An Incomplete Education - 3,684 Things You Should Have Learned but Probably Didn't

"bottom," and "top"; or from positing the existen
quarks. Quarks bond with other quarks in such sta
(two up quarks and a down quark), neutrons (two d
mesons, baryons, kaons, and so on(s)—all the oth
except leptons (a category that includes electrons,
are themselves so "elementary" as not to be able to
spite the whimsicality (the word itself is borro
Finnegans Wake, "Three quarks for Muster Mark
squawking of birds, their excrement, or both), qu
wallop. They imply that nature is three-sided, and
as time/space, mind/body, and either/or miss the p
one hand, building blocks of the universe on the o
at its most ambitious—also its coyest.

Symbiosis

The perfect relationship—assuming you're not
that interested in relating to whomever it is you
chosen to settle down with. Take, for instance, t
case of the rhinoceros and the yellow tickbird. T
tickbird dines on parasites infesting the rhinocer
horny skin; the rhinoceros itches less and is warn
of danger when the tickbird, sharp-eyed and skitti
abandons him for the nearest tree. Or the liche
that exemplary union of alga, which brings hom
the bacon (it knows how to photosynthesize), a
fungus, which keeps the house (it stores moistu
the alga needs and scoops out the rock they're livi
on to make a bungalow). In such classic instances
symbiosis ("life together"), both parties benefit bu
compensating for the other's shortcomings, rathe
Although it's tempting to apply the word to, say,
worked out nightly in the apartment down the
when you do so. The sadist and the masochist com
but they're deriving too much the same benefit
their joint undertaking to qualify as a bona-fide sy
saved for arrangements between partners with wid

Synapse

It's the junction—a microscopic gap, actually—of
nerve cells. And there are loads of them: An avera

SCIENCE 527

nce of mirror-image, or anti-,
ndard combinations as protons
down quarks and an up quark),
her subatomic particles, in fact,
muons, and neutrinos), which
o be further broken down. D e ­
owed from a song in Joyce's
k," where it may refer to the
uarks pack a mean intellectual
that such dualist constructions
point. Specks of infinity on the
other, quarks represent science

all
u've
the
The
ros'
ned

sh,
en,
me
and
ure
ing
s of
ut in very different ways, each
er than duplicating his talents.
the S ôc M relationship being
hall, you weaken its meaning
mplement each other, all right,
t—sexual gratification—from
ymbiosis, a label that should be
dely divergent priorities.

f two neighboring neurons, or
age neuron in the human brain

5o8 AN I N C O M P L E T

has somewhere between one
neurons, some of which are re
ble for moving, and some of
When a nerve impulse reache
nerve cell, it's given a nudge a
Some chemicals enhance, othe
ational drugs. The adjacent ne
itself and relaying the message
ing it the cold shoulder. Cau
place, at most a transaction. It
less a good synonym for wha
going off over somebody's hea

Synergy

Like Gestalt (see page 456), a
parts manifesto. But at least t
ogy you can understand: the
scientific, synergy refers, in b
combined physiological clou
booze and barbiturates, inges
tally than can be predicted b
own. From biology, it's a sho
that, by merging with the like
ket share in excess of their tw

E EDUCATION

thousand and ten thousand synapses with nearby
esponsible for thinking, some of which are responsi­
f which are, for better or for worse, simply blank.
es the synapse, there to jump across to the adjacent
along by an electrically triggered squirt of a chemical.
ers inhibit; ditto painkillers, tranquilizers, and recre­
erve cell reacts accordingly, either getting all excited
e to a muscle, a gland, or yet a third nerve cell, or giv­
tion when using the word: A synapse is properly a
t is not in itself a full-scale neural event, and it is even
at is portrayed in comic books as a little lightbulb
ad.

another the-whole-is-greater-than-the-sum-of-its-
this one is backed up by lab reports and an etymol­
Greek syn- + ergos, "together working." A t its most
biology, to the relationship between "agents" whose
ut outweighs the sum of their individual jabs; thus
sted together, will knock you out faster and more to­
by adding up what each of them does to you on its
ort step to the boardroom, where executives decide
e-minded types across town, they can pull in a mar­
wo individual ones put together.

Valence

In chemistry, a measure of the combining power
of a specific element, equal to the number of dif­
ferent chemical bonds one atom of that element
can form at any given time. All atoms feel most
secure when they have a complete outermost
electron shell, and they'll go to great lengths to
achieve one, borrowing elements from or sharing
them with other atoms. For this reason neon,
with an outer shell that's full-up at birth, is
highly unreactive—so chemically aloof, in fact,

that, along with helium and argon (among others
"noble gases." Carbon, by contrast, with an outer
half filled, is a born joiner and an unabashed swi
more than a single relationship to feel safe and pro
sult of this capacity for interaction that you hear so
istry circles. A s for your valence, broadly spe
tendency—to interact with the others out there. J
to go to bed with them.

Keeping Up with

In the second century a.d., Ptolemy, a Greek work
codified all ancient astronomical beliefs and ma
ment: The earth was the center of the universe, aro
ets, and the stars all revolved, and beyond the orbit
empyrean, the place where angels and immorta
mathematical and highly persuasive, the Ptolemaic
tually all educated Europeans until Copernicus' trea
Heavenly Spheres (published posthumously in 15
from nestling cozily at the center of things, it was
revolving, a theory that was soon to be embroidered
Brahe (see page 567), Kepler, Galileo, and Newto
spirits. Enter uncertainty, relativity, quarks, leptons
forces, the Big Bang, and the search for our cosmic
contributor James Trefil.

Since the late 1920s, we've known that other ga
our own. The obvious explanation for this is th
is expanding. Because every expansion has to start
that if we reverse the expansion and follow the gala
tune of some fifteen billion years, there will come
ter in the universe is crammed into a very tiny s
universe from a single infinitely dense point of m
Bang.

Astrophysicists tend to dislike obvious explana
throughout the Fifties and Sixties, there were all so
to explain expansion without the Big Bang scenari

SCIENCE

s), it's been dubbed one of the
r shell of eight electrons only
inger, almost always requiring
ovided for. It's largely as a re­
o much about carbon in chem­
eaking it's your capacity—or
ust remember, you don't have

Cosmology

king out of Alexandria, Egypt,
ade a momentous pronounce­
ound which the sun, the plan­
of the most distant star lay the
l spirits dwelled. Rigorously
c system was accepted by vir­
atise On the Revolution of the
543) broke the news that, far
s the earth that was doing the
d and enlarged upon by Tycho
on. Exit angels and immortal
s, gluons, the strong and weak
c roots. Here, with an update:

alaxies are moving away from
hat the universe as a whole
t somewhere, it's also obvious
axies backward in time, to the
a point at which all the mat­
space. The appearance of the
matter is what we call the Big

ations like this, which is why,
orts of theories that attempted
io. But new evidence came in,

AN I N C O M P L E T E

the
tod

T
phy
you
ter
a ti
also
ato
whe
wer
erg

W
two
He
you
eno
elec
of m
and
this

The Ptolemaic concept of the universe. T

has

stei

rela

cha

into

con

sult

Con

thro

bro

coll

par

A twentieth-century view of the solar system. crea
I

exp

will change form and exotic ne

energy. But there's one other

forces—the way bits of matter

E EDUCATION

se alternate theories bit the dust, one by one, and
day hardly anyone disputes the Big Bang.
T h e thing about the Big Bang as far as modern
ysics is concerned is that when the universe was
unger, it must have been hotter. Compressing mat­

always makes it heat up (try touching the barrel of
ire pump after it's been used). Higher temperatures
o mean that the building blocks of matter, such as
ms, move faster and collide more violendy. Thus,
en the universe was younger, its constituent parts
re bumping into each other with much higher en­
gy than they do in our own relatively frigid era.
When matter is subjected to high temperatures,
o important things happen. First, it changes form.
at an ice cube and you get water; heat the water and
u get steam. If you heat a collection of atoms
ough, the collision will become so violent that their
ctrons will be torn loose and you'll have a new form
matter—a collection of negatively charged electrons
d positively charged nuclei. The sun is made up of
s sort of matter.

