbert start is needed for a full understanding do in their natural habitat. For
the Park Grass Experiment at of those observations. example, bats leaving a roost at
Rothamsted, to test how dusk may follow different routes
different fertilizers affect the Three main types of ecological to their foraging areas in spring
yield of hay meadows. experiments are used to test and late summer. The potential
theories: mathematical models, reasons for the switch—changes
1938 Harry Hatton, a French laboratory experiments, and field in prey distribution and predator
ecologist, conducts one of experiments. Each method has its threats; seasonal differences in
the first marine ecology field merits, but it is only recently that tree cover; or human disturbance
experiments, on barnacles the benefits of field experiments and light pollution—cannot
on the Brittany coast. be established in a laboratory.
Mathematical modeling might help
AFTER predict patterns, but would be less
1966 American ecologist effective at identifying the causes
Robert Paine removes the of change. To understand the bats’
starfish Pisaster ochraceus from behavior, a study of their natural
tide pools in a Pacific coast environment is crucial, and
ecosystem, to test the effect this is achieved only through
of its absence on other species. research in the field.

1968 The Experimental Lakes Field experiments allow different
Area, comprising 58 freshwater factors to be manipulated to test
lakes, is established in Ontario, their relevance. In the bat example,
Canada, to study the effects
of nutrient enrichment Rain forest ecosystems are some of
(eutrophication). the most species-rich environments
on Earth. This makes them especially
valuable sites for ecologists to conduct
experiments in the field.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

ECOLOGICAL PROCESSES 55

See also: Ecological niches 50–51 ■ Modern view of diversity 90–91 ■ Animal behavior 116–117 ■ The ecosystem 134–137
■ Niche construction 188–189

street lights could be switched off to Joseph Connell’s barnacle experiment
evaluate the impact of light pollution
on their behavior change. Chthamalus Highly desiccated
Balanus area during low tide
Scottish barnacles
In 1961, American ecologist Joseph High tide
Connell published the results of
his research on barnacles on the This experiment showed Fundamental
Scottish coast. Since free-swimming that Balanus could live only niches
barnacle larvae can settle anywhere, in the lower intertidal zone, Realized
Connell had tested why the lower while Chthamalus could live niches
part of the intertidal zone was
colonized by Balanus balanoides in both the upper and lower
barnacles and the upper part by zones, but was outcompeted
Chthamalus stellatus. He wanted to by Balanus in the lower zone.
know if this was due to competition,
predation, or environmental factors. Ocean

Connell manipulated the local Low tide
environment, and monitored it for
over a year. In one area, he removed species could live in the lower zone, successful when their nearest
the Chthamalus barnacles. They but only one could survive higher neighbor was of the same species.
were not replaced by Balanus, up. This suggested that Chthamalus Each species is targeted by specific
which suggested that Balanus could was better able to deal with the herbivores and pathogens, which
not tolerate the desiccation that harsh conditions of the upper zone, will also eat or attack smaller,
occurred in the upper zone at low but was outcompeted by Balanus weaker individuals of the species
tide. Connell then removed the lower down. The “fundamental nearby. This prevents “clumping”
Balanus population from the lower niche” of Chthamalus (where the of one tree species.
zone, and found that Chthamalus species would normally be able to
barnacles did replace them. Both survive) encompassed both zones, In 1978, Connell proposed
but its “realized niche” (the actual the intermediate disturbance
[Connell’s] studies … have area it inhabits) was more restricted. hypothesis (IDH). This states
improved our understanding that both high and low levels of
Diversity experiments disturbance reduce species
of the mechanisms In the early 1970s, Connell and diversity in an ecosystem, so the
that shape population American ecologist Daniel Janzen greatest range of species can be
published an explanation of the expected between those extremes.
and community degree of tree diversity in tropical Several studies support IDH. One,
dynamics, diversity, forests: the Janzen–Connell carried out in waters off Western
hypothesis. Connell mapped Australia, examined the effects of
and demography. trees in two rain forests in North wave disturbance on diversity.
Stephen Schroeter Queensland, Australia, and found Species diversity was found to be
that seedlings tended to be less low both at exposed offshore sites
Marine scientist and at sheltered sites. ■

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

56

MMMANEEODAARNNEMSMNOMEROCEORTREAAENNRTAESCNTTASR IN CONTEXT

MUTUALISMS KEY FIGURE
Dan Janzen (1939–)

BEFORE
1862 Charles Darwin proposes
that an African orchid with
a long nectar receptacle must
be pollinated by a moth with
an equally long proboscis.

1873 Belgian zoologist Pierre-
Joseph van Beneden first
uses the term “mutualism”
in a biological context.

1964 The term “coevolution”
is first used by American
biologists Paul Ehrlich and
Peter Raven to describe
the mutualistic relations
between butterflies and
their food plants.

AFTER
2014 Researchers discover
an unusual yet beneficial
three-way mutualism involving
sloths, algae, and moths.

I n biology, there are several
kinds of interaction between
organisms. One species in an
ecosystem may lose out to another
when competing for the same
resources. A prey species may be
eaten by a predator. There are also
symbiotic relationships, in which
one species benefits but not at the
expense of the other, or where one
organism does not benefit but still
survives. In the relationship known
as “mutualism,” both organisms
benefit from the relationship.

A tree and its ants
In the mid-1960s, Daniel Janzen,
a young American ecologist,
became fascinated by the amazing

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

ECOLOGICAL PROCESSES 57

See also: Evolution by natural selection 24–31 ■ Ecological niches 50–51 Yuccas and
■ Competitive exclusion principle 52–53 ■ Animal ecology 106–113 their moths

mutualistic relationship between Ants and their larvae shelter inside In the hot, arid regions
acacia trees and ants in eastern the swollen thorn of an East African of the Americas, there is
Mexico. His research was one of whistling thorn acacia tree. In return a remarkable mutualistic
the first in-depth studies of such the ants swarm from their nests relationship between yucca
an interaction. The two partners to protect the tree from herbivores. shrubs and yucca moths. No
were the swollen-thorn acacia and other insects pollinate these
the acacia ant, which lives in the Without the ants, a tree would be plants, and no other plants
bullhorn-shaped thorns of the tree. stripped of its leaves and die within host yucca moth caterpillars.
He found that queen ants sought six months or a year. Because it A female yucca moth collects
out unoccupied shoots, cut a hole could not sustain growth, it was pollen from the flower of one
in one of the swollen thorns, and also likely to be shaded out by yucca plant and deposits it in
laid their eggs, sometimes leaving competing trees. Janzen clipped the flower of another yucca,
the thorn to forage on the tree’s thorns and cut or burned shoots fertilizing the plant as it does
nectar. Larvae hatching from the to remove ants from trees, and so. The moth then cuts a hole
eggs then fed on the acacia’s leaf- found that the ants moved back in in the flower’s ovary and lays
tips, with their rich supplies of when new thorns started to grow. an egg; she may lay several
sugars and proteins. The larvae in the same flower. When the
later metamorphosed into worker In return for food and shelter, eggs hatch, the caterpillars
ants. In time, all the tree’s thorns the ants provided two services feed on the seeds developing
became occupied, with up to for the tree: they defended its in the flower but do not eat
30,000 ants living in a colony. foliage from leaf-eating insects them all, leaving enough for
and ate potentially competitive tree the plant to propagate. If too
Janzen showed that, unless the seedlings growingclose by. Janzen many eggs are laid in one
acacia ants were present to defend described the acacias and their flower, the plant sheds it
it, the swollen-thorn acacia lost ants as “obligate mutualists”, before the caterpillars hatch –
the ability to withstand damage meaning that one species would leaving those insects to
caused by insects that ate its die out without the other. If the ants starve. Without these moths,
leaves, stems, flowers, and roots. were removed, the swollen-thorn ❯❯ the yuccas would not pollinate
and would soon die out.
Without the yuccas, the moths
would have nowhere to lay
and nurture their eggs, and
they too would not survive.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

58 MUTUALISMS

1. Adult female wasp There is
mutual aid
Life cycle of the in many species.
fig wasp Pierre-Joseph
van Beneden

Belgian zoologist

2. Wasp enters fig, 4 . New-generation
lays eggs, pollinates adult female wasps
pick up pollen and
flowers, and dies
emerge from fig

3. Inside mature fig, and thence disperse their spores.
male wasps fertilize When a bird swallows a fruit, it
new females and dig carries the seeds with it
escape tunnels for them as it flies away; the indigestible
The fig wasp and the fig share a complex seeds may be excreted in faeces
service-resource mutualism, in which the wasp provides far from where they were eaten.
the service of pollination and the fig plants provide In all these situations, the plants
a secure environment for the wasp eggs to develop. provide a resource (food) and the
mammals, flies, and birds provide
acacia would have no means of the animal. It is estimated that a service (transport).
defending itself. And if the acacia nearly three-quarters of flowering
trees were removed, the ants would plants (some 170,000 species) are However, not all mutualistic
have no home. pollinated by 200,000 animal relationships involve plants. In
species. Typically, a pollinating Africa, birds named oxpeckers
Benefits for all insect is attracted to a flower by its and herbivorous mammals such
There are two fundamental types colours or scent to drink nectar or as impalas and zebras practise
of mutualism—service-resource collect pollen, and pollen attaches another kind of service-resource
and service-service relationships. to part of the insect’s body to be mutualism. The oxpeckers pick
They are defined by the nature carried to the next flower, where ticks from the mammals’ fur,
of the relationship between the it is deposited. The flower and its removing irritation and a source
partner organisms, whether it is pollinator have evolved to make of disease, while at the same time
the provision of a service or the this mechanism work effectively. having a meal. Oxpeckers also
supply of a resource—both are make loud calls when they sense
usually key to survival. Service- Some plants have also evolved danger, alerting the mammal host
resource relationships are common a service-resource relationship in as well as other oxpeckers.
in nature, with the fertilization, or which birds and mammals disperse
pollination, of flowers by butterflies, their seeds, spores, or fruit. Seeds In the insect world, some ants
moths, bees, flies, wasps, beetles, may become attached to the fur of and aphids carry out a different
bats, or birds the most widespread a mammal browsing the plant’s form of service-resource mutualism.
example. The resource (pollen) is leaves; when the mammal wanders While the aphids feed on plants,
provided by the flower, and the away, it disperses the seed. The the ants protect the aphids.
service (pollination) is provided by vile odor of stinkhorn fungi attracts Subsequently, the ants consume
flies, which lick the fungi’s slime the honeydew that the aphids
release, using a “milking” process
on their smaller partners, by
stroking them with their antennae.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS 59

