2. Earth’s Early Atmosphere
had very little free oxygen
Contain: methane, CO2, H2O, Nitrogen, Ammonia, and Carbon Monoxide
Changes are constantly occurring … we notice them during volcanoes and earthquakes.

3. AGE OF THE EARTH 4.6 Billion yrs.
PALENTOLOGIST: Study fossils to understand the Earth’s origin
FOSSILS: Preserved remnant or remains of an organism that lived many years ago

4. Evidence of Evolution (Comparative Morphology)
Science comparing the structures of living things
2 Categories
Analogous Structures
Homologous Structure

5. Evidence of Evolution (Analogous Structures)
Serve the same purpose in different species but evolved independently
Did not evolve from the same structures in a common ancestor
pterodactlyl
bird
moth
bat

6. Evidence of Evolution (Homologous Structures)
Have a common origin but not necessarily a common function
(these bone pattern are similar/but have different functions)

7. Homologous vs Analogous

8. Evidence of Evolution (Embryology)
Study of the
earliest
stages of life,
before birth.

9. Evidence of Evolution (Biochemical)
Comparing genetic information
(the sequence of amino acids)
DNA Fingerprinting (gel electrophoresis)
Ex. Hemoglobin (red blood cell protein)
The amino acid sequence for this protein in humans is almost identical to the sequence in gorillas. Differ by one amino acid. In frogs, it differs by 67 amino acids. So, humans and gorillas shared a common ancestor more recently than humans and frogs.

10. Various Types of Fossils
TRACE
CAST (FILLED)
MOLD (EMPTY)
IMPRINTS
AMBER OR ICE

11. OPARIN’S THEORY
Suggested energy from the sun, lightning triggered chemical reactions to produce small organic molecules from the substances present in the atmosphere. The rain washed these into the ocean.
Called “ORGANIC SOUP” or Primordial Soup”

12. MILLER AND UREY Experiment p. 382
Tested Oparin’s hypothesis by simulating the conditions of early Earth in a laboratory
The experiment made a Protocell
Protocell: An ordered structure, enclosed in a membrane, that carries out some life.

13. SEDIMENTARY ROCK Fossils are usually found Layers form over time
The older the rocks the more primitive the organisms that left impressions.

14. HOW SCIENTIST DETERMINE AGE OF FOSSILS
(1) Relative Dating (p. 372)
(2) Radioactive Isotope
RELATIVE DATING
Undisturbed rock layers…
the layers at the surface
must be younger than
the deeper layers.
Younger rock on top.

15. RADIOACTIVE ISOTOPES Atoms in these isotopes are unstable
They breakdown (decay) overtime giving off radiation, form a new element.

16. HALF-LIFE
The amount of time it takes for one half of a radioactive isotope sample to break down.

17. UNDERSTANDING FOSSILS
By studying fossil records, scientist have been able to put together an outline of earth’s history called the GEOLOGIC TIME SCALE
Era: Largest division of time
Period: Subdivision of an Era
Extinct: Gone

18. GEOLOGIC TIME SCALE PRECAMBRIAN ERA
THE OLDEST
LIFE BEGAN---IN THE OCEANS
SINGLE CELL AND SIMPLE MULTICELLULAR ORGANISMS

19. PALEOZOIC ERA
MANY INVERTEBRATES
PLANTS AND ANIMALS MOVE TO LAND

20. MESOZOIC ERA REPTILES AGE
DINOSAURS DOMINATED THE WORLD FOR ABOUT 250 MILLION YEARS

21. CENOZOIC ERA
ERA OF THE MAMMALS AND THE BIRDS WE
LIVE
IN THIS
ERA!

22. THE ORGIN OF LIFE
Spontaneous Generation (Abiogenesis): The idea that nonliving material can produce living
Biogenesis: The idea that living organisms come only from other living organisms.

23. FAMOUS SCIENTIST Redi- Experiment using the jars and meat. (p. 380)
Pasteur- Experiment using the S-Shaped Flask that remained germ free (p. 381)

24. ENDOSYMBIONT THEORY P. 385 Proposes that eukaryotes evolved through
a symbiotic relationship
between ancient prokaryotes.