The second important temperature-induced change
s to do with the creation of new particles via Ein­
in's famous formula, E = mc2. T h e theory of
ativity tells us that matter and energy are inter­
angeable—given enough of one, you can convert it
o the other. Thus, when a bit of uranium nucleus is
nverted into energy in a nuclear reactor, the end re­
t is sufficient electrical current to run your house.
nversely, every day, in giant particle accelerators
oughout the world protons and electrons are
ought up to almost the speed of light and allowed to
lide with a target. The result: The energy of the
ticle is converted into mass and new particles are
ated in the collision.
n this early, high-temperature universe, then, we
pect two things to happen: Existing forms of matter
ew forms of matter will be created from the available

result we might also expect: that the fundamental
r interact with one another—will also change.

The Early Universe

One way of measuring the extent of our knowledg
how close to the beginning we can get in our descrip
it. In the 1920s, for example, we knew enough abou
million years of creation. By the Fifties, the develo
allowed us to come within three minutes. Today, th
elementary particles, we can get to within a fractio
small we need a different way of writing numbers to
time between 10"36 (that's a decimal point followed b
and 10"43 (forty-two zeros and a one) seconds after t
hurdle remains before we get to the moment of crea

The best way to picture the evolution of the uni
highly compressed steam. If you let it go, it will e
so. When it cools to 212°F it will condense into d
ues to expand and cool it will reach another cri
which point the water will freeze into ice. The sa
universe as would happen with the steam, except
respond to condensation and freezing are both mo
plicated.

Although a few intrepid theorists have speculated
of matter that eventually became the universe cam
firm scientific opinion on this subject; right now t
our knowledge. With regard to the first 10"43 secon
elapsed before the first major "freezing"—we're in a
there is no generally accepted theory that describe
that existed then, we can still make out some of its s
was a tremendous simplicity. Instead of the large nu
in matter today, there was just one kind—the so ca
the four basic interactions (more on this later), the
ter to interact. Everything was as economical and
been downhill ever since.

A t 1 0 - 4 3 seconds, the first "freezing" occurred.
cles appeared—one group similar to the electro
photon (the "particle" which makes up visible li
first appeared at this time as well. T h e force o f gr
from the other forces. During the period from thi
onds, the universe may or may not have conform
grand unification theory ( G U T ) . This theory,
Seventies, is being subjected to intensive experim
on it later, too.)

During freezings at 10"36 and 1 0 1 2 seconds, resp

SCIENCE

ge about the universe is to ask
ption of the events that formed
ut atoms to get to within half a
opment of nuclear physics had
hanks to our understanding of
on of a second—a fraction so

describe it. We can talk about
by thirty-five zeros and a one)
he Big Bang. In fact, only one
ation itself.
verse is to think of a cloud of
expand, cooling off as it does
droplets of water. If it contin­
tical temperature—32°F—at
ame thing happened with the
that the transitions that cor­
ore numerous and more com­

d on how the initial collection
me into existence, there is no
he question is simply beyond
nds of the universe—the time
a little better shape. Although
es matter at the temperatures
salient features. Most striking
umber of basic particles we see
alled superparticle. Instead of
ere was only one way for mat­

as elegant as it could be. It's

Two broad classes of parti­
on, the other similar to the
ight); quarks (see page 506)
avity became distinguishable
is freezing down to 10~36 sec­
med to something called the
first developed in the m i d -
mentation right now. (More

pectively, the universe became

512 AN I N C O M P L E T E

steadily more differentiated a
of a millisecond), the free q
densed into the elementary p
we know it. At three minutes
form the nuclei of atoms. F
major transition occurred. Th
clei to form simple atoms. In
of matter occurred as soon a
which the interparticle collisi
fragile new structure.

The fifteen billion years tha
of galaxies and stars and the d
chemical elements heavier tha
carbon in your D N A , were ma
to the interstellar medium, wh
Still, from the point of view o
in the history of the universe
fact, it takes longer to describ
dergo the actions described.

What Matter Is Made O

The best analogy for how we
an onion. We peel off one lay
that there is yet another to wo
1805, when British chemist J
of matter. He showed that the
is made up of only a few differ
type of atom. In the early tw
when the structure of the atom
it was argued, were made up
tons and neutrons in the nucle
of the atom would become mo
plicity seemed to be clouded
types of particles inside the nu
disappeared too quickly to be
accelerators.

In the mid-1960s, yet anoth
myriad elementary particles ar
basic entities called quarks. Qu
they're the Elmer's that keeps

E EDUCATION

and more complex. At around 10"5 seconds (a tenth
quarks that had been roaming the universe con­
particles that are the building blocks of matter as
s, these elementary particles started to collect to
inally, at five hundred thousand years, the final
he first electrons attached themselves to those nu­

each of these cases, the transition to a new form
as the temperature had dropped to the point at
ions no longer had sufficient energy to disrupt the

at have elapsed since then have seen the formation
development of life. During this period, all of the
an helium, including the iron in your blood and the
ade in stars that later died, returning their contents
here they were taken into the nascent solar system.
of fundamental physics, all of the interesting events
were over by the time it was a few minutes old. In
be what happened than it took the universe to un­

Of

are coming to understand matter is the peeling of
yer and penetrate to a deeper one, only to discover
ork on. The first layer was peeled off our onion in
John Dalton published the modern atomic theory
e enormous variety of substances that surround us
rent chemical elements, each of which has its own
wentieth century the second layer was peeled off
m was revealed. All of the different kinds of atoms,

of only three kinds of elementary particles—pro­
eus and electrons orbiting the nucleus; this picture
ore or less standard. For a while, its inherent sim­

when it was found that there were not just two
ucleus, but hundreds. Most of these appeared and
seen, but they could be produced independently in

her layer was peeled off. It was pointed out that the
re actually made up of a small number of still more
uarks are held together by particles called gluons—
s the three quarks of a proton or neutron together.

Scientists believe that these particles derive from
matter called quark-gluon plasma, a primordial so
ten millionths of a second after the Big Bang. A s t
went through "hadronization," hardening into pr
turn coalesced first into nuclei, then into atoms. A
gether to form molecules, which eventually transfo
the easy chair you're sitting in. At least, that's the

The Fundamental Forces

Physics is the study of matter and motion. Thus
building blocks of matter that led to the quarks is o
half has to do with the way that matter in all stag
itself. U p until the beginning of the twentieth cen
to find only two fundamental forces in nature—the
associated with electricity and magnetism. Since th
subnuclear world have produced two more fundam
is part of our everyday experience. One of these, t
all the elementary particles together in a nucleus. T
erates in many situations in nature, the most fami
decay of some unstable nuclei and particles. Thes
Some, like electromagnetism and gravity, act over l
two nuclear forces, act only over distances about t
They also differ markedly in strength, with the str
followed by the electromagnetic, weak, and gravita

Despite these apparent differences among the
physics over the last few decades have been made
the differences are only apparent, and that the forc
are important historical precedents for this view. I
in the seventeenth century, when he showed that
backyard, causes an apple to fall to the ground als
in their orbits. In so doing, he reversed two millen
ing which scientists had seen no resemblance betw
ity. Yet Newton's Theory of Universal Gravitation,
of both planets and apples to a mutual attraction
possessing mass, says that despite apparent differen
tom, the same. We say that Newton unified the
cause of the term "gravitational field," we say t
example of a "unified field theory."

