Evolution - somersetacademy.enschool.org

EVOLUTION

ORIGIN OF LIFE

UPCOMING DATES AND ASSIGNMENTS

• 3/30 (TODAY!)

• Food Web Powerpoint due by midnight
• Email to [email protected]
• Instructions online

• ECOLOGY TEST

• Assigned online (PearsonSuccess.net)
• DUE 4/10/16 by midnight

• March 30 – April 15: EVOLUTION

• Quiz and test dates to be announced

ECOLOGY TEST

• Assigned online (PearsonSuccess.net)
• DUE 4/10/16 by midnight
• Login Information: in your ISN

• User name

• BA_FirstinitialLastname (BA_Cmonster)

• Password

• Not being able to login is not an excuse
• May use computers in this room before or after school to complete test
• 36 questions; may use notes

EVOLUTION – TENTATIVE SCHEDULE

• 3/30 (Wed): Origins of Life, Endosymbiosis
• 4/1 (Fri): Evidence for Evolution
• 4/5 (Tues): Natural Selection
• 4/7 (Thurs): QUIZ; Classification of organisms
• 4/11 (Mon): Domains and Kingdoms
• 4/13 (Wed): Hominid evolution
• 4/15 (Fri): Evolution TEST

BIGTHE BANG

EVOLUTION: THE BIG BANG

• 10-20 billion years ago
all matter, energy,
space and time came
into existence

• The universe expanded
very rapidly and began
to cool down

• Matter began to
condense and new
atoms/particles
formed



EVOLUTION: THE ACCRETION THEORY

• 4.6 billion years ago dust and light
elements began to collide and condense
together in a process called accretion

• The larger the clump the more surface
area it has, the faster it gathers more
particles

• When large enough they develop their
own gravitational field and eventually
become the planets we know today

• CONGRATULATIONS!

EVOLUTION: EARTH ATMOSPHERE

• 4.6 BYA - Surface was mostly molten and
atmosphere was formed mainly from
hydrogen sulfide, methane and 200 times as
much carbon dioxide

• 4 to 2.5 BYA – Cyanobacteria flourished in
oceans and started producing oxygen

EVOLUTION: EARTH ATMOSPHERE

• 700 to 550 MYA – Oxygen levels reached about 4%
of atmosphere causing an explosion of oxygen using
lifeforms (Cambrian explosion)

• 430 MYA – Small plants and invertebrates appear
on land

• 416 to 397 MYA – Plants and animals evolve and
first four footed animals begin to form

ORIGIN OF LIFE

• Evolution – Change in the
genetic makeup of a population
of organisms over time

• Abiogenesis - the process of life
arising from non-living matter

• Miller-Urey experiment
produced organic compounds
from simulated early Earth
atmosphere

• https://www.youtube.com/wat
ch?v=iahBQolXQH8

ORIGIN OF LIFE TIMELINE

PROKARYOTES AND EUKARYOTE

• The first cells on Earth were heterotrophic
prokaryotes (bacteria)

• Heterotroph – organism that can not make its own
food and eats in order to survive

• Early prokaryotes consumed organic matter from
pre-historic sea

• Some mutated into autotrophs (produce own food)

PROKARYOTES AND EUKARYOTES

• Early autotrophs manufactured own food in two ways:
• 1. Photosynthesis – producing food from light energy

a. Stromatolites – single celled cyanobacteria; clumped
into rock like structures

• 2. Chemosynthesis – energy from inorganic materials
(deep sea hydrothermal vents)

PROKARYOTES AND EUKARYOTES

• Prokaryotes, such as mitochondria and chloroplast,
began to live inside larger prokaryotes

• Resulted in the formation of more complex cells
that we now call eukaryotic cells

• Theory of Endosymbiosis – origin of eukaryotic cells
from mutualistic relationship between prokaryotes

PROKARYOTES AND EUKARYOTES

• Evidence supporting Theory of Endosymbiosis:
• 1. Mitochondria and chloroplast have their own
DNA
• 2. DNA resembles the DNA of prokaryotes more
than DNA of eukaryotes
• 3. Mitochondria and chloroplast have their own
double membrane

PROKARYOTES AND EUKARYOTES