ECOLOGICAL PROCESSES

Service-service mutualisms, in return for the protection offered of orchids. Like many other
which both organisms offer each by the sea anemones’ venomous flowering plants, orchids rely on
other protection, are far less tentacles, the clownfish deters insects to pollinate them. Some
common. One unusual relationship predatory butterfly fish, removes have extraordinary structures in
takes place in the western Pacific parasites from its host, and also which to hold nectar and pollen.
Ocean, between around 30 species provides nutrients from its faeces. To lure the insect pollinators, the
of clownfish and 10 species of plants offer them a drink of energy-
venomous sea anemones. The sea Cooperative evolution giving nectar. This fascinated
anemones’ stinging, toxin-filled Relationships between service and Darwin, who was given a specimen
nematocysts, or capsules, on their resource providers have developed of the Madagascar orchid in 1862.
tentacles kill most small fish that over millions of years in a process The flower stores its nectar in a
come close, but not the clownfish. called “coevolution”—the evolution hollow spur nearly 30 cm (12 in)
Its thick layer of protective mucus of two or more species that affect long. Darwin and Wallace
provides immunity against the each other reciprocally. speculated that only a large moth
anemone’s sting, allowing the fish could have a proboscis long enough
to live within the tentacles. In The term coevolution was to reach the nectar—a theory
coined by American biologists Paul eventually proven in 1997. If the
The clownfish and sea anemone Ehrlich and Peter Raven in 1964, orchid’s spur were shorter, a moth
could both survive without the other’s but a century before the word could drink without picking up
protection, but their coevolved mutual existed, the naturalists Charles pollen and so would not pollinate
relationship gives them a much higher Darwin and Alfred Russel Wallace the flower. If the spur were longer,
chance of survival. were already aware of the concept, a moth would not visit. ■
not least through their observation

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

WHELKS

WOLVESARE LIKE LITTLE

IN SLOW MOTION

KEYSTONE SPECIES

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

62 KEYSTONE SPECIES

IN CONTEXT A keystone species plays Do you want an auto
a crucial role in the way mechanic who…can name,
KEY FIGURE an ecosystem functions, list, and count all of the parts
Robert Paine (1933–2016) even though it is often a small of your engine, or one who
part of the overall biomass of the really understands how each
BEFORE ecosystem. Because it exerts a part interacts with the others
1950s In Kenya, farmer and disproportionately large effect on to make a working engine?
conservationist David the environment relative to its
Sheldrick introduces elephants biomass, if a keystone species Robert Paine
to Tsavo East National Park, disappears from an ecosystem,
and discovers this results in a that ecosystem will change clear impact on many others. Paine
major increase in biodiversity. dramatically. The importance of developed the idea to include the
keystone species was brought to concept of “trophic cascades”—the
1961 Fieldwork by American light by the American biologist strong, top-down effects that ripple
ecologist Joseph Connell on Robert Paine—who derived the through an ecosystem and its
Scotland’s rocky shores shows term from the central “keystone” at organisms. Since Paine’s work
that removing predatory the top of an arch that stops it from with starfish, several studies
whelks alters the distribution collapsing—in his 1969 article “A have demonstrated that there are
of their barnacle prey. Note on Trophic Complexity and
Community Stability.” Black-tailed prairie dogs look
AFTER out from their burrow in a field in
1994 In the US, a group of The keystone concept Wyoming. Study of this species has
ecologists led by Brian Miller In the 1960s, Paine spent several revealed its key role in fostering
publishes a paper explaining years studying the animals of the diversity in its native habitat.
the valuable role prairie dogs intertidal zone of Tatoosh Island
play as a keystone species. on the Pacific coast of Washington
State. He removed the ocher
2016 Fieldwork leads marine starfish and watched its key prey,
ecologist Sarah Gravem to a mussel whose numbers had
conclude that organisms can been kept in check by the starfish,
be keystone species in some dominate the zone, replacing other
places but not in others. subordinate species. The removal
of a single, keystone species had a

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS 63

ECOLOGICAL PROCESSES

See also: Predator–prey equations 44–49 ■ Mutualisms 56–59 ■ Animal ecology
106–113 ■ Trophic cascades 140–143 ■ Evolutionarily stable state 154–155

Whelks feed on They also display
barnacles; they aggression toward
are predators.
their prey.

Whelks are like In areas where Robert Paine
little wolves in there are large
slow motion. concentrations Born in 1933, in Cambridge,
of barnacles, groups of Massachusetts, Robert Paine
whelks congregate— studied at Harvard. After a
like wolf packs. stint in the US Army, where
he was the battalion gardener,
many other keystone organisms, area to hunt for prey, and the ferrets Paine focused his research
and they each fulfill their role in and tiger salamanders use the on marine invertebrates.
different ways. burrows for shelter. Almost 150 His study of the relationship
species of plant and animal are between starfish and mussels
Ecological engineers known to benefit from prairie dog on the Paciic coast led him
Prairie dogs in the American colonies. Although there are to propose the concept
Midwest are a good example of a “losers”—notably vertebrates that of keystone species—the
keystone species whose impact is favor tall vegetation—the prairie disproportionate impact that
the result of their “engineering” dogs’ presence increases overall a single species can have on
activities. Huge colonies of these biodiversity. When colonies die out, its ecosystem.
small mammals dig networks of scrubby patches of mesquite
tunnels beneath the prairie vegetation replace short grasses, Paine worked for most of
grasslands. They sleep and raise plovers abandon the area, and his career at the University
their young in these extensive predator numbers decline. of Washington, where he
burrows, converting the grassland popularized field manipulation
into a suitable habitat. Coral cleaners experiments, or “kick-it-and-
The princess parrotfish in the see” ecology. He was awarded
The prairie dogs’ constant Caribbean is another keystone the International Cosmos
digging dramatically increases species, this time because of the Award by the National
soil turnover and allows nutrients consequences of its feeding. The Academy of Sciences in 2013,
and water from rain and snow to fish lives around coral reefs, where and died in 2016.
penetrate deeper than would corals fight each other for light,
otherwise be the case. The damp, nutrients, and space. The parrotfish Key works
nutrient-rich soil encourages a scrapes the surfaces of the corals to
diversity of plants, and birds such remove layers of algal seaweed to 1966 “Food Web Complexity
as Mountain Plovers feed and nest eat. If the parrotfish did not do this, and Species Diversity,”
in the short grass. Predators like clumps of seaweed would grow on American Naturalist
Ferruginous Hawks and black- the corals, smothering as well as ❯❯ 1969 “A Note on Trophic
footed ferrets are attracted to the Complexity and Community
Stability,” American Naturalist
1994 Marine Rocky Shores
and Community Ecology: An
Experimentalist’s Perspective

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

64 KEYSTONE SPECIES

chemically damaging the reef. If the destructive behavior helps undigested seeds pass through
parrotfish was overfished or died maintain the feeding habitat for their gut, are then defecated, and
out from disease, the health of the grazing animals such as zebras, later germinate. Up to one-third
reefs would rapidly deteriorate. antelope, and wildebeest. It also of all West African tree species
indirectly helps the predators that depend on elephants for their seed
Landscape managers hunt the grazers—including lions, dispersal. Elephants also dig and
On African grasslands, elephants cheetahs, and hyenas—and the maintain waterholes, which benefit
smash down small and medium- smaller mammals that burrow in many other species.
sized trees for food, helping grassland soils. Without the
maintain savanna as grassland elephants, these animals would Forest-dwelling Asian elephants
and opening up new areas that soon disappear. Elephants are also have a similar role. In southeast
were formerly woodland. This very important seed dispersers; Asia, they smash through gaps and
clearings in woodland, opening up
Yellowstone wolfpack territories holes in the canopy. The new plants
that grow in these unshaded areas
Cinnabar Junction add to the forest’s plant and animal
Butte diversity and also help a broader
8 Mile range of animals to thrive there.
Prospect
Peak Keystone predators
The sea otter is a marine mammal
Wapiti Lamar that lives in the Pacific coastal
Lake Canyon waters of North America. In the
18th and 19th centuries, they were
Cougar hunted extensively for their fur. By
the early 20th century, they had
Canyon Mollie’s been wiped out in many areas, and
their total population was thought
to be fewer than 2,000 individuals.
Since 1911, legal protection has led
to a slow increase in numbers.

Sea otters are important
because they eat large numbers
of sea urchins. These seafloor-
dwelling invertebrates graze on the
lower stems of kelp that grow up

Bechler Snake River Every species in the coastal
Each pack of wolves in the zone is influenced in one way
SCALE Yellowstone National Park has its own or another by the ecological
10km (6 miles) territory. Many of the territories overlap,
and numbers fluctuate from year to effects of sea otters.
year, with 108 wolves recorded in 2016. James Estes

American marine biologist

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS 65

ECOLOGICAL PROCESSES

Reintroducing Beavers were wiped out in the UK several dams on the headwaters
beavers to the UK 400 years ago, but the beneficial of the Tamar River, creating 13
role of this keystone mammal is new freshwater pools and making
now better understood. Beavers surrounding areas wetter.
are ecological engineers, building
dams and canals, and their In Devon, the damp areas
presence increases biodiversity. created by beavers led to an
increase in the number of
In 2009, 11 beavers were bryophyte species (mosses and
reintroduced to Knapdale Forest, liverworts), and the range of
Scotland, and in 2011, the Devon aquatic invertebrates has risen
Wildlife Trust introduced a pair to from 14 to 41 species. Increased
a fenced enclosure. Both projects numbers of flying insects have
have been monitored to test their also improved bat diversity, with
impact on the environment. In two nationally rare bat species
Knapdale Forest, the beavers’ drawn into the area. More
dams changed the water level of beaver reintroduction projects
a loch, and Devon’s beavers built are now planned in the UK.

from the seabed, causing it to drift herbivores, such as beavers. Within fruited plant species share one or
away and die. If the kelp disappears, 10 years, the number of beaver two peaks of ripening each year.
however, so do the many other colonies increased from one to nine. Fig trees bear fruit throughout the
marine invertebrates that graze on Beaver dams helped revive wetlands, year, supporting many animals
it. “Forests” of kelp also absorb large and wetland wildlife flourished. The when other trees are fruitless.
amounts of atmospheric carbon increase in elk carcasses also More than 10 percent of the world’s
dioxide and, by slowing water benefited carrion-eaters—especially bird species and 6 percent of
currents, help protect coastlines coyotes, red foxes, grizzly bears, mammals (a total of 1,274 species)
from storm surges. The protection Golden Eagles, Ravens, and Black- are known to eat figs, as do a small
that sea otters offer kelp along billed Magpies—as well as several number of reptiles and even fish.
stretches of open coast is therefore smaller scavengers. Fig trees therefore provide a vital
particularly significant. support mechanism for fruit-eating
Jaguars are apex predators in species. Without them, fruit bats,
Unlike the sea otter, some South and Central American forests, birds, and other creatures would
keystone species are also “apex” preying on more than 85 species. decline or disappear. ■
predators at the top of the food Although there are very few jaguars
chain, such as the gray wolf. Before in any given area, their impact on By protecting a keystone
1995, there had been no gray wolves the numbers of other predators— species such as the prairie
in Yellowstone National Park for at such as caimans, snakes, large
least 70 years. American elk were fish, and large birds—as well as dog, the public could be
common in the park, but there was herbivores, such as capybaras and educated about the value of
just a single colony of beavers. That deer, has a significant ripple-down
year, 31 wolves were introduced to effect on their ecosystem. Left ecosystem conservation.
the park and by 2001 their numbers unchecked, the herbivores could Brian Miller
had increased to more than 100, devour most of the plants and
largely due to the abundance of destroy the habitat on which so American ecologist
elk for food. many other species depend.