In 1968, Steven Weinberg (then at M I T ) took
unification of the forces when he theorized that

SCIENCE 513

m an even more basic form of
oup that made up the universe
things cooled down, this liquid
otons and neutrons, which in
After that, the atoms came to­
ormed into you, this book, and
theory.

the quest for the fundamental
only half the picture. The other
ges behaves, i.e., interacts with
ntury, physicists had been able
e force of gravity and the force
hen, studies of the nuclear and
mental forces, neither of which
the strong force, is what holds
The other, the weak force, op­
liar being the slow radioactive
se four forces are a varied lot.
long distances. Others, like the
the width of a nucleus or less.
rong being the most powerful,
ational forces.

forces, the great advances in
e by theorists who believe that
ces are actually identical. There
Isaac Newton gave us the first

the same force which, in your
so holds the moon and planets
nnia of Western thought, dur­
ween earthly and celestial grav­
, which attributes the motions
that exists between all objects
nces, the two forces are, at bot­
two forces of gravity and, be­
that Newtonian gravity is an

an important step toward the
the weak and electrical forces

AN I N C O M P L E T E

were unified (i.e., essentially
them were due more to the pr
thing fundamental to their na
basic interactions in nature fro
this particular unified theory
everyone.

The new idea that made t
principle. In essence, this prin
be one in which it is not signi
definitions of things. For exa
of gravity is one in which the
a cliff is the same whether y
winding path. Theories like t
rates the gauge principle, are

Gauge theories and unific
shown the way, a further un
grand unification theory me
and the strong and weak nucle
same. In addition to allowing
universe, the G U T predicts th
that the proton, hitherto thou
nucleus, actually decays. And
means no more atoms, no m
more K F C , no more anything

The good news—for mos
doom—is that after almost th
cayed. Until that happens, an

Gravity: Odd Man Out

Given this history, it would se
is use the same techniques to
mate theory, in which all forc
roof. Such a theory would be

Unfortunately, this is one o
concept of gravity centers on
concept of force used in this t
to describe the other three
theoretical physics these days

T h e first thing to realize i

E EDUCATION

y identical), and that apparent differences between
resent low temperature of the universe than to any­
atures. The result was a reduction in the number of
om four to three. Since 1968, enough predictions of
y have been confirmed that it is now accepted by

this particular advance possible is called the gauge
nciple states that the correct theory of nature must
ificant if different observers come up with different
mple, the principle suggests that the correct theory
amount of energy you expend getting to the top of
you go straight up its side or take a more gradual,
that of the electroweak interaction, which incorpo­
said to be gauge theories.
cation go hand in hand, and once Weinberg had
nification was not long in coming. This was the
entioned above. In the G U T , the electromagnetic
ear forces are all considered to be fundamentally the
g us to retrace the history of the beginnings of the
he end of it. That is, most G U T s hinge on the idea
ught to be the absolutely stable building block of the
d if one proton can decay, all of them can—that
ore molecules, no more D N A , no more C N N , no
g.
st laypeople, if not for scientists and prophets of
hree decades of research, not a single proton has de­
y proof of a grand unification theory is still elusive.

t

eem that the next step is obvious. All we have to do
bring gravity into the fold and we'll have the ulti­
ces of nature are brought together under the same
called the Theory of Everything (TOE).
of those easier-said-than-done things. Our current
n Einstein's General Theory of Relativity, and the
theory is radically different from the concepts used
forces. To understand the frontier problem in
s, then, we have to know something about relativity.
is that there are actually two theories of relativity.

The simplest, called the special theory, was publi
ory of gravitation, but most of the other effects as
corporated into it. The equivalence of mass an
(which stated that a twin who went on a long s
would be much younger when he returned than h
and the increase of mass with speed were all pred
verified experimentally; in fact, every time an a
particles, every time a reactor produces a kilowatt
fied anew.

The general theory was published in 1916. It is
it was accepted with only a few experimental tests
bending of starlight as it passes the edge of the sun

Both theories are based on a single principle,
the principle of relativity. It states that any two ob
laws of physics in action, regardless of their relativ
ferent the picture may look to the two of them. T
in that the two observers can't be accelerating, whe
for any observers, accelerating or not. Since gravity
be treated only in the context of the general theor

To grasp the picture of the gravitational intera
other analogy. Imagine a rubber sheet held taut at
most often used to discuss Einstein's curved, four-
tinuum.) If we drop a heavy weight on the sheet, th
ing a depression in the area of the weight. If we sh
it could well become trapped in this depression,
cling round and round the heavier weight. In gen
relativity, a large object (such as the earth) distorts
fabric of space and time in just the same way that
heavy weight distorts the sheet. Other objects (suc
the moon) react to this distortion by going into o
The important point about this view of gravity is
it is purely geometrical—it does not involve any
namic concept of force. It's this difference betw
gravity and the other fundamental forces that ma
the development of a truly unified field theory so
ficult.

There's one more thing to say about relativity.
only does it not imply that "everything is relative,
fact, the whole point is that, even though different
servers may see events differently, there is still a
and unchanging bedrock in nature—a bedrock m
up of the laws of physics.

SCIENCE 5Î5

shed in 1905. It is not a the­
ssociated with relativity are in­
nd energy, the twin paradox
space journey at high velocity
his brother who stayed home),
icted by this theory. It is well
accelerator delivers a burst of
t of energy, the theory is veri­

anomalous in science because
s, the most familiar being the
n.
called, appropriately enough,
bservers will discover the same
ve motion, no matter how dif­
he special theory is restricted
ereas the general theory holds
y produces acceleration, it can
y.
ction that arises we need an­
t the edges. (This is the image
-dimensional space-time con­
he sheet will deform, develop­
hoot a marble across the sheet,
cir­
neral

the
t the
ch as
orbit.
that

dy­
ween
akes

dif­

Not
," in
ob­
firm
made

CHECKING IN WITH Q

Quantum mechanics is the name given to t
scribes the behavior of matter on the atomic an
spate of books and articles, each purporting to
quires some basic change in our thinking abou
to turn to Eastern mysticism because of it, ot
sciousness is required for the world to functio
chanics demands the downfall of patriarchal so

There's no question that the world of the e
in our everyday experience, we're accustomed
changing it. We can watch a bowling ball roll a
beams bouncing off it and hitting our eyes w
world, the possibility of continuous observat
smoothly from one point to the next.

In the subatomic world, things are different.
another particle off it, and this must necessaril
way we could determine the position of a bowl
off it. In that case, its smooth, continuous, pred
place.

In the subatomic world, the act of measurem
ing rise to what is known as the Heisenberg Un
if we choose to measure one quantity (e.g., the
system itself and therefore can't be certain abo
is moving). Since an interaction is involved in
are involved in observations, physicists sometim
system. This is a reasonable statement, provid
cles, not the conscious observer, that is impo
quantum mechanics, although there are plent
suggest that it does.

That probing matter affects its form and beh
quantum mechanics. Equally bizarre: that som
but "virtual," and that the universe as we know
subatomic level.

QUANTUM MECHANICS

the theory, developed in the 1920s, which de­
nd subatomic level. It has been the subject of a
o show that accepting quantum mechanics re­
ut the world. Some authors tell us that we have
thers that it teaches that the presence of con­
on. One writer has claimed that quantum me­
ocieties.
lectron is different from our own. For starters,
d to being able to observe something without
along, confident in the knowledge that the light
won't deflect it from its path. In our everyday
tion allows us to assume that the ball moves

The only way to observe a particle is to bounce
ly disturb the original particle. It's as if the only
ling ball was by bouncing another bowling ball
dictable motion toward the pins could not take

ment changes the system being measured, giv­
ncertainty Principle. The principle tells us that
position of an electron), we inevitably alter the
out other quantities (e.g., how fast the electron
n every measurement, and since measurements
mes say that the act of observation changes the
ed you realize that it's the interaction of parti­
ortant. Consciousness has nothing to do with
y of people who misinterpret the principle to

havior is only part of the weirdness inherent in
me particles exist so briefly that they are not real
w it is based on chance and randomness at the

Hot Science: Two Tre
Revolutionize Our Wo

Make Much D

Billed as Chaos Theory
the Storyline
A Paradigm Shift
The Time Frame
Part One: That even an eens
input can make certain kinds o
simple dynamic systems—e.
heart function, the stock mar
wire. Therefore, since eensy
input are unavoidable, such sys
be considered inherentiy unpre
is, a certain amount of chaos
them. Part Two: T h a t there's
beneath the disorder; chaotic b
follows simple rules and forms
patterns. What's more, when
that behavior into mathemat
then plot the models on the c
get the kind of visuals people us
drop acid to see.

