EVOLUTION

ORIGIN OF LIFE

UPCOMING DATES AND ASSIGNMENTS

• 3/30 (TODAY!)

• Food Web Powerpoint due by midnight

• Email to Lbarraco@somersetacademy.com

• 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

THE BIG 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/watch?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