The presence of wolves in the Keystone plants
park forced the elk to become more Not all keystone species are
mobile. Rather than over-grazing animals. One example is the fig
willow, aspen, and cottonwood trees tree, of which there are about 750
in favored locations, the elk moved species, mostly found in tropical
on, allowing plants to regenerate forests. In this habitat, most fleshy-
and provide a food source for other

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

66

EDTAFHEFFPEOIECFRNIIAEDTGNNSICENOSYGNSAIOTNFSIMAL

OPTIMAL FORAGING THEORY

IN CONTEXT E very plant and animal helps predict the best strategy
on Earth needs resources that an animal can use to achieve
KEY FIGURES to survive. Plants obtain this goal.
Ronald Pulliam (1945–), their nutrients and water from soil,
Graham Pyke (1948–), and and sunlight provides the energy Foraging theories
Eric Charnov (1947–) for photosynthesis. Animals The first theory of foraging by
generally have to work harder to wild animals did not emerge until
BEFORE find their food—they have to move, the mid-1960s, when Americans
1966 John Merritt Emlen, and this uses extra resources. Robert MacArthur and Eric Pianka
Robert MacArthur, and Eric Optimal foraging theory (OFT) examined the question of why,
Pianka outline the concept proposes that animals try to gather when a range of food was available
of optimal foraging in two resources in the most efficient way to them, animals often restricted
articles published in the to avoid using additional energy. themselves to a few preferred types
American Naturalist magazine. Searching for and capturing food of prey. They argued that natural
takes energy and time. The animal selection favored animals whose
AFTER needs to gain maximum benefit behavior maximized their net
1984 Argentinian–British for minimal effort in order to energy intake per unit of time spent
zoologist Alejandro Kacelnik achieve optimal fitness. OFT foraging. An animal’s foraging time
researches the foraging includes searching for prey and the
behavior of starlings to Diets should be broad killing and eating of the food
illustrate the marginal when prey are scarce, (handling time).
value theorem (MVT).
but narrow if food These ideas were developed by
1986 Belgian ecologist Patrick is abundant. American ecologists Ronald Pulliam
Meire investigates prey Eric Pianka and Eric Charnov and Australian
selection by oystercatchers. ecologist Graham Pyke. It seems
that OFT works best for mobile
1989 Swiss environmental foragers seeking immobile prey, and
scientists T. J. Wolfe and Paul some researchers believe it is less
Schmid-Hempel examine how relevant when prey are mobile.
the weight of nectar carried
by bees has an effect on the Key choices
bees’ foraging behavior. Animals must choose which types
of food to eat, which is rarely
straightforward. For example,

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS 67

ECOLOGICAL PROCESSES

See also: Evolution by natural selection 24–31 ■ Predator–prey equations
44–49 ■ Competitive exclusion principle 52–53 ■ Mutualisms 56–59

The expected behavior of small clams was better spent Echolocating bats
animals with respect to digging for another, larger clam.
available resources can be A similar study with oystercatchers Technological advances have
used to predict … the biotic and mussels found that the largest greatly helped research into
structure … of communities. mussels were left—they had the hunting strategies of
thicker, barnacle-clad shells, so animals. Insectivorous bats
Ronald Pulliam opening them was more difficult. (also known as microbats)
The oystercatchers benefited more use echolocation in the
American ecologists Howard by looking for thin-shelled mussels, dark to locate and pursue
Richardson and Nicolaas Verbeek despite their smaller size. flying insect prey, such as
studied Northwestern Crows moths and midges. A team
feeding on clams in the intertidal Animals also have to make of Japanese scientists set out
zone of British Columbia. The choices about where and when to to study the bats’ feeding
crows put lots of effort into digging feed. The longer a starling spends behavior using microphone
clams out of the mud, opening the in one patch of suitable grassland, array measurements and
shells, and feeding on the animal for example, the harder it will mathematical modeling
inside. The ecologists noticed that become to find prey, so it has to analysis. The researchers
smaller clams went unopened and decide when to abandon that patch recorded the echolocation
concluded that the crows had to and move to another—an example calls and flight paths of the
make an energy trade-off between of what is known as the “marginal bats and discovered that they
handling time and edible food. The value theorem.” Foraging animals often directed their sonar not
time and energy needed to open up also need to consider a range of just at their immediate prey
other factors such as the presence but at the next target they
of predators, the number of animals were lining up as well.
competing for the same food, and
the impact of human activity. ■ The team also found
evidence that the bats chose
Oystercatchers, despite their name, flight paths that would allow
are reliant on cockles and mussels as them to plan two steps ahead,
their primary food source. Without rather like skilled chess
these shellfish, they are forced to players. Not only were the
forage farther inland. animals maximizing their
energy input by targeting
multiple prey items, but they
were also minimizing their
energy output by reducing
the distance they flew in
pursuit of insects. This
behavior fits in well with
optimal foraging theory.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

68

PPPPAAROTREPHDUAOSALTGIATOTEEINROSSSNACSNODLNIKTEROL IN CONTEXT

ECOLOGICAL EPIDEMIOLOGY KEY FIGURES
Roy Anderson (1947–),
Robert May (1936–)

BEFORE
1662 English statistician John
Graunt seeks to classify causes
of death in London in Natural
and Political Observations
made upon the Bills of Mortality.

1927 Scottish scientists
Anderson Gray McKendrick
and William Ogilvy Kermack
develop an epidemic model for
infected, uninfected, and
immune individuals.

AFTER
1996 American epidemiologist
James S. Koopman calls for
greater use of computational
technologies to simulate
disease generation and spread.

2018 A global team tracks the
origins and spread of a fungus
devastating frog populations.

E pidemiology is the study
of how disease spreads
through a population. Its
initial application was to human
diseases, but its methods have
been recognized as an effective
way of modeling populations of
other organisms, too.

Ecologists have long known
that the size of an animal or plant
population and its growth rate
depend on the availability of food,
living space, and levels of
predation. In the 1970s, British
epidemiologist Roy Anderson and
Australian scientist Robert May
showed how parasites and
infections from pathogens such as
bacteria and viruses limited the

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS 69

ECOLOGICAL PROCESSES

See also: The microbiological environment 84–85 ■ Microbiology 102–103 ■ The ubiquity of mycorrhizae 104–105
■ Biodiversity and ecosystem functioning 156–157

KEY Map of deaths from cholera in London in 1854 Soho
1–4 deaths Square
5–9 deaths Oxford Street

10–15 deaths Broad Street

Broad Street
pump

Fatalities in London’s Regent Street Brewer Street
cholera outbreak of
1854 were linked to the Golden
central pump; its water Square
was found to have
been contaminated
with infected sewage
from a stricken family.

size of a population. In wild sheep, thought to be caused by miasma—
for instance, the chief cause of a sort of poisonous vapor in the
death is lungworms, while most air—that spread from the bodies of
wild birds die from viral infections. the dead and dying. Snow was not
the first to question this theory, but
In ecology, the effects of disease he was especially suspicious of it in
have wider implications. Up to the case of cholera.
40 percent of ocean bacteria are
killed each day by viruses. This In 1854, Snow plotted every
causes a “viral shunt,” because case of cholera on a map of Soho,
nutrients that would otherwise flow and found that afflicted households
up the food chain to consumers collected their water from a pump
revert to the bottom of the chain. on Broad Street (later renamed
Broadwick). He shut down the ❯❯
Human beginnings
Epidemiology has its beginnings British doctor John Snow fought the
in the work of physician John Snow, establishment to gain acceptance for
who witnessed a cholera epidemic his belief that cholera was waterborne.
in the Soho district of London in The medical journal The Lancet finally
1854. At the time, disease was conceded that he was right in 1866.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

70 ECOLOGICAL EPIDEMIOLOGY

The role of drought pump, and the epidemic soon
in plant diseases ended. This showed that cholera
was a waterborne disease that
Like other disease-causing humans contracted through
agents, a plant pathogen contaminated food and drink. A
(disease-causing agent) decade later, Louis Pasteur’s “germ
needs a supply of susceptible theory” proposed that diseases, as
individuals to infect. Periods well as general rotting and decay,
of drought slow the rate of were the work of microorganisms.
plant reproduction and
growth, thereby reducing the Disease model A ravaged tree in North Yorkshire,
prevalence of disease. In their 1970s studies, Anderson UK, shows the effects of Dutch elm
and May focused first on building disease, a fungus spread by elm bark
Aridity, however, also a mathematical model to show beetles accidentally introduced to
weakens plants and makes how a microorganism could affect Europe and America from Asia.
them susceptible to pathogens a population. This led to a set of
that thrive in dry conditions. equations that they hoped would of disease, the total would remain
These include various forms help explain the real-life impact of more or less the same, with the
of fungi that attack the leaves different kinds of pathogens, from rate of added mice balancing that
of grain crops, legumes, and bacteria and viruses to parasitic at which other mice died.
fruits. These fungi are adapted worms and insect larvae.
to survive in a dormant state For simplicity, the model
as hardened microscopic In their model, a number of mice assumed that the diseases were
bodies in soil. They can exist were divided into three groups: transmitted by contact between
for many years in dry soil, but susceptible (uninfected) mice, infected and uninfected mice. Not
when the soil becomes wet, infected mice, and mice that had all infected mice would die, so the
the fungi must find a host survived infection and were now model also included a recovery rate.
within a few weeks or die. immune. Unlike many earlier Mice that recovered would be
They do not necessarily kill epidemiological models, the total immune, at least initially. Immunity
their host. Recent research population was not a fixed number; to viruses is more or less lifelong,
into chickpeas suggests that mice could be added either by but it is possible to become
although infections from such reproduction or by additions from susceptible again to the same
fungi do increase during a dry other populations. Mice also died bacterial infection as time passes.
spell, the mortality rate of the from natural causes. In the absence Therefore, the calculations also
affected plants goes down included a rate of loss of immunity.
during a drought. Sensibly used,
mathematical models are Putting all this together,
A summer drought produces no more and no less than Anderson and May produced a
only sparse growth of young barley tools for thinking about set of equations to predict the rate
plants. Lack of moisture and too things in a precise way. of population change in the three
much heat reduce their resistance initial groups of uninfected but
to fungi that attack their roots. Roy Anderson and susceptible mice, infected mice,
Robert May and the immune survivors. These
equations could be added together
to give the rate of change for the
total mouse population.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS 71

ECOLOGICAL PROCESSES

Diseases such as effects of hypothetical values. They by the disease. Infection numbers
measles and rubella, found, for instance, that when the rise sharply to a maximum, then
with short infections rate of added mice was highest, the drop away. Epidemics also occur
and lasting immunity, disease had the greatest impact on when a disease is not particularly
will tend to exhibit population numbers. This suggests deadly but slows the population
epidemic patterns. that species with high reproductive growth rate; this has occurred with
rates (introducing large numbers human diseases such as measles
Roy Anderson of uninfected offspring) are most and chickenpox.
likely to have endemic diseases
From their calculations, they within the population, and show Applying the theory
deduced that a disease will persist depressed numbers compared with The characteristics of disease
in a population whose equilibrium species that breed more slowly. and its effects on animal and
point (the rate of new additions, They also explored the differing plant populations are of increasing
balanced by the natural death rate) effects on populations of diseases ecological importance. Food
is greater than the combined of different intensities. producers, for example, benefit from
effects of natural mortality, disease studies into the nature of parasites
deaths, recovery, and transmission Unlike endemic diseases, and the dynamics of diseases that
rate. While the disease is present, in which the population’s level can affect crops and livestock.
that equilibrium point will be lower of infection remains consistent, Conservationists also employ
than if the population were disease epidemics appear in populations epidemiology to predict how exotic
free. If, however, the equilibrium when the growth rate of all infected diseases and invasive parasites
point of a population affected by and uninfected members is low might affect fragile ecosystems. ■
disease is lower than the combined compared to the death rate caused
effects of deaths, recoveries, and
rate of transmission, the disease Venn diagram of ecological epidemiology
will die out. Once a population is
disease free, its equilibrium point Susceptible host
will return to its former level.
no
Matching the real world disease
Anderson and May needed to show
that their model was an accurate no no
predictor of a real-life population. disease disease
They did so by using data from
a study of laboratory mice infected disease
with the bacterial disease
pasteurellosis; the data included no no no
the impact on the population of disease disease disease
adding individuals at different
rates. The observed data confirmed Pathogen Favorable
their predictions, so the two environment
scientists were able to consider the for pathogen

A pathogen strikes when it finds a suitable host in an
environment that favous infection, as shown where the
circles intersect. For instance, diarrheal diseases spread
quickly among sick people in unsanitary conditions.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

72

PFWEEHENYTGUDFIRONENSE’’TZE?