Meteorologist Edward Lorenz
ing) started tracking chaotic
terns on his computer back in th
throughout the 1970s, scientist
various fields felt the urge to s
behavior. Eventually, they star
each other. Chaos theory reall
the rest of us, though, in 198
bestselling b o o k Chaos (see
brought science to the talk-sho

SCIENCE iî7

endy Theories That May
orldview—or May Not
Difference at All

Superstring Theory

The Theory of Everything

sy change in T h e universe is composed not of subatomic
of supposedly particles that are shaped like pencil points—
.g., weather, quarks, leptons, neutrinos, etc.—but of tiny
rket—go hay­ strings tied together at the ends to form loops.
y changes in These strings exist in a ten-dimensional uni­
stems have to verse that, sometime before the Big Bang,
edictable; that cracked into two pieces, a four-dimensional
universe (ours; that's three dimensions plus
is built into time) and a six-dimensional universe that
order lurking condensed and curled up into a ball so small
behavior itself we haven't been able to see it. W h a t physicists
s recognizable have been thinking of as subatomic particles
you translate are actually vibrations of the strings, like notes
tical models, played on a violin. T h e universe, in fact, could
computer, you be compared to a symphony of superstrings
sed to have to vibrating at gazillions of different frequencies.

z (see follow­ A n early, go-nowhere version o f string the­
weather pat­ ory—which proposed that quarks were not
he 1960s, and particles but the ends of pieces of string—first
ts working in made the rounds in 1968, and a few mathe­
study random matically inclined physicists continued to play
rted talking to with the idea of strings throughout the 1970s.
y took off for Superstring theory, with its ten dimensions,
87, when the supersymmetry (see following), and promises
e following) of imminent glory came along in 1984 and
ow circuit. kept physicists on the edge of their seats for
the next few years. But by the early 1990s,
there were five different versions o f string the­
ory and it was clear that there were still a few
technical problems that might take, oh, an­
other ten, twenty, or maybe fifty years to work
out.

The Big AN I N C O M P L E T E
Breakthrough
Chaos Theory

Forced scientists to trash cherish
an ultimately predictable, clock
and get in touch with the real, Ba
ley world. H a s given everyone a
look at data; suddenly, a systems
as telltale and worthy of study as i
abiding behavior.

The Box-Office Suits the Zeitgeist. Seems true to
Appeal know it. Allows ordinary people
about their aptitude for science s
they recognize the word "chaos
forting, implies that even sniper
rorist bombings, rapidly muta

E EDUCATION

hed notion of Superstring and M Theory
klike universe
arnum & Bai­ T h e first theory that manages to link gravity
a new way to with the three other fundamental forces
(strong, weak, and electromagnetic), thereby
glitches seem reconciling Einstein's general theory of rela­
its stable, law- tivity (which governs the big stuff: stars,
planets, galaxies) with quantum mechanics
(which governs the subatomic world). The
apparently total incompatibility of these two
bases of modern physics has been the biggest
stumbling block on the road to a Theory of
Everything and has been driving physicists
crazy for half a century. In 1995, physicist
Edward Witten got everyone excited again
when he introduced what's come to be
known as M Theory (a.k.a. the Second Su­
perstring Revolution). We won't make your
head ache with the specifics; just remember
Witten's general idea, which is that the vari­
ous versions of string theory and the appar-
endy incompatible relationships they contain
are, in fact, all connected, but they don't seem
to m e s h because they are only approximations
of some other underlying theory. Witten hy­
pothesized that the standard ten dimensions
were also an approximation and that actu­
ally there are eleven. Mathematically, many
pesky pieces of the puzzle, including grav­
ity, suddenly s e e m e d to fit. N o t everyone
cheered and jumped on the bandwagon,
however, since Witten also noted that until
more advanced mathematical tools are in­
vented, physicists will have no way of prov­
ing, disproving, or even understanding M
Theory.

o reality as we For theoretical physicists, the sheer elegance
to feel better of the theory itself, plus the possibility of ex­
plaining everything in the entire universe
since, at least, and winning a Nobel Prize. For the rest of us,
s." Also com­ apart from a vague sense of validation ("Just
s' bullets, ter­ as we thought, there's more going on in this
ating viruses,

The Critics Chaos Theory
Complain
and teenage drivers are part of
The Fans Parry order, subject to natural laws a
presumably, amenable to control

What's the big deal? All the st
linear dynamics (doesn't see
thrilling without the catchy nam
did was correct a mistaken
that the Newtonian world was
Which makes it a step in the ri
all right, but hardly a revolution

W h a t d o you m e a n , "All it d i d w
mistaken assumption .. . "? Th
assumption's been distorting sci
hundred years! You might as w
Newton did was correct a few m
sumptions about how the unive
O r "All E i n s t e i n did w a s correc
taken assumptions about energy

The Real Problem, Everyone's dying to interpret c
IfYouAskUs to suit the occasion and/or his
sonal agenda (from the Anglica
points to it as evidence that th
work-in-progress by G o d to the
itor who uses it to explain why
are wearing ballgowns this fall
are wearing leather chaps), ma
to remember what the scienti
point was.

So What Good Is It? Has lots of technological applic
predicting nuclear meltdowns, h
and stock market fluctuations
kerosene heaters, "smart" com
groovy light-show attachments
stereo systems.

SCIENCE 519

some cosmic Superstring and M Theory
nd therefore,
l. cockeyed world than what the politicians are
telling us"), pure entertainment.

tudy of non­ "Vibrating strings," h o w ridiculous. T h e r e
em quite as aren't any strings in nature. Besides, this
me, does it?) theory is so complicated that it can never be
tested, even mathematically. And any the­
assumption: ory that can't be tested is pure sci-fi; it be­
predictable. longs on the trash heap.
ght direction
nary idea.

was correct a O h really? W h a t about D N A , that's a string,
hat mistaken isn't it? A n d in case you've forgotten, N e w ­
ience for two ton couldn't test his universal law of gravita­
well say, "All tion when he first discovered it, either,
mistaken as­ seventeenth-century mathematics was too
rse worked." primitive to handle it. S o he went home and
ct some mis­ invented calculus. You'll be laughing on the
y and mass." other side of your face when somebody
comes up with a math sophisticated enough
to confirm superstring theory—maybe some­
time in the next century.

chaos theory It's too complex and bizarre even for most
s or her per­ physicists to wrap their minds around. So
n priest who who could possibly direct the movie version?
he world is a
e fashion ed­
some people
while others
aking it hard
ists' original

cations, from None whatsoever, unless you believe it really
heart attacks, is the fabled Theory of Everything, the Holy
Grail of physics—a science whose goal, after
to making all, is not to make better kerosene heaters
mputers, and but, as Einstein put it, "to know the mind o f
God."
s for home

52Q AN I N C O M P L E T E

Celebrities in the Chaos Theory
Field
Mitchell Feigenbaum (a.ka. "
Related Ideas with physicist who constructed m
Market Potential mathematics and methodology
ory); Edward Lorenz (meteor
gave us the Butterfly Effect, an
will get to eventually); B e n o i t
(mathematician who gave us fr
James Yorke (mathematician wh
term "chaos"); J a m e s G l e i c k (New
reporter who wrote the best
Chaos: Making a New Science, w
much publicity that a lot of peop
Gleick invented the theory).

