1. Theory of Evolution
Ms. Cuthrell

2. 3.4.1
Explain how fossil, biochemical, and anatomical evidence support the theory of evolution.

3. Life 1st appeared in the oceans between 3.9 and 3.4 billion years ago.
Urey and Miller’s “Primordial Soup” model proposed that life formed from organic molecules produced by solar radiation, volcanoes, and lightning.

4. Origin of Life
In the past, many believed in spontaneous generation, the idea that nonliving material can produce life.

5. Spontaneous Generation Disproved
In 1668, Italian physician, Francesco Redi, disproved that maggots and most large organisms did not arise spontaneously.

6. Louis Pasteur
In the mid-1800s, Pasteur disproved spontaneous generation of microorganisms, which led to belief in biogenesis.

7. Idea of Biogenesis
Biogenesis: living organisms only come from living organisms.

8. Evolution of Cells 1st cells (most primitive life forms)
Anaerobic- no oxygen required
Prokaryotic- no nucleus

9. 2 Groups of Prokaryotes
Archaebacteria- do not have a chemical called peptidoglycan in their cell walls.
Live in extreme environments. Some still live today.
Eubacteria- have a chemical called peptidoglycan in their cell walls.
Present day example- E. Coli
Earliest fossil bacteria dates back to over 2,500 million years ago (2.5 billion).

10. Cyanobacteria Photosynthesizing archaebacteria.
Oxygen appeared in the atmosphere.
Led to ozone layer, which enabled evolution of eukaryotes.

11. The Endosymbiont Theory
Idea that eukaryotes evolved through a symbiotic relationship between ancient prokaryotes is called endosymbiosis.
Evidence- mitochondria and chloroplast have their own DNA.

12. Eukaryotes
The first were protists, unicellular and then multicellular.
From protists evolved fungi, plants, and animals.
Plants and fungi formed mycorrhizae, and were the first multicellular organisms to live on land.
Mycorrhizae- mutualism between plants and fungi; fungus provides minerals to plant, plant provides nutrients to fungus.

13. Eukaryotes The first vertebrates to invade dry land were amphibians.
The extinction of many reptile species enabled birds and mammals to become the dominant vertebrates on land.

14. Evidence for Evolution
Fossils
Relative Dating- comparing the order of fossils in a rock layers
Absolute Dating- measuring chemical qualities of a fossil or rock layer that a fossil is found in.

15. Other Evidence for Evolution
Shared anatomical structures
Homologous structures- similar structures with a common evolutionary origin.
Vestigial structures- body structure in a present-day organism that no longer serves its original purpose.

16. Other Evidence