ECOPHYSIOLOGY

IN CONTEXT T he central principle of to its distribution, abundance, and
Darwinian evolution is fertility. Ecophysiology now plays
KEY FIGURE that all organisms, from an important role in helping
Knut Schmidt-Nielsen simple bacteria to complex scientists understand how the
(1915–2007) mammals, are adapted by natural stresses created by climate change
selection to survive in a particular impact on both wild ecosystems
BEFORE niche and habitat. Ecophysiology— and cultivated environments.
1845 The explorer Alexander for which Knut Schmidt-Nielsen’s
von Humboldt reveals that book Animal Physiology (1960) was Managing temperature
plants facing similar ecological a vital inspiration—is the study of Ecophysiology has revealed a
factors also have many an organism’s anatomy and how it number of specific adaptations
analogous features. functions (its physiology), as well as for different environments. For
how these characteristics relate to example, animals that live in colder
1859 Charles Darwin argues the challenges posed by its regions tend to have larger bodies
that organisms evolve because environment. It shows how the and smaller legs, ears, and tails
they are adapting to changed anatomy of an animal or plant is than related species living in
ecological conditions. linked to its ability to survive, and warmer climes. A larger body has
a smaller surface-area-to-mass
AFTER From a physiological ratio, and therefore loses heat more
1966 Australian biochemists viewpoint, freshwater slowly, while smaller appendages
Marshall Hatch and Charles reduce exposure to frostbite.
Slack explain that the most is no more freely
widespread plants are the available in the sea In the most extreme cold, the
ones that photosynthesize than in the desert. feet of a warm-blooded animal
most efficiently. Knut Schmidt-Nielsen are at risk of becoming frozen to
the ground. Mammals in Arctic
1984 Peter Wheeler, a British regions such as musk oxen and
scientist, suggests that human polar bears are adapted for life in
bipedalism—the ability to these conditions by having thick
walk on two legs—evolved as hairs to insulate their feet.
a thermoregulatory adaptation
that reduces the body’s In the Antarctic, the undersides
exposure to direct sunlight. of penguins’ feet are insulated
by a thick layer of fat. Penguins
also have a heat-exchange (or
counter-current) mechanism in

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS 73

ECOLOGICAL PROCESSES

See also: Evolution by natural selection 24–31 ■ Ecological niches 50–51
■ Competitive exclusion principle 52–53 ■ Ecological stoichiometry 74–75

their legs. The warm blood arriving cooler than the air outside, so the Knut Schmidt-Nielsen
from the body is cooled to near moisture it carries condenses in
32°F (0°C) by the chilled blood the nose. This creates the cool, Knut Schmidt-Nielsen grew
arriving from the feet, which damp conditions needed to chill up in the Norwegian town of
warms to body temperature in the next in-breath. Trondheim. His interest in the
the process. way animal physiology related
Future challenges to habitat was inherited from
Gazelles in Africa use a similar Today ecophysiology is becoming his grandfather who, years
counter-current system to cool their increasingly focused on plants, before Knut’s birth, had
body temperature. They are able to fungi, and microbes. Like animals, released thousands of flounder
chill the blood entering their head, they have to adapt to survive—and (a marine fish) hatchlings into
giving them an advantage over studying them offers the possibility a freshwater lake. Although
their predators, who often overheat. of vital discoveries for commercial the fish thrived, they were
Camels have a heat-exchange and conservation purposes. ■ unable to breed because their
system in their nasal cavity, which reproductive physiology was
reduces the amount of water lost in Emperor penguins survive freezing adapted for life in salt water.
their breath. Hot, dry air is inhaled Antarctic temperatures thanks in part
and mixes with moisture inside to the way their bodies have evolved Schmidt-Nielsen joined
the nose before traveling to the to adapt to the harsh environment. Duke University, North
lungs. The exhaled air is much Carolina, in 1954. He built a
climate-controlled space for
keeping desert animals, where
he considered the anatomy
of camels, gerbils, and other
species able to live for long
periods without water. He also
investigated the respiratory
systems of birds and the
buoyancy of fish. His 1960
textbook Animal Physiology
is still a classic work.

Key works

1960 Animal Physiology
1964 Desert Animals
1972 How Animals Work
1984 Scaling
1998 The Camel’s Nose:
Memoirs of a Curious Scientist

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

74

CALHLEMLIIFCEALIS

ECOLOGICAL STOICHIOMETRY

IN CONTEXT Every living organism— The field of ecological stoichiometry
from tiny ocean algae was comprehensively described
KEY FIGURES to a mighty redwood—is for the first time by American
Robert Sterner (1958–), made up of chemical elements biologists Robert Sterner and James
James Elser (1959–) in varying ratios. Ecological Elser; in Ecological Stoichiometry
stoichiometry considers the (2002), they used mathematical
BEFORE balance of these elements, and models to demonstrate the
1840 German biologist and how the ratios change during application at every level, from
chemist Justus von Liebig chemical reactions. Studying molecules and cells to individual
asserts that the limitations such ratios throws light on the plants and animals, populations,
on agriculture productivity are way the living world operates, communities, and ecosystems.
primarily chemical. revealing how organisms obtain
the nutrients and other chemicals Key chemicals
1934 US oceanographer Alfred they require for life from the In ecological research, the three
Redfield measures the atomic resources in their environment. main elements examined are
ratio of carbon, nitrogen, and carbon (C), nitrogen (N), and
phosphorus (C:N:P) in plankton Individual organisms also phosphorus (P), because each
and seawater, and finds it to be show differences in plays a vital role. Carbon is a basic
relatively consistent in all building block of all life and an
oceans. The Redfield Ratio soon stoichiometry during their life important part of many chemical
becomes a benchmark for such cycles. Young organisms may processes. Nitrogen is a major
research in all habitats. have different compositions constituent of all proteins, while
phosphorus is crucial for cell
AFTER from older ones … development and storing energy.
2015 In “Ocean stoichiometry, Robert Sterner and
global carbon, and climate,” An organism’s C:N:P ratio is not
Robert Sterner highlights James J. Elser necessarily consistent. Plants have
inconsistencies in C:N:P ratios a variable ratio: they can adjust the
in phytoplankton, which absorb balance of their elements according
more atmospheric carbon in to their environment. For instance,
low-nutrient, low-latitude ocean the proportion of carbon in their
surface waters and adjust their chemical makeup can rise on a
ratios accordingly. particularly sunny day because
more photosynthesis occurs—the
process by which they take carbon

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

ECOLOGICAL PROCESSES 75

See also: Ecophysiology 72–73 ■ The food chain 132–133 ■ Energy flow through The Growth
ecosystems 138–139 ■ The foundations of plant ecology 167 Rate Hypothesis

Controlling ecological stoichiometry ratios Cancer research is one area
where stoichiometry is now
A locust eats grass that may contain six times being employed. Evidence is
as much carbon as it needs. To get the right growing for a theory called the
balance, it excretes carbon or breathes it out Growth Rate Hypothesis
as CO2. Locusts are widely used in research (GRH), which may help explain
because they are easy to breed. why some cancerous tumors
grow at faster rates than the
KEY Nitrogen LOCUSTS GRASS rest of the body.
Carbon 5:1 33:1
The hypothesis states that
dioxide from the air and use the may adjust its digestive enzymes organisms with high C:P
sun’s energy to convert it into the and excrete it, store it as fats, or raise (carbon:phosphorus) ratios,
nutrients they require. its metabolic rate to burn it off, such as fruit flies, have more
breathing out the excess carbon as ribosomes in their cells, which
Higher up the food chain, CO2. Overuse of such mechanisms enables them to grow and
animals have largely fixed C:N:P to redress a high imbalance can, reproduce more rapidly.
ratios, so they must deploy various however, affect fitness, growth, and Around half of all phosphorus
mechanisms to deal with any reproduction. An animal that eats in an organism is in the form
imbalances of chemicals entering other animals has less work to do, of ribosomal RNA (rRNA); it is
the body. If an insect or animal because its prey’s C:N:P ratio present in every cell, creating
herbivore is getting too much carbon closely matches its own. However, proteins to build new cells and
from its plant diet, for instance, it the size of its prey population is still grow the body. Applying
determined by the plants in its biological stoichiometry,
environment because plants with a James Elser and his team
high carbon ratio can only support have shown that fast-growing
a small food chain of consumers. tumors have a much higher
phosphorus content than
normal body tissue. Such
research may help scientists
understand how tumor growth
could be controlled.