The Butterfly Effect: E d w a r d L
observation, vis-à-vis the unpre
weather, that a butterfly flappin
Brazil today can cause a torna
three weeks from now. T h i s i
basic chaos-theory principle of "
sitivity to initial conditions," i.e.,
alteration in input can cause w
in outcome.
Strange Attractor: A computer
up of points of data that form a
sual model of the chaotic behav
ticular dynamic system. T h e v
the behavior seems compelled
patterns hints at some structure
ing the apparent chaos. A stra
could illustrate, for example, th
growth of giraffes in Kenya or a
of traffic jams on the Santa Mon
expressing the results in stran
that could look like anything
nuts to looped-over ribbons to
of eyes.

E EDUCATION

"Mr. Chaos," Superstring Theory
much of the
John Schwarz and Michael Green (early,
of chaos the­ preserving proponents of various string
rologist who and superstring theories, see following);
nd whom we David Gross, Jeffrey Harvey, Emil Mar-
tinec, and Ryan Rohm (team of Princeton
Mandelbrot physicists responsible for a promising ver­
ractals, ditto); sion of superstring theory; hence, their nick­
ho gave us the name, the Princeton String Quartet);
w York Times Edward Witten (genius leader of the super-
tselling book string-theory pack, frequendy hailed as the
which got so new Einstein).
ple now think

Lorenz's 1960 Hyperspace: Higher-dimensional space. String
edictability of theory, for instance, posits a universe with
ng its wings in twenty-six dimensions, sixteen of which
ado in Texas are rolled up, geometrically, to leave the
illustrates the ten of superstring theory. All sorts of bizarre
"extreme sen­ things exist in hyperspace, from wormholes
, even a slight (tears in the fabric of space) to parallel
ild variations universes.
Flatland: E d w i n Abbott's 1 8 8 4 social satire
image made about the narrow-minded inhabitants of a
pattern, a vi­ two-dimensional world who refuse to ac­
vior of a par­ cept the possibility of a third dimension;
very fact that the hero is Mr. Square, a Fladander who's
to form such forced to broaden his outlook when he's
e or law guid­ hurled into the third dimension by Lord
ange attractor S p h e r e . Flatland is frequently evoked by
he population proponents of superstring theory to illus­
week's worth trate their predicament.
nica Freeway,
nge attractors
from d o u g h ­
spooky pairs

Chaos Theory

Fractal: B e n o i t M a n d e l b r o t ' s w o
regular pattern that's self-simila
which means any part of it looks
like the whole. We like to think
broccoli florets look, each one o
like little heads of broccoli, bu
example is the coastline of Engl
we've been assured, exhibits the
and degree of twists and turns
measured in miles from a sat
inches under a magnifying glass

Complexity theory, which trie
stand how simple elements g
complex systems (e.g., how did
cells ever get together to form y
and how, contrary to the sec
thermodynamics (see Entropy,
chaos, like the chaotic soup o
universe, manages to organize
things as awesomely comple
galaxies, and planets.

SCIENCE

Superstring Theory

ord for an ir­
ar in scale—
s remarkably
k of the way
of them, just
t the classic
land, which,
e same type
whether it's
tellite or in
s.

es to under­ Supersymmetry, the perfect mathematical
give rise to symmetry of higher-dimensional space. Yet
d your brain another umbrella step toward the unifi­
your brain?) cation of absolutely everything, supersym­
cond law of metry would allow for the interchange,
, page 556), impossible in quantum theory, of bosons,
of the early the subatomic packets in which forces
e itself into travel (think of them as energy particles)
x as stars, and fermions, the parts of atoms (think of
them as matter particles). In supersymme­
try, a boson could be mathematically "spun"
along a dimensional axis in such a way as to
turn into a corresponding, though strictly
hypothetical, fermion, and vice versa; for
instance, a photon would turn into some­
thing called a photino and an electron into
a "selectron." T h e generic name for these
alter egos of particles is—and here physi­
cists' imaginations seem, for once, to have
failed them—"sparticles." According to the
mythology of supersymmetry, particles and
their sparticles were once identical, in the
halcyon nanoseconds immediately follow­
ing the Big Bang.

522 AN I N C O M P L E T E

Riding Herd

They're an ornery lot and
wandering off into the ch
expectedly with a brood of w
back in Biology 101 that once
back on them again for a mi
would turn out to be wrong, o
Here contributors Judith Sto
meanest subjects to the groun
sory and definitely fleeting—

ALL

"Descended from monkeys?"
after hearing about Darwin's
hope it isn't true! But if it is, l

Well, the skeleton's been ou
anthropologists have a fairly c
ily tree, based on fossil remain
back to a tiny, shrewlike creat
appeared abruptly and myster
diversified, tree dwellers dev
hands that could grasp, and b
This ape line seems to have
group stayed apes, the other e

About 15 million years ag
way to grassy savanna. Those
became the family Hominida
the only remaining member. A
ble ancestors following, inclu
hominid fossil found to date
2001); the controversial, Hob
2003); Turkana Boy (a nearly
and, of course, Lucy, the 3.2-t
fossils, who achieved celebrity

Trouble is, the hominid fa
dignified elm and more like a
directions. That's because a l
ogy—the study of ancient life

E EDUCATION

d on the Life Sciences

skittish to boot, always fighting among themselves,
haparral, grazing near precipices, or popping up un­
wacky hybrid offspring in tow. Nobody warned you
e you took them on, you'd never be able to turn your
inute. (Or that everything you'd learn about them
or at least outdated, just when you needed it most.)
one and Karen Houppert wrestle a few of bio-sci's
nd, in an effort to restore some sense—possibly illu­
—of mastery and control.

IN T H E FAMILY

" the Bishop of Worcester's wife is said to have cried
startling new theory of evolution. "My dear, let us
let us pray it doesn't become widely known!"
ut of the closet for almost 150 years now, and today

clear, though unfinished, picture of the human fam­
ns. Like all mammals, we ultimately trace our roots
ture that inherited the earth after the dinosaurs dis­
riously 65 million years ago. As the shrew's progeny
veloped such dandy gimmicks as binocular vision,
brains efficient enough to handle all that swinging.
forked between 10 and 4.5 million years ago; one
eventually became us.
go, the planet's climate cooled; steamy forests gave
tree dwellers who came down for a look eventually
ae, of which our subspecies, Homo sapiens sapiens, is
A hominid family album would feature the venera­
uding Tournai, the oldest—and most human-like—
(a nearly complete cranium discovered in Chad in
bbit-like L B 1 (found on an Indonesian island in
y complete skeleton discovered in Kenya in 1984);
to-3.6-million-year-old grand dame of the hominid
y status back in 1974.
mily tree is starting to look less and less like a tall,
squat forsythia with branches shooting wildly in all
lot of scientists working in the field of paleontol­
e-forms—keep (literally) digging up new discover-

ies: new species, new genera, some of them overl
(Ten of the species listed following were not kn
What's more, the dating of the new species is con
ing scientists basing their claims on limited inform
to settle old scores. In the meantime, information
knows? By the time you read this, Fredusflintstonien

NAME: Sahelanthropus tchadensis (from Sahel, a r
Sahara Desert, where the fossils were discovered)
TIME FRAME: Lived 6 to 7 million years ago.
VITAL STATS: Apelike braincase suggests very small
cubic centimeters). But its relatively short and fl
structures above the eye sockets), and small canine
Lots of debate about whether or not it stood uprig
COMMENTS: A fossil cranium discovered by an u
2001 and later identified by Michel Brunet and
him—they think he's a male—"Tournai," which,
means "hope of life." Tournai was important for a c
discovered more than a thousand miles from the si
ontologists have been focusing most of their work.
status throw into question the age of the "missing
ancestor we share with chimps. He does bolster th
suggest that hominid evolution was way messier th
it's hard to know whether Tournai lies directly in ou
longs to a separate branch of the hominid family t
at all; critics insist that Tournai is just a female gori