Understanding our world
Food chains are one area of study;
ecological stoichiometry covers just
about everything and all the links
in between. By discovering how
the chemical content of organisms
shapes their ecology, scientists are
also learning how environments
can be better managed. Their
findings may significantly influence
the future of life on Earth. ■

The desert locust (Schistocerca Malignant lung tissue (seen
gregaria) has to eat vast quantities here) and cancerous colon tissue
of carbon-rich plants in order to get both had the highest phosphorus
enough nitrogen and phosphorus content in research exploring the
to maintain its C:N ratio. rapid growth rates of tumors.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

76

IFSEAPROWITESREFLUFL

NPROENDCAOTNOSRUSMOPNTITVHEEEIRFFPERCETYS OF

IN CONTEXT M any descriptions of risks of being eaten. The lethal role
ecosystems focus on of predators is obvious, but their
KEY FIGURE predator–prey interactions nonlethal (nonconsumptive) role
Earl Werner (1944–) in which predators kill and prey are can have an even bigger impact on
eaten. However, American ecologist an ecosystem. Potential prey are
BEFORE Earl Werner and others have shown forced to change their way of life
1966 American ecologist that the mere presence of a predator in order to avoid being killed.
Robert Paine conducts a affects the behavior of prey.
series of groundbreaking In 1990, Werner studied the
field experiments to highlight Apart from apex predators, all effects of green darner dragonfly
the crucial effects of a predator animals must balance the need to larvae on toad tadpoles. He noticed
on the community in which sleep, reproduce, and feed with the that when the predatory larvae
it lives.
In the presence of predators …
1990 Canadian biologists
Steven Lima and Lawrence prey move on to prey spend more time
Dill analyzed the decision- other areas even if there is hiding in sheltered habitats
making of organisms that are than feeding in the open.
at the greatest risk of being less food there.
preyed on by other creatures.
Even without preying on
AFTER them, predators can cause prey to
2008 American behavioral
biologist and ecologist John fail to thrive.
Orrock teams up with Earl
Werner and others to produce
mathematical models to
explain the nonconsumptive
effects of predatory animals.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS 77

ECOLOGICAL PROCESSES

See also: Evolution by natural selection 24–31 ■ Predator–prey equations 44–49 ■ Ecological niches 50–51
■ Competitive exclusion principle 52–53 ■ Mutualisms 56–59 ■ Optimal foraging theory 66–67

bullfrog’s new behavior gave it
a competitive advantage over the
green frog by making it bigger.

A green darner dragonfly laying when predatory dragonfly larvae Terrestrial animals
its eggs in a pond. The larvae that were introduced to the tank, both Early studies of nonconsumptive
hatch out are predators and have been prey species became less active effects (NCEs) were concerned with
shown to influence the behavior of their and chose different places in which aquatic organisms under laboratory
tadpole prey. to swim. The bullfrog tadpoles grew conditions, but more work has now
more quickly than they had in a been done in the wild with land-
were in the tank, the tadpoles were predator-free tank, but the green dwelling animals. German field
less active, swam to other parts of frog tadpoles decreased their research published in 2018
the tank, and metamorphosed into feeding activity and grew more focused on lynx and their roe deer
adults when they were smaller. The slowly. Werner concluded that for prey. When lynx were present,
predator had changed the toads’ prey species there was a trade-off researchers found that the roe deer
morphology and their behavior just between the need to grow as fast avoided areas they knew to be
by being there. as possible and the risk of predation. high-risk, both during the day and
Growing more quickly requires on summer nights when nocturnal
In 1991, Werner investigated more feeding activity, and this in predation is more common. The
what happened when more than turn increases the chances of being deer treated some grazing areas as
one prey species was involved. In eaten by a predator. As the larvae’s out of bounds, presumably due to
the absence of a predator, bullfrog presence altered the behavior of fear of being attacked by lynx.
and green frog tadpoles grew at the prey species differently, the
virtually identical rates. However, Wherever there are predators,
they exert NCEs. They also affect
some sessile (nonmoving) species,
as well as mobile prey. This can
happen when certain dominant
competitors are displaced by
predators and, in their new
habitats, outcompete sessile
animals for food. Small fish that
are displaced, for example, could
outcompete sponges for food. ■

… species react [to predators]
by reducing activity and
altering space use.
Earl Werner

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

NOARTDUERRAINL

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

GWOTHRELD

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

80 INTRODUCTION

Aristotle’s History of A private collection of natural The Natural History
Animals groups living things history curiosities is displayed Museum in London opens its
based on their species, in a
at Oxford University’s doors to the public, free of
scala naturae that places Ashmolean Museum, the charge. It now houses 80
organisms into 11 grades. world’s first public museum.
million specimens.

C.350 BCE 1683 1881

1665 CE 1758

Micrographia, the richly The 10th edition of Systema
illustrated book by Robert Naturae by Carl Linnaeus
Hooke, reveals microscopic
structures to a wider audience. classifies a range of plant
and animal species using

his binomial system.

People have long marveled at In keeping with the prevailing to adopt this new technology: his
the variety of life, celebrating ideas of the Catholic Church, the book Micrographia (1665) inspired
nature’s gifts in prehistoric natural world was seen as static others to do likewise. Able to view
cave art that dates back 30,000 years and unchanging. specimens magnified to 50 times
or more. In Ancient Greece in the 4th their actual size, he made meticulous
century BCE, Aristotle made an early An age of discovery drawings of microsopic life, and
attempt to classify living organisms; The age of great expeditions also coined the term “cell” after
his 11-grade scala naturae (“ladder of of discovery revealed previously examining plant fibers. Hooke also
life”) placed humans and mammals uncharted regions and their suggested a living origin for fossil
at the top, and descended through animals and plants. In his History fragments found in rocks.
other, more “primitive” animals of the Animals (1551–58), Swiss
to plants and then minerals. A physician and naturalist Conrad Classifying variety
thousand years later, the medieval Gesner included some of the recent English vicar John Ray’s History of
world still considered variations finds from the New World and the Plants (1686–1704) was the botanical
on Aristotle’s system to be valid. Far East, as well as relying on equivalent of Gesner’s earlier work,
There were several reasons for this. classical literature. The five-volume listing some 18,000 species in three
Without microscopes, nothing was work reflected his division of huge volumes. Ray also produced
known of cells and microorganisms. animals into mammals; reptiles and a biological definition of a species,
Without the means to explore amphibians; birds; fish and aquatic remarking that “one species never
underwater, science’s knowledge animals; and snakes and scorpions. springs from the seed of another.”
of aquatic creatures was limited, Swedish botanist Carl Linnaeus,
and many parts of the world were The invention of the microscope the “father of taxonomy,” first
still unknown to Western scientists. also had a major impact. English published Systema Naturae in 1735,
scholar Robert Hooke was quick

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS 81

ORDERING THE NATURAL WORLD

Carl Woese Norman Myers’s
establishes a new, third “biodiversity hotspots”
category of organisms— concept identifies ten hotspots
where conservation efforts
the prokaryotes. should preserve rare species.

1977 1988 2018
1942 1988

Ernst Mayr develops the Edward O. Wilson coins The IUCN Red List shows that
biological species concept, the term biodiversity more than 26,000 species –
and later identifies the more than 27 percent of all
which categorizes species key human threats those assessed—are at
based on their ability to to biodiversity. risk of extinction.
breed with each other.

but it is the 10th edition from 1758 but a population that can breed new domains. As of 2018, about
that founded the modern zoological only among themselves. Mayr went 1.74 million extant plant and animal
naming system. Two volumes of on to explain how if groups within species have been described, but
Linnaeus’ work are devoted to a species become isolated from the estimates of the total number range
plants and animals, which he rest of the population, they may from 2 million to 1 trillion.
divided into classes, orders, genera, start to differ from the rest, and
and species. The binomial system, over time, through genetic drift and The threat to diversity
in which every species is given a natural selection, may even evolve By the late 20th century, however,
generic name followed by a specific into new species. alongside a growing knowledge
name, is still in use today. Linnaeus of the scale and critical role of
also wrote a third volume on rocks, Modern technological advances, biodiversity—and of how evolution
minerals, and fossils. including electron microscopy and can destroy species as well as
mitochondrial DNA analysis, have create them—American ecologist
Species concepts revealed much information—some E.O. Wilson and others made the
Building on Darwin’s theory of of it surprising—about the number world aware that human activity
evolution by means of natural of species and the relationships was responsible for causing a rapid
selection, German-American between them. In 1966, striving to acceleration in the extinction rate.
evolutionary biologist Ernst Mayr reflect the intricacies of evolution, Some have even warned that Earth
cemented the biological concept of German entomologist Willi Hennig could be on the verge of a sixth
species in his Systematics and the proposed a new taxonomic system mass extinction. Many policies are
Origin of Species (1942). He argued of clades—groups of organisms now being proposed to counter
that a species is not just a group of based on a common ancestor. In this, including the protection
morphologically similar individuals, the 1970s, American biologist Carl of biodiversity hotspots. ■
Woese classified all life into three

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

82

IIOOSNFFSANTLOHALMTETUEMHTRAIHENRIGTNVHSGEELROEUS

CLASSIFICATION OF LIVING THINGS

IN CONTEXT F rom the beginning of Aristotle placed animals in a scala
recorded history, people naturae (ladder of nature), with 11
KEY FIGURE have attempted to identify grades distinguished by their mode
Aristotle (c. 384–322 bce) organisms according to their uses. of birth. Those in the top grades
Egyptian wall paintings from gave birth to live, hot, wet offspring;
BEFORE c. 1500 bce show, for example, that those in the lower grades to cold,
c. 1500 bce Different people understood the medicinal dry eggs. Humans were at the very
properties of plants are properties of many plants. In the top of the scale, with live-bearing
recognized by ancient text History of Animals, written tetrapods (four-legged creatures),
Egyptians. in the 4th century bce, the Greek cetaceans, birds, and egg-laying
philosopher and scholar Aristotle tetrapods lower down. Aristotle
AFTER made the first serious attempt to placed minerals on the bottom
8th–9th centuries ce Islamic classify organisms, studying their grade of his scale, with plants,
scholars of the Umayyad and anatomy, life cycles, and behavior. worms, sponges, larva-bearing
Abbasid dynasties translate insects, and hard-shelled animals
many of Aristotle’s works Features of classification on the levels above.
into Arabic. Aristotle divided living things into
plants and animals. He further If any person thinks the
1551–58 Conrad Gessner’s grouped about 500 species of examination of the rest
History of Animals classifies animals according to obvious of the animal kingdom
the animals of the world into anatomical features, such as an unworthy task, he must
five basic groups. whether they had blood, were hold in like disesteem
“warm-blooded” or “cold-blooded,”
1682 John Ray publishes his whether they had four legs or more, the study of man.
History of Plants, which lists and whether they gave birth to live Aristotle
more than 18,000 species. offspring or laid eggs. He also noted
whether animals lived in the sea,
1735 Carl Linnaeus devises a on land, or flew in the air. Most
system of binomial names, the significantly, Aristotle used names
first consistent classification of for his groupings that were later
organisms, according to which translated into the Latin words
he names every species listed “genus” and “species”—terms
in his Systema Naturae. that are still used by modern
taxonomists to this day.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

ORDERING THE NATURAL WORLD 83

See also: The microbiological environment 84–85 ■ A system for identifying all nature’s organisms 86–87 ■ Biological
species concept 88–89 ■ Microbiology 102–103 ■ Animal behavior 116–117 ■ Island biogeography 144–149

An octopus blends in with its
surroundings. The ability of these
creatures to change color was one of
Aristotle’s many accurate observations.

While Aristotle’s system of
classification was rudimentary, it
was based largely on first-hand
observations, many of which were
made on the island of Lesvos. He
recorded things that noone else
had described, including that
young dogfish grew inside their
mothers’ bodies, male river catfish
guard eggs, and octopuses
can change color. Most of his
observations were good—and some
were confirmed only centuries later.

The great chain of being The Swiss doctor Conrad Gessner (reptiles and amphibians); birds;
Despite its limitations, Aristotle’s wrote the first modern register of fish and aquatic animals; and
method of classification heavily animals—also called History of snakes and scorpions. In 1682,
influenced every later attempt at Animals—in the mid-16th century. the English naturalist John Ray
grouping animals and plants until This monumental five-volume work produced the equivalent register
the 18th century. Medieval was based on classical sources but for botany with his History of
Christianity developed his scala included newly discovered species Plants. Within little more than
naturae as a “great chain of being,” from East Asia. It covered the main 50 years, the classification of
with God at the top of a strict animal groups as Gessner saw living things would be completely
hierarchy, humans and animals them: live-bearing quadrupeds transformed by Carl Linnaeus’s
beneath, and plants at the bottom. (mammals); egg-laying quadrupeds Systema Naturae. ■

Aristotle Aristotle was born in Macedonia, scholar Ptolemy and King
ancient Greece. Both his parents Alexander the Great. In 335 bce,
died when he was young, and he he established his own school
was raised by a guardian. Aged at the Lyceum in Athens. After
17 or 18, Aristotle joined Plato’s Alexander’s death in 322 bce,
Academy in Athens, where he Aristotle fled the city, and died
studied for 20 years, writing on on the island of Euboea in the
physics, biology, zoology, politics, same year.
economics, government, poetry,
and music. Later, he traveled Key works
to the island of Lesvos with a
student named Theophrastus 4th century bce
to study the island’s botany and History of Animals
zoology. Much of his History On the Parts of Animals
of Animals was based on On the Generation of Animals
observations he made there. On the Movement of Animals
Aristotle taught both the future On the Progression of Animals

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

84

BNOOYOUFRTTMHHIIINCENQRGHUOEEISLRSCPYCOAPPEESS

THE MICROBIOLOGICAL ENVIRONMENT

IN CONTEXT L eafing through the pages of Although it is not known for
Micrographia, a 17th-century certain who developed the first
KEY FIGURE reader would have been microscopes, they were certainly
Robert Hooke (1635–1703) astonished. Here, in English in use by the 1660s. The early
scientist Robert Hooke’s seminal instruments were unreliable—due
BEFORE 1665 book, were many detailed to the difficulty of making the
1267 English philosopher illustrations of structures previously lenses—and scientists had to be
Roger Bacon discusses the use hidden from the human eye due to inventive and work around the
of optics for looking at “the their minuscule size. Hooke’s problem. At first, Hooke had
smallest particles of dust” in microscope magnified things by a difficulty seeing his specimens
his Opus Majus Volume V. factor of fifty, but the accuracy of clearly, so he invented an improved
his drawings also owes much to light source, named a “scotoscope.”
1661 Microscopic drawings by his painstaking approach. Hooke
English architect Christopher would make numerous sketches Hooke’s book is more than just
Wren impress Charles II, who from many different angles before an accurate representation of what
commissions more drawings combining them into a single image. he saw through the lens; it also
from Robert Hooke. theorizes on what the images reveal
… in every little particle… about the workings of the organisms
AFTER we now behold almost as he studied. For example, when
1683 Dutch amateur scientist great a variety of Creatures, looking at a wafer-thin specimen of
Antonie van Leeuwenhoek as we were able before to cork, Hooke saw a honeycomb-like
uses a microscope to observe pattern, the elements of which he
bacteria and protozoa, and reckon up in the whole described as “cells”—a term that is
publishes his findings with Universe itself. still used today.
the Royal Society of London. Robert Hooke
Microscopic marvels
1798 Edward Jenner, an Micrographia inspired many
English physician and other scientists to investigate the
scientist, develops the world’s microscopic world. Following
first vaccine—for smallpox— notes and diagrams from Hooke’s
and publishes An Inquiry into book, Dutch scientist Antonie
the Causes and Effects of the van Leeuwenhoek was able to
Variolae Vaccinae. construct his own microscopes.
He achieved magnifications of
more than 200 times actual size.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

ORDERING THE NATURAL WORLD 85

See also: Classification of living things 82–83 ■ A system for identifying all nature’s organisms 86–87 ■ Microbiology
102–103 ■ Thermoregulation in insects 126–127

Van Leeuwenhoek examined [Micrographia is] … the
samples of rainwater and stagnant most ingenious book that I
pondwater and marveled at the
multitude of life he saw there. He ever read in my life.
identified single-celled protozoa, Samuel Pepys
naming them “animalcules,” and
went on to discover bacteria. He English diarist
also made many observations of
human and animal anatomy, organ. Grew also spotted pollen The compound eye and brain of a
including blood cells and sperm. grains and noted that they were bee, drawn by Jan Swammerdam and
transported by bees. published in A Treatise on the History
While van Leeuwenhoek of Bees, shows the eye exterior (left)
examined water samples, fellow Since the early days of and the eye dissected (right), with the
Dutchman Jan Swammerdam was microscopy, devices have grown brain cross-sectioned below.
placing insects under his own in sophistication. The electron
microscope. He published records microscope, first used in 1931, uses
of all manner of insects depicted in beams of electrons—rather than
the finest detail and uncovered light—to reveal objects, allowing
much about their anatomy. scientists an even closer look.
Swammerdam’s most influential Electron microscopes provide views
work was Life of the Ephemera of up to one million times actual
(1675), which recorded in great size—600 times greater than most
detail the life cycle of the mayfly. modern light microscopes. ■

In England, Nehemiah Grew
used microscopy to examine a
wide range of plants. He was the
first to identify flowers as being
the sexual organs of plants. In The
Anatomy of Plants (1682), Grew
named the stamen as the male
organ and the pistil as the female

Robert Hooke Born on the Isle of Wight, England, include some early insights into
Hooke showed an early interest the wave theory of light; the
in science. A small inheritance construction of some of the
allowed him to attend the earliest telescopes; and the
prestigious Westminster School, formulation of Hooke’s Law.
where he excelled, earning a place Hooke was also a respected
at Oxford University. There he architect, an activity that made
assisted the natural philosophers him a wealthy man.
John Wilkins and Robert Boyle.
In 1662 Hooke became the first Key works
curator of experiments for the
Royal Society of London. In 1665 1665 Micrographia
he became Professor of Physics at 1674 An Attempt to Prove
Gresham College. the Motion of the Earth
1676 A Description of
Like many scientists of his Helioscopes and Some
day, Hooke had a broad range of Other Instruments
interests. His achievements

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

86

ITTTFHHHYEEEOMNKUNAISDMOOWLEOSNLSOEOTTDFGKTENHOOINWFGS,

A SYSTEM FOR IDENTIFYING
ALL NATURE’S ORGANISMS

IN CONTEXT Before the 18th century, there characteristics, such as similarity
was no consistent naming of body parts, size, shape, and
KEY FIGURE system for animals and methods of getting food. Linnaeus
Carl Linnaeus (1707–78) plants. Botanists and zoologists also adopted a precise two-word
often did not know if they were (binomial) name for each species.
BEFORE discussing the same organism.
1682 John Ray, an English To overcome the problem, Swedish Early insights
botanist, proposes that the botanist Carl Linnaeus invented By 1730, while still a student,
plant kingdom be divided a revolutionary system, which is still Linnaeus began to have issues
into trees and two families in use today. He is known as the with the system for classifying
of herbaceous plants. “father of taxonomy”—the science of plants developed by Joseph Pitton
naming and classifying organisms. de Tournefort more than 30 years
1694 French botanist Joseph earlier. For Linnaeus, the
Pitton de Tournefort publishes Linnaeus divided both the plant characteristics of individual species
Eléments de Botanique. This and animal kingdoms into classes, needed to be analyzed more closely
beautifully illustrated book orders, genera, and species. in order to produce a more thorough
becomes the botanical Organisms were placed in these taxonomic system.
classification benchmark levels on the basis of shared
for half a century.
Collaborative work is To work together over
AFTER crucial for the advancement long distances, scientists
1957 Sir Julian Huxley is the of scientific knowledge.
first to use the term “clade” to need things to be
describe a common ancestor named with accuracy.
and all of its descendants.
If you do not know Misunderstandings
1969 Robert Whittaker, an the names of things, cause discrepancies in
American ecologist, argues for
a five-kingdom categorization the knowledge of scientific knowledge.
of life: Monera, Protista, Fungi, them is lost.
Plantae, and Animalia.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS 87

ORDERING THE NATURAL WORLD

See also: Classification of living things 82–83 ■ Biological species concept 88–89
■ A modern view of diversity 90–91

In natural science, been known by long impractical Carl Linnaeus
the principles of truth names—for example, Plantago foliis
ought to be confirmed ovato-lanceolatis pubescentibus, Born in rural southern Sweden,
spica cylindrica, scapo tereti. Linnaeus was educated at the
by observation. Linnaeus called this plant Plantago University of Uppsala, where
Carl Linnaeus media, which was sufficient to he began teaching botany in
identify it. As well as being concise, 1730. He spent three years
In 1732, Linnaeus joined an the Linnaean system describes in the Netherlands, and, on
expedition to Lapland, where he relationships between species. returning to Sweden, he
collected about 100 unidentified divided his time between
species. These formed the basis of Later developments teaching, writing, and plant-
his book Flora Lapponica, in which Linnaeus constantly expanded collecting expeditions. At
he aired his ideas about plant Systema Naturae; its 10th edition Uppsala, 17 of his students
classifications for the first time. (1758) became the starting point embarked on expeditions all
for modern animal classification. over the world. Linnaeus was
Three years later, Linnaeus It was he who suggested that a friend of Anders Celsius, the
wrote about his idea for a new humans were members of the inventor of the temperature
hierarchical classification of plants primate family. Much later, aided scale. After his friend’s death,
in a further book, Systema Naturae, by Charles Darwin’s theory of Linnaeus reversed the scale
and thereafter in arguably his evolution by natural selection, so that freezing point was
greatest work, Species Plantarum, biologists accepted that a 32°F (0°C) and boiling point
published in 1753, which covered classification should reflect the 212°F (100°C). Linnaeus
7,300 species. Previously, plants had principle of common descent, has been described as the
which led to the methodology “prince of botanists,” and the
known as cladistics. ■ philosopher Rousseau said of
him “I know no greater man
Whales were once thought to be on Earth.” Linnaeus is buried
fish, and were classified as such in in Uppsala Cathedral; his
an early edition of Linnaeus’s Systema remains constitute the type
Naturae. Only later was it understood specimen—the specimen that
that they are actually mammals. represents a species—used for
Homo sapiens.