SCIENCE 52J

lapping, or coming very close.
nown to exist a decade ago.)
ntroversial, with some compet­
mation and using the skeletons
n continues to trickle in. Who
nsis may have turned up.

region in Africa bordering the

l brain size (approximately 350
lat face, browridges (the bony
es are typical of later hominids.
ght.
undergraduate fossil hunter in
d associates, who nicknamed

in the local Goran language,
couple of reasons. First, he was
ites in East Africa where pale­
. Second, his age and hominid
g link"—that elusive common
he argument of scientists who
han originally thought. In fact,
ur evolutionary line or if he be­
tree. Or even if he's a hominid
illa in hominid drag. Recently,

AN I N C O M P L E T E

one of the leaders of the Tour
cused Brunet of surreptitiously

N A M E : Orrorin turenensis {orr
where the fossils were discove
T I M E FRAME: Lived c. 6 millio
VITAL STATS: Hard to say, sin
mentary arms and thigh bone
those of Homo sapiens. L i m b
Lucy's {A. afarensis, see follow
the size of a female chimpanz
was bipedal and also adapted
C O M M E N T S : Another really o
western Kenya by Brigitte Sen
lowing.

N A M E : Ardipithecus ramidus (
ramid, the word for "root"); a
Afar)
TIME FRAME: Originally dated
abba dates that species back to
VITAL STATS: Stood approxi
pounds; could walk upright,
marked by humanlike diamo
V-shaped canines of chimpanz
COMMENTS: O K , take a deep
sis and Ardipithecus ramidus, n
is a paleontologist's version o
never know what they'll find t

A. ramidus appeared first in
Asfaw came across its fossils i
initially believed that their di
then decided that it belonged
three reasons: First, it was con
ond, it lived in a rain forest, w
that the hominid's bipedal ad
habitats. Finally, because it wa
it was not actually an ancestor
common (undiscovered) ances
sarily the infamous missing lin

Then, in 2001, just when e
anatomist Brigitte Senut and

E EDUCATION

rnai expedition added fuel to this fire when he ac­
y gluing a wisdom tooth to the jawbone.

rorin, "original man ' in Tugen, the language spoken
ered)
on years ago.
nce there's not much there. (Fossils consist of frag­
es, lower jaws and teeth.) Back teeth are similar to

bones are about one and a half times bigger than
wing), which suggests that 0. turenensis was about
zee. Grooves in the femurs suggest that the species
to tree climbing, but don't hold us to that.
old possible ancestor; these fossils were found in
nut and Martin Pickford in 2001. For more, see fol­

(ardi, "ground" or "floor" in the Afar language, and
also Ardipithecus kadabba {kadabba, "progenitor" in

d at 4.4 million years, but recent analysis of A. kad­
o 5.2 to 5.8 million years ago.
mately four feet tall and weighed about eighty
but probably spent a lot of its time in the trees;
ond-shaped canine upper teeth (rather than the
zees). But generally pretty chimpy-looking.
breath. T h e competition between Orrorin turenen­
not to mention the latter's older cousin, A. kadabba,
of a barroom brawl—it's wild, it's messy, and you
to slug each other with.
n 1994, when Tim White, Gen Suwa, and Berhane
n the Middle Awash region of Ethiopia. The team
iscovery was part of the Australopithecus genus but
d in its own category. A. ramidus was important for
nsiderably older than the previous discoveries. Sec­
which threw into disarray the then-prevalent idea
daptation was a result of the expansion of savanna
as not part of the Australopithecus clan, it meant that
r of the later species, but was a "sister taxon" with a
stor. All of this meant that A. ramidus wasn't neces­
nk—but it was awfully close.
everyone was getting comfortable with A. ramidus,
d paleontologist Martin Pickford announced that

they had discovered a completely new—and olde
Orrorin turenensis, in Kenya o f all places. (Up to th
ally conducted their digs in Ethiopia.) There wasn'
thirteen fossils, including a partial femur, parts
teeth—but the age of the fossils demonstrated tha
it was the oldest on record. (At least, at that point;
Not only did the discovery rain on A. ramidus' par
nensis may have been bipedal and had a certain si
on its teeth showed that it could be a closer rela
Australopithecus. This suggested that Lucy and her
an evolutionary dead end.

As if this weren't controversial enough, a turf
rights in the area where Pickford and Senut mad
thropologist, Andrew Hill, who'd had a thing aga
uate school days at the University of London, leve
for Senut, Hill had the support of Richard Leak
family dynasty of anthropologists. (Pickford and L
history, of which we'll spare you the details.) Thing
authorities (on Leakey's suggestion) arrested Pickf
for a few days. Since then, Orrorin turenensis has b
cion and, at worst, contempt by much of the paleo

Now, another fly in the ointment: In 1997 and
sils were discovered in Ethiopia that were simila
about 5.8 million years ago) and more apelike—
A. ramidus. These were initially named Ardipithecu
tists eventually decided that these new fossils we
were likely the direct ancestor of A. ramidus. A s a
gorized as a new species in their own right: Ardi
head isn't swimming yet, there are other scientists
nensis and Sahelanthropus tchadensis are not reall
should be included in the Ardipithecus family.

N A M E : Australopithecus anamensis (anam means "l
TIME FRAME: Something like 4 million years ago.
VITAL STATS: Most definitely a biped. Still a very p
advanced, humanlike body. An interesting mix of
brain) and the genus Homo (strolling about on t
teeth).
COMMENTS: Odd history on this one. The initial
an upper left arm—was actually discovered by a H
way back in 1965. Then, except for a single mol
found until a team organized by Maeve Leakey (w

SCIENCE 5*5

er—species, which they called
hat point, anthropologists usu­
't much of this specimen left—
s of a lower jaw, and several
at if this was indeed a hominid,
; Tournai hadn't shown up yet.)
rade, but the fact that 0. ture­
ze of molars and thick enamel
ation to Homo sapiens than the
r gang may have actually been

f war erupted over excavation
de their discovery. A Yale an­
ainst Pickford since their grad­
eled the charge. Unfortunately
key, part of the famed Leakey
Leakey had their own turbulent
gs got so nasty that the Kenyan
ford and threw him into prison
been treated with at best suspi­
ontological community.
d 2001 more fragmentary fos­
ar to—but a wee bit older (at
—than the 4.4-million-year-old
us ramidus kadabba, but scien­
ere not a subspecies at all and
result, these fossils were cate­
ipithecus kadabba. A n d if your
s who claim that Orrorin ture­
ly separate genera at all, but

lake" in the Turkana language)

primitive cranium, but a more
f the chimp (big canines, little
two legs, thick enamel on its

find of A. anamensis—part o f
Harvard University expedition
lar in 1982, nothing else was
wife of Richard Leakey) made a

5*6 AN I N C O M P L E T E

number of fossil discoveries
Kanapoi region in Kenya. Int
ponents of A. anamensis that
Australopithecus afarensis (see
"branch" theory of hominid d

NAME: Australopithecus afaren

TIME FRAME: Between 3 and

VITAL STATS: Brain of about 4

with more humanlike teeth).

ably be confused with a chimp

Stood only about three or fou

COMMENTS: In 1974, in Ethi

male skeleton he dubbed Luc

amonds." Scientists figure sh

Lucy captured the imaginatio

shadowed by older fossils in t

ness; unlike many other foss

remains were found.

NAME: Australopithecus afric

TIME FRAME: Between 2 and

VITAL STATS: Similar to A. afa

bit bigger, too—between 420

than a chimp's brain and co

thinks that A. africanus was re

COMMENTS: One of the earlie

arduous seventy-three-day di

1924 in South Africa. Named

covered, this three-year-old s

was so obviously somewhere

the idea—commonly held up

origins of man.

NAME: Australopithecusgarhi
TIME FRAME: 2.5 million year
VITAL STATS: Still has a pretty
ally quite large, along with its
be a middle mark between the
you fear, we're going to explain
A. afarensis and early members
COMMENTS: Calling this on
controversial, since its existen

E EDUCATION

s in the late Eighties and early Nineties in the
terestingly enough, there are certain physical com­
seem to be closer to the Homo genus than the later
e below). Perhaps yet another argument for the
development. . .

nsis (from Afar, a region in Ethiopia)
3.9 million years ago.

400 cubic centimeters in a very apelike skull (though
Certainly walked upright, but even so could prob­

p in the dark, especially given those long hairy arms.
ur feet tall.
iopia, anthropologist Donald Johanson found a fe­
cy, after the Beatles song "Lucy in the Sky with D i ­
he was about twenty-five years old when she died.
on of journalists for a long time, until she was over­
the 1990s. Part of her appeal lies in her complete­
silized discoveries, more than 40 percent of Lucy's

canus
3 million years ago.
arensis, but with a slightly bigger body. Cranium is a
0 and 500 cubic centimeters. Though this is bigger
ould suggest some analytical skills, nobody really
eciting the Gettysburg Address.
er paleontological finds, this one was the result of an
ig by the famous anthropologist Raymond Dart in
d the Taung Child after the area where he was dis­
specimen caught the world's attention because he
between an ape and a human. He also blew apart
p until that point—that Asia was the home of the

{garhi, "surprise" in the Afar language)
rs ago
teeny brain. However,^, garhi's teeth, which are re­
humanoid humerus and femur, suggest that it could
e gracile and robust Australopithecus families (just as
n that in a moment) or even a link between its cousin
s of the Homo genus. But don't quote us on that.
e a surprise is an understatement; garhi is quite
nce throws into disarray a lot of previously held as-

sumptions about the other members of the Aust
A. africanus, which could be an evolutionary dea
from the fact that fossils of animal bones discovere
tools. This would mean that A. garhi is the first to
havior predated increases in brain size. (The olde
about 2.6 million years old, were also discovered n

NAME: Australopithecus aethiopicus
TIME FRAME: Somewhere between 2.6 and 2.3 mil
VITAL STATS: Interesting mix of the primitive and t
(410 cubic centimeters) and other parts of the skul
sis. Large, flat face with no forehead. H u g e teeth, a
ful chewing muscles suggests that this species ate g
COMMENTS: Known mostly by the "Black Skull,"
the Lake Turkana area of Kenya. Scientists genera
whether to classify this in the Australopithecus or P
clearly on the border between the gracile species
for their lighter build, particularly in the skull an
(heavier-skulled, with larger teeth) species follow
classify as Paranthropus.

NAME: Paranthropus or Australopithecus robustus (
TIME FRAME: About 2 to 1.5 million years ago.
VITAL STATS: Similar body to A. africanus (see pre
nitely getting bigger (530 cubic centimeters). Co
size between females and males, with males standi
tall and weighing about ninety-two pounds, and
seven inches and coming in at a svelte seventy-one
COMMENTS: Nobody's sure of the exact relationshi
This one was discovered in South Africa by Rober
"Nutcracker Man" (below), it is assigned to the ge
searchers, and to Australopithecus by others. Onc
strates a powerful chewing mechanism, made for e
which suggests these guys might have been the
make sense, since at this point we're on the verge
of food might have been getting scarce. There
species may have been using tools as well, since ani
sils might have been used for digging, and P. robus
enough to suggest some fine motor skills.

NAME: Paranthropus or Australopithecus boisei ("su
TIME FRAME: 2.1 to 1.1 million years ago.

SCIENCE 527

tralopithecus group (especially
ad end). Biggest debate stems
ed nearby bore cuts from stone
ool user and also that such be­
est stone tools, thought to be
nearby.)

llion years ago.
the advanced. Small brain size
ll are reminiscent o£A. afaren-
along with evidence of power­
grains and other tough foods.
" a fossil discovered in 1984 in
ally can't make up their minds
Paranthropus genus, since it is
s described previously (known
nd teeth) and the more robust
wing, which many researchers

(Take your pick.)

eviously), but the brain's defi­
nsiderable difference in body
ing about four feet four inches
d females standing three feet
e pounds.
ip between the robust species.
rt Broom in 1938. Along with
enus Paranthropus by some re­
ce again, this species demon­
eating tough and coarse foods,
first vegetarians. This would
of an ice age, so certain kinds
is some speculation that the
imal bones found with the fos­
stus' hand bones are developed

uper robust")

5*8 AN I N C O M P L E T E

VITAL STATS: Similar in many
five and a half feet and weighi
(he was known as the "Nutcrac
timeters from front to back. T
specializing in nuts, roots, and
COMMENTS: T h e first P. boisei
first for that area—by Mary L
you seeing a pattern here?)

NAME: Homo habilis ("handy m
TIME FRAME: Somewhere betw
VITAL STATS: Four and a half
about 750 cubic centimeters.
temporal lobes, and thus gre
speech.
COMMENTS: Handy man cle
smaller than his australopithe
about anything he could get
too small to take on big gam
leopards.

NAME: Homo géorgiens (named
found)
TIME FRAME: About 1.8 millio
VITAL STATS: A transitional sp
COMMENTS: Discovered in 20
mind-set. Before H. géorgien
(comparatively speaking) H. er
no earlier than 1 million yea
water.

NAME: Homo erectus ("erect m
TIME FRAME: From 1.8 millio
VITAL STATS: Nearly our size, w
750 and 1225 cubic centimete
modern humans. Despite its
graceful walker than modern h
big-brained infants.
COMMENTS: A very Atkins-li
smaller gut than the species th
duced the first hand axes, and
rude beginnings of culture. Th

E EDUCATION

ways to P robustus, but beefier, standing as tall as
ing as much as 150 pounds. Had even bigger teeth
cker Man"), with some molars measuring two cen­
This suggests that these guys were still vegetarians,
d tasty tubers.
i specimen was discovered in 1959 in Tanzania—a
Leakey. (Yes, that would be Richard's mom—are

man")
ween 2.4 and 1.5 million years ago.
f to five feet tall, 64 to 100 pounds, brain volume

Higher forehead indicates developed frontal and
eater reasoning powers. Possibly capable of basic

early used tools—thus his name. Was generally
ecine cousins and had smaller teeth, so he ate just
hold of, including meat. However, H. habilis was

e, so his bigger brain came in handy to outsmart

d after Georgia, the ex-Soviet country where it was

on years ago.
pecies between H. habilis and H. erectus.
002, this specimen challenges the "out of Africa"
ns, hominids—specifically, the highly intelligent
rectus—were thought to have ventured into Europe
ars ago. H. géorgiens blows that theory out of the

man")
on to 300,000 years ago.
with smaller jaw and larger brain (varying between
ers) than its predecessors. Probably stronger than

name, not the first to stand upright, but a more
humans, whose frames have had to compensate for

ike protein-rich diet meant a larger brain and a
hat came before it. T h e good news: H. erectus pro­
d was the first to make use of fire and shelter—the
he bad news: Some of the skull fossils discovered

revealed that the brains had been removed prior to d
tus might have been a cannibal.

NAME: Homo ergaster ("work man")
TIME FRAME: 1.7 to 1.5 million years ago.
VITAL STATS: Despite differences (different-shaped
African species is pretty much the same as the Eura
entists classify H ergaster as an earlier version of
chicken-and-egg situation.
COMMENTS: As the name suggests, this species ha
Notable for the 1984 find of Turkana Boy, an al
lanky eleven-year-old adolescent. Considered the
science, since a female H ergaster was found to b
nasty bone disease, meaning that other members o
after her.