Key works

1735 Systema Naturae
1737 Flora Lapponica
1751 Philosophia Botanica
1753 Species Plantarum

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

88

IK“SREOEYLPWARTOOEDRDUD”CSATRIVEETLHYE

BIOLOGICAL SPECIES CONCEPT

IN CONTEXT “Species” can be When two groups
defined as population of the same species
KEY FIGURE groups that are able become reproductively
Ernst Mayr (1904–2005)
to reproduce. isolated they
BEFORE evolve separately.
1686 Naturalist John Ray
defines individual plant and The capacity to Eventually, they
animal species as those that interbreed is key become separate
derive from the same seed. to the definition species that cannot
mate with each other.
1859 Charles Darwin’s On the of a species.
Origin of Species introduces
the idea that species evolve B y the early 20th century, it some point become separated by
through natural selection. was accepted that multiple geography, mate choice, feeding
species could evolve from a strategies, or other means, and then
AFTER common ancestor. However, it was begin to change through natural
1976 The Selfish Gene by not clear how this evolution process selection or genetic drift. Over time,
Richard Dawkins popularizes actually occurred. In fact, there was as a result of this initial separation,
gene-centered evolution: natural some debate about precisely what a two distinct species evolve, which
selection at a genetic level. “species” was. In 1942, evolutionary cannot interbreed. This type
biologist Ernst Mayr proposed a of speciation commonly occurs
1995 The Beak of the Finch new definition of species: groups in small populations of creatures
by Jonathan Weiner follows of interbreeding natural populations on remote islands.
the work of biologists Peter that are “reproductively isolated
and Rosemary Grant on the from other such groups.” Key differences
Galapagos Islands. The biological species concept is
What this means is that two primarily focused on the breeding
2007 Massimo Pigliucci and populations of the same species potential between organisms. Two
Gerd B. Müller use the term living in the same area may at
“eco-evo-devo” to suggest how
ecology is among the factors
affecting evolution.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS 89

ORDERING THE NATURAL WORLD

See also: Evolution by natural selection 24–31 ■ The role of DNA 34–37 ■ The selfish gene 38–39
■ Competitive exclusion principle 52–53

organisms may appear identical Endless forms Sometimes, too, different animal
and live in the same place, but this most beautiful and species are able to mate and
does not mean that they are the most wonderful have produce offspring, as is the case
same species. For example, the of a female horse (Equus ferus
Western Meadowlark (Sturnella been, and are caballus) and a male donkey
neglecta) and Eastern Meadowlark being, evolved. (Equus africanus asinus), which
(Sturnella magna) look similar and Charles Darwin together can produce a hybrid—
have overlapping ranges, but they the mule. However, mules
have evolved to produce different of a species. Geographical themselves are generally incapable
songs. This prevents them from separation alone does not prevent of reproduction, and therefore the
mating with each other, making species from reproducing if they horse and donkey remain different
them two distinct species. are brought together. Evolutionary species. Another example is the
divergences—such as the different liger, a zoo-bred hybrid of a female
Another scenario is when mating songs of the Western tiger and a male lion.
members of the same species look and Eastern Meadowlarks—are
very different, but because they can what prevents interbreeding. Such anomalies highlight the
mate and reproduce they are still complexities of defining a species.
considered to be the same species. The biological species concept The biological species concept
The most obvious instance of this is is not applicable to asexual remains the most popular, but
the domestic dog (Canis familiaris), organisms, such as bacteria, scientists are now looking at the
a species in which there are great or asexual creatures—for example, idea of shared genes, and using
differences between individuals. species of whiptail lizard. DNA sequence analysis. To date,
However, as is also evident, different no one has come up with a single
breeds are capable of reproduction definition that covers every known
with each other, and therefore species, and it seems unlikely
belong to the same species. that anyone ever will. In the
absence of better models, Ernst
Complex permutations Mayr’s biological species concept
According to the biological species provides an extremely useful
concept, the potential for inter- way of thinking about species
breeding is key to the definition and evolution. ■

Alternative species concepts

Male fireflies are an example of Although Mayr’s idea about be based on genetics, such as
a typological species. They emit a biological speciation is perhaps DNA or RNA base sequences, or
pattern of flashes to attract females, the most common way to define on phenotypes, such as the size
who recognize their species’ code species and explain how they of certain body parts or
and flash back—if they wish to mate. evolve, it is far from the only particular markings, such as the
one. In fact, there are more than arrangments of spots on insects’
20 recognized species concepts, wings. The evolutionary species
ranging across two broad groups: concept is based on species
typological and evolutionary lineages. A species is defined as
concepts. Typological species the organisms that share a
concepts are based on the idea lineage from the time when the
that a population of individuals of species initially split off until
the same type—or sharing the extinction, or until an additional
same set of traits—are what splitting off and creation of a
makes up a species. The traits can new species.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

90

IPOCNRRLTIEGMOAAARSNRLEISYYVMECKRSLINAUGLSDTOEMRS

A MODERN VIEW OF DIVERSITY

IN CONTEXT B efore biologists had the with simple nucleus-free cells),
equipment and techniques and eukaryotes (such as animals
KEY FIGURE needed to scrutinize the and plants with larger, more
Carl Woese (1928–2012) microscopic structure of living complex cells).
things, biological diversity was
BEFORE split simply into animal-like and In the 1970s, the American
1758 Systema Naturae (10th plant-like organisms. Then, in the biologist Carl Woese claimed that
edition) by Carl Linnaeus 20th century, better microscopes even this system failed to account
classifies known life into two began to reveal deeper differences for the diversity among microbes—
kingdoms: animals and plants. that could not be seen with the the smallest living things. He
naked eye. By the 1960s, picking focused on ribosomes—minuscule
1937 French biologist Edouard up on an idea first proposed by
Chatton divides life into Edouard Chatton in the 1930s, the Sulfur-dependent archaea
prokaryotes (bacteria) and need for a new division of living organisms thrive in the hot geothermal
eukaryotes (organisms with things emerged, placed between pools of Yellowstone National Park,
complex cells). prokaryotes (such as bacteria, Wyoming, in conditions that would
kill most other organisms.
1966 German biologist Willi
Hennig establishes a system
of classification based on
clades—groups of organisms
based on common ancestry.

1969 American ecologist
Robert Whittaker divides
life into five kingdoms:
bacteria, protists, fungi,
plants, and animals.

AFTER
2017 A consensus among
biologists accepts a seven-
kingdom classification of life.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

ORDERING THE NATURAL WORLD 91

See also: Early theories of evolution 20–21 ■ Evolution by natural selection 24–31 Kingdom of their own
■ The role of DNA 34–35 ■ A system for identifying all nature’s organisms 86–87
For most of the history of
Carl Woese’s three-domain tree biology, fungi were considered
to be plants. Even the great
Bacteria Archaea Eukaryotes classifier of organisms Carl
Cyanobacteria Thermoproteus Animals Linnaeus included them in his
Methanococcales Plants kingdom Plantae. It was only
Bacteroides Fungi with the invention of more
Purple bacteria Extreme Protists powerful microscopes that
halophiles the differences in fungi began
to be better understood. It is
According to Carl Woese, all organisms can be now known that chitin, a
separated into three main categories or “domains.” complex carbohydrate and
These divisions are based on similarities in the component of fungus cell
ribosome structure found in the cells of the groups walls, is not found in plants.
of organisms within each domain. Also, fungi make their food
by digesting rotted material,
grains that all cells need in order to A decade before Woese proposed whereas plants make food by
make protein—and devised what he his theory, Robert H. Whittaker absorbing light energy in
called the “three-domain system.” had recognized animals, plants, photosynthesis.
This gave him a new perspective and fungi as separate eukaryotic
on the branches of Charles Darwin’s kingdoms, with all other eukaryotes DNA analysis shows that
evolutionary “tree of life.” Woese placed in the protist kingdom, fungi are far removed from
found big differences in the and bacteria constituting a plants in the evolutionary
chemical makeup of ribosomes fifth kingdom. Whittaker’s protist tree of life: they are, in fact,
among tiny microbes, with one kingdom covered eukaryotic genetically closer to the
group as far from other prokaryotes organisms such as amoebas that branch that gives rise to
as bacteria are from humans. did not fit the other categories. animals. These same studies
Some protists were closer to show that certain aquatic
Revising the tree of life animals, some closer to plants, molds—traditionally classified
Woese’s third domain of organisms, and others not close to either. as fungi—are not related to
known as archaea, is superficially They did not match the tree of life fungi, while some disease-
similar to bacteria, but has some model, in which clades—groups causing microbes are fungi
strange properties. Many thrive in of organisms with a common that have evolved to become
extreme habitats. Some—uniquely ancestry—spring as branches microscopic parasites.
among living things—generate from the previous fork.
methane in oxygen-deprived places, Fungi, such as this bright
such as deep marine sediments, or Woese sought a classification yellow jelly fungus growing on a
inside warm digestive cavities, system that reflected the intricacies fallen tree, are no longer classified
such as those of belching, flatulent of evolution—with main branches as plants. Fungi are genetically
plant-eating mammals. Other on the tree of life splitting into closer to animals.
archaea inhabit lakes that are ten smaller ones, and even tinier twigs
times saltier than seawater, or hot that end in the leaves of individual
acidic pools fed by geothermal heat species. In the future, the complex
that would kill anything else. tree of life may reveal even more
evolutionary categories. ■

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

92

BSSAINAAOVVDSEEYPTTOHHHUEEERMEWAOYRLD IN CONTEXT

HUMAN ACTIVITY AND BIODIVERSITY KEY FIGURE
Edward O. Wilson (1929–)

BEFORE
1993 The UN proclaims
December 29 as the
International Day for
Biological Diversity.

1996 The Song of the Dodo
by American science writer
David Quammen explores
the nature of evolution and
extinction as habitats become
more and more fragmented.

AFTER
2014 The Sixth Extinction
by environmental journalist
Elizabeth Kolbert shows how
humans are causing a sixth
mass extinction of species.

2016 In Half-Earth, Edward
Wilson proposes that Earth
can be saved by dedicating
half of it to nature.

B iodiversity is the variety of
life on Earth—in all forms
and at every level, from
genes to microbes to humans and
all other species, including those
yet to be discovered. Humans rely
on biodiversity for food and fuel,
shelter, medicine, beauty, and
pleasure. For other species, it also
provides nutrients, seed dispersal,
pollination, and reproductive
success. No living thing could
survive without biodiversity.

Ecologists have identified
growing threats to biodiversity,
many of them driven by human
actions. The current rate of species
extinction is thought to be up to
1,000 times greater than it was

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

ORDERING THE NATURAL WORLD 93

See also: Biodiversity hotspots 96–97 ■ Animal ecology 106–113 ■ Island biogeography 144–149 ■ Biodiversity and
ecosystem function 156–157 ■ Biomes 206–209 ■ Mass extinctions 218–223 ■ Deforestation 254–259 ■ Overfishing 266–269

The effects of human activity on biodiversity animals because they may no
longer be able to find places to feed
The five human activities or rest along their normal routes.
that most seriously affect Native species and ecosystems are
biodiversity on Earth can be also disrupted by the introduction,
represented by HIPPO, the accidentally or deliberately, of new
acronym devised by Edward species. These invasive species.
Wilson, with the relative can threaten the food supply or
severity of each reflected other resources of native species,
in the order of the letters. carry disease, and become a
predatory threat. The brown tree
1. Habitat destruction snake, for example, was brought
accidentally to the island of Guam
5. Overharvesting 2. Invasive on a cargo ship, and has caused
by hunting species the extirpation (the extinction of a
or fishing species in a particular area) of 10 of
the island’s 11 native bird species.
4. Human population 3. Pollution
Air and water poisoning
before 1800, when humans began loss of habitats that once supported Any kind of pollution threatens
to dominate the planet. The first particular species. This destruction biodiversity, but air and water
use of the term “biodiversity,” in can occur as a result of natural pollution are particularly harmful.
1988, was by American biologist causes, such as fire or flood, or, Burning fossil fuels, for example,
Edward O. Wilson, who became more commonly, through the releases the waste gases sulfur
known as the “father of biodiversity.” expansion of agricultural land, dioxide and nitrogen oxide into
He later highlighted five key threats timber harvesting, and overgrazing the air; these return as acid rain,
to biodiversity using the acronym by livestock. Deforestation, in causing water and soil acidification
HIPPO: habitat destruction; particular, has contributed hugely and affecting ecosystem health and
invasive species; pollution; human to habitat loss, with around half of biodiversity. Ozone emissions at
population; and overharvesting by the world’s original forests now ground level can also damage cell
hunting and fishing. cleared, mainly for agricultural use. membranes on plants, curbing their
growth and development. ❯❯
Habitat wreckers Some habitats are not destroyed
The Red List of the International but rather broken up or divided into It is that range of biodiversity
Union for Conservation of Nature more isolated units by human that we must care for—the
(IUCN) includes more than 25,000 interventions, such as building whole thing—rather than
threatened species. Of these, dams or other water diversions.
85 percent are endangered by the This habitat fragmentation is just one or two stars.
particularly dangerous for migratory David Attenborough

British broadcaster and naturalist

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

94 HUMAN ACTIVITY AND BIODIVERSITY

Edward O. Wilson We should preserve Rapid population growth has
every scrap of biodiversity generated further damage to the
Born in Alabama in 1929, environment. The world’s human
Edward Osborne Wilson was as priceless while we population has risen from less
left blind in one eye after a learn to use it and than 1 billion in 1800 to more than
fishing accident aged seven, come to understand 7 billion, and is expected to reach
and switched interests from what it means nearly 10 billion by 2050. As the
birdwatching to insects. He to humanity. population grows, so do other
discovered the first colony of threats to biodiversity: increasing
fire ants in the US when he Edward O. Wilson numbers of invasive species are
was only 13, and later spread through trade and travel;
attended the University of Water pollution is caused mainly urban development and resource
Alabama and Harvard. by sewage or by chemicals extraction destroy habitats; more
Wilson’s work has focused absorbed into water as it flows pollution is created; and land is
primarily on ants but also off agricultural land. This pollution overharvested. The impacts of
extends to the study of reduces oxygen levels in water, human population growth will be
isolated ecosystems, known making survival more difficult for difficult to limit, as ever more
as “island biogeography.” A some species, particularly when people rely on food and shelter to
leading environmentalist, combined with water temperatures survive, and demand ever more
he has spearheaded efforts that have risen due to climate goods in an increasingly global
to preserve biodiversity and change. Freshwater streams used consumer society.
educate people about it. He by certain species of spawning
has been awarded over 150 fish, for example, can be made Upsetting the balance
prizes, including the National uninhabitable by pollution. Population growth also drives
Medal for Science, the Cosmos overharvesting, the final human-
Prize, and two Pulitzer Prizes Some organisms can absorb a made threat to biodiversity in the
for nonfiction, and was named substance, such as an agricultural HIPPO acronym. Found in forestry,
one of the century’s leading chemical, more quickly than they livestock grazing, and commercial
environmentalists by Time can excrete it, in a process known agriculture, overharvesting can
and Audubon magazine. as bioaccumulation. Initial, low also arise from targeted hunting,
concentrations of chemicals may gathering, and fishing, as well as
Key works not be a problem. However, as those unintentional harvesting, such
chemicals accumulate through the as fish discarded from catches.
1984 Biophilia food chain—from phytoplankton to
1998 Consilience: The Unity fish to mammal, for example—they
of Knowledge can reach levels that cause birth
2014 The Meaning of Human defects and disrupt hormone levels
Existence and immune systems.

Poaching, forest clearance, and
other human activities have largely
contributed to the status of the African
western lowland gorilla as a “critically
endangered” species.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

THE ORDERING OF THE NATURAL WORLD 95

The building of railways across the
US was accompanied by hunters hired
to decimate the buffalo population that
had sustained Native American tribes.
By the end of the 19th century, only a
small number of wild buffalo survived.

When the rate of harvest exceeds pollution and climate change. More against natural disasters and
the rate of replenishment through than 80 per cent of the species on human-made shocks, including
either reproduction or human the IUCN’s Red List are affected by climate change, and provide
activities such as tree planting, more than one of the five major recreational, medicinal, and
the harvest is not sustainable, biodiversity threats. biological resources.
and without regulation could result
in the extinction or extirpation Biodiversity maintains the Although the threats to
of species. health of the ecosystems of the biodiversity from human activity
planet. Ecosystems are a delicate are serious, ways to protect it
A study of the IUCN’s Red List balance of living creatures, both are being developed. Foremost
in 2016 showed that 72 per cent plant and animal, as well as the is a “sustainable” approach to
of species listed as threatened or soil, air, and water in which they harvesting and agriculture that
near-threatened are harvested at live. Healthy ecosystems provide allows species—such as fish, trees,
a rate that means their numbers resources that sustain human and or crops—to be maintained at a
cannot be balanced by natural all other life, improve resilience stable level and even increased
reproduction or regrowth. Some over time. Official protected status
62 per cent of species are at risk Anthropogenic biomes for areas of land, water, and ice
from agricultural activity alone, can help sustain threatened
such as livestock farming, tree The biosphere—all the areas of species, while national and
felling, and the production of Earth and its atmosphere that international agreements and
crops for food, fuel, fibres, and contain living things—consists negotiations can mitigate the
animal fodder. of biomes, which are large impact of both legal and illegal
ecosystems based on a specific trade, such as poaching. Public
Protecting biodiversity environment, such as desert or education also helps people to
In reality, the five HIPPO threats tropical rainforest. The impact better understand their potential
identified by Wilson are interrelated, of human actions on biodiversity impacts on biodiversity and how
and there is generally no single and the consequent reshaping to protect it for future generations. ■
reason why any particular species of much of the planet have led
is endangered. Agricultural ecologists to reassess biomes grouped into six main
development, for example, can and suggest that a designation categories: dense settlements;
not only destroy a habitat, but can of anthropogenic (manmade) villages; croplands; rangeland;
also releases greenhouse gases into biomes is now necessary. forested; and wildlands.
the atmosphere, contributing to air Anthropogenic biomes are
Unlike other biomes, which
can range across continents,
anthropogenic biomes are a
mosaic of pockets over Earth’s
surface. According to ecologists,
more than 75 per cent of Earth’s
ice-free land has been affected
by at least some form of human
activity, particularly in dense
settlements (urban areas), which
account for over half the world’s
population, and villages (dense
agricultural settlements).

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

96

OWAPMEEANASIRNSEGEINPXHTTAIHNSECETOIOFN

BIODIVERSITY HOTSPOTS

IN CONTEXT A biodiversity hotspot is an and increasing challenge of mass
area with an unusually extinctions of species caused by
KEY FIGURE high concentration of the destruction of premium habitats,
Norman Myers (1934–) animal and plant species. The term Myers argued that priorities had
was coined in 1988 by Norman to be set to establish where to
BEFORE Myers, a British conservationist, concentrate resources to conserve
1950 Theodosius Dobzhansky to describe areas that are both as many lifeforms as possible.
studies plant diversity in biologically rich and deeply
the tropics. threatened. Facing the huge Defining hotspots
Initially, Myers identified ten
AFTER The lush hillsides and forests of hotspots crucial for conserving
2000 Myers and collaborators Arunachal Pradesh, India, are part plant species that were endemic
reevaluate the list of hotspots of the Indo-Burma biodiversity hotspot. (did not grow anywhere else on
and add several new ones, The area contains some 40 per cent Earth). By 2000, he had refined the
bringing the total to 25. of India’s animal and plant species. concept to focus attention on

2003 An article in American
Scientist criticizes the
concentration of conservation
effort on hotspots, saying that
this neglects less species-rich
but still important “coldspots”.

2011 A team of researchers
confirm the forests of east
Australia as the 35th hotspot.

2016 The North American
coastal plain is recognized
as meeting the criteria for a
global biodiversity hotspot—
and becomes the 36th.

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS 97

ORDERING THE NATURAL WORLD

See also: Human activity and biodiversity 92–95 ■ The ecosystem 134–137
■ Deforestation 254–259 ■ Sustainable Biosphere Initiative 322–323

Our welfare is intimately looks like an antelope; it was seen Norman Myers
tied up with the welfare of for the first time in 1992, in the
wildlife … by saving the lives Annamite Mountains of Vietnam. Myers was born in 1934
of wild species, we may be The endangered Irrawaddy dolphin and grew up in the north of
is found along the coastlines of England. He studied at the
saving our own. Southeast Asia and the islands University of Oxford before
Norman Myers of Indonesia. Other rare animals moving to Kenya, where he
include Eld’s deer, the fishing cat, worked as a government
regions that fulfilled two criteria: and the giant ibis. administrator and teacher.
the area must contain at least During the 1970s, Myers
1,500 vascular plants (plants with Protective measures studied at the University of
roots, stems, and leaves) that were Conservation agencies agree on California, Berkeley, where his
endemic, and it must have lost at targets for every hotspot. They list interest in the environment
least 70 percent of its primary species that are threatened and grew. He raised concerns
vegetation (the plants that originally make plans to conserve and manage about deforestation for cattle
grew in the area). Conservation those areas with suitable habitat ranching, describing it as the
International, an environmental and viable populations of target “hamburger connection.”
agency that uses Myers’ concept to plants and animals. Sites are ranked
guide its efforts, now lists 36 such according to how vulnerable and Myers raised the concept
regions. Although they represent irreplaceable they are. of biodiversity hotspots in
only 2.3 percent of Earth’s land the article “Threatened
surface, they are home to nearly Myers’ two criteria have been Biotas: ‘Hotspots’ in Tropical
60 percent of the planet’s plant, criticized by those who say they do Forests,” published in The
amphibian, reptile, mammal, and not take account of changing land Environmentalist in 1988.
bird species—and a high use in regions where less than 70 In his first book, Ultimate
proportion of these species live only percent of good habitat has been Security: The Environmental
in their respective hotspot. destroyed. The Amazon rain forest, Basis of Political Stability, he
for example, is not within a hotspot argued that environmental
Most hotspots lie in the tropics but the forest is being cleared faster problems lead to social and
or subtropics. The one facing the than anywhere else on Earth. ■ political crises. In 2007, Time
highest threat level is the Indo- magazine hailed Myers as a
Burma area in Southeast Asia. We are into the opening Hero of the Environment.
Only 5 percent of the original stages of a human-caused
habitat remains, but its rivers, biotic holocaust—a wholesale Key works
wetlands, and forests are vital for elimination of species—that
the conservation of mammals, 1988 “Threatened Biotas:
birds, freshwater turtles, and fish. could leave the planet Hotspots in Tropical Forests”
Animals unique to this area impoverished for at least 1993 Ultimate Security: The
include the saola, a forest-dwelling Environmental Basis of
mammal that is related to cattle but five million years. Political Stability
Norman Myers

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

OTHFELIVFAERI