NAME: Homo sapiens ("wise man")
TIME FRAME: From about 600,000 to 100,000 year
VITAL STATS: Flatter faces, bigger brains (about 83
still had bulging browridges.
COMMENTS: Also known as Homo heidelbergensis,
where the first fossils were found back in 1907. N
H. erectus segued slowly into H sapiens. H e hun
wooden tools, and may have launched language. (T
for several hundred millennia, however.)

NAME: Homo sapiens neanderthalensis (after the N
Germany, where they were first discovered)
TIME FRAME: From about 250,000 to 30,000 years
VITAL STATS: Not hunched brutes, as popularly beli
in 1856, just happened to be that of a big, arthritic
powerfully built, short (average male height was
solid; probably an adaptation to the nasty Ice Age
COMMENTS: Generally accepted as a subspecies o
by some to be a separate species, Homo neandertha
mans to conduct funerals, as evidenced by remains
derthal gravesite. The Neanderthals disappeared
years ago, to be replaced by Cro-Magnons, a hippe
sponsible for the celebrated cave paintings in Las
whether the Neanderthals died out, were killed, o
selves into oblivion. Or maybe we all have a trace
don't know it.

SCIENCE 529
death, suggesting that H. erec­

d brows, smaller brains), this
asian erectus. In fact, some sci­
f H erectus, but it's a bit of a

ad a pretty extensive toolbox.
lmost complete skeleton of a
e first hominid with a con­
e in the advanced stages of a
of the tribe must have looked

rs ago.
3 percent the size of ours), but

, from Heidelberg, Germany,
No miracle makeovers here—
nted, cooked his food, made
The word saute'did not appear

eander Thai—or "valley"—of

ago.
ieved; the first skeleton, found
specimen. They were actually
five feet six inches) and very
climate.
o f H. sapiens, though believed
alensis. Probably the first hu­
s of flower pollen at a Nean­
d mysteriously about 35,000
er subspecies of H. sapiens re­
caux, France. Nobody is sure
or simply intermarried them­
of Neanderthal in us and just

53° AN I N C O M P L E T E

N A M E : Homo floresiensis (fro
discovered)
T I M E FRAME: 94,000 to 12,00
VITAL STATS: Nicknamed the
tures. The most complete ske
a little taller than three feet a
were only about as big as gr
clearly used fire.
COMMENTS: The Hobbits hav
paleontology has it that hom
So, what to make of these gu
sapiens and were clearly sma
wildlife (including their favor
Even weirder, local Indonesia
Gogo, who had a reputation a
from the serving plates to the

N A M E : Homo sapiens sapiens
TIME FRAME: From about 195
VITAL STATS: Look in the mirr
centimeters and you wouldn't
COMMENTS: Our subspecies,
until relatively recendy; they
agriculture 12,000 years ago
didn't invent the Slinky until t

THE

Genetic engineering is the pr
into the cells of another, there
designed for. (But they still w
engineering, or recombinant-
churning out precious human
ping the human gene respons
mannered bacterium found in
pig died, then harvesting its p
successful with microorganism
made to mimic those of hum
stock: pigs that gain weight
working on the problem of ge

E EDUCATION

om Flores, the Indonesian island where they were

00 years ago.
Hobbits, and for good reason; these were wee crea­
eleton was from a thirty-year-old female who stood
and weighed a slight fifty-five pounds. Their brains
rapefruits. Still, they made a variety of tools and

ve put a lot of scientists into a quandary. Traditional
inid intellect is directly correlated with brain size.
uys, who existed at the same time as modern Homo
art enough to make weapons to hunt a variety of
rite prey, a rat the size of a small golden retriever)?
an myths mention hairy little creatures called Ebu
as the worst sort of dinner guests, eating everything
e village infants.

("wise, wise man")
5,000 years ago to today and perhaps even tomorrow.
ror. Your brain probably logs in at about 1,350 cubic

kick yourself out of bed.
right or wrong. Its members were hunter-gatherers
domesticated animals 18,000 years ago, invented
o, founded cities only about 5,000 years ago, and
the mid-twentieth century.

SPLICE OF LIFE

rocess that inserts genes from one living organism
eby custom-tailoring them to do work they weren't
won't do windows.) For example, thanks to genetic
-DNA technique, millions of bacteria are kept busy

insulin. Scientists built the microfactories by slip­
sible for the creation of insulin into E. co/i, a mild-
n our intestinal tract. (It beat waiting around until a
pancreas.) S o far, genetic engineering has been most
ms, plants, mice (whose immune systems have been
man beings), and—Stephen King, take note—live­

faster, cows that give more milk. Science is still
etting genetically altered D N A back into a human

cell and, we're told, isn't even close to a solution.
able to replace or repair bad genes, like the ones r
cystic fibrosis, sickle-cell anemia, and perhaps eve

To understand how genetic engineering works,
oxyribonucleic acid, or D N A , three letters even
First, go back to the days when you were a single
bryo, whose nucleus contained forty-six packages
three from each parent, carrying the coded info
characteristics, from hair color to susceptibility to
sexual orientation and propensity for violence. A
cell was issued forty-six identical chromosomes
cells, which, in anticipation of future mating, ha
The strandlike chromosomes are made up of sev
sponsible for a particular trait. And the genes are c
ical that runs the show, programming and operati
things have D N A in every cell. (The exception:
chemical cousin of D N A called RNA.) Indeed, i
structions coded in one person's D N A were written
sand encyclopedia-sized volumes. You might want

In 1953 Francis Crick and James Watson earned
that D N A is shaped like a spiral staircase, the fam
and sugars form the railing of the staircase, and p
various combinations form the steps—up to ab
human D N A . The order of the base pairs determi
tics of any shrub, egret, or stand-up comic.

Twenty years after this discovery, two Californ
and Herbert Boyer, found a way to perform D N A t
they who turned bacteria into human-insulin fac
human cell and cutting it with special enzymes at t
is found. Then, using more enzymes, the human
mid, a strand of extra D N A , found in bacteria. Wh
it creates millions of copies of itself, each with the n
produce not only insulin but growth hormone and

There's plenty of controversy and intrigue in th
organisms. In 1985, such an organism was tested
lab—semiofficially. A vaccine made by genetically
jected into 250 piglets. The test may have launc
ture—or a regulatory nightmare. What if the ge
mutates, affects humans? And, not to slip into ant
family farmers be able to afford the new technolo
islators who have a hard time formulating a polic
thing like this.

SCIENCE 531

Someday, however, we may be
responsible for such diseases as
en cancer.
, you've got to know about de­
n more important than MTV.
e cell—a fertilized egg, or em­
s called chromosomes, twenty-
rmation for all your inherited
o stress to, some would argue,
s your cells divided, each new

(except for your reproductive
ave only twenty-three apiece).
veral thousand genes, each re­
composed of D N A , the chem­
ing all life processes. All living
: Some viruses contain only a
it has been said that if the in­
n out, they would fill one thou­
t to wait for the movie.
d a Nobel Prize for discovering
mous double helix. Phosphates
pairs of four nitrogen bases in
bout three billion of them in
ines the particular characteris­

nia researchers, Stanley Cohen
transplants. For example, it was
tories, removing D N A from a
the spot where the needed gene
gene was snapped into a plas-
hen that bacterium reproduces,
new gene. In this way scientists

cancer-fighting interferon.
he world of genetically altered
d for the first time outside the
y altering a herpes virus was in­
ched a golden age of agricul­
ene-altered vaccine goes wild,
iclimax or anything, will small
ogy? You see the problem: leg
cy on Haiti set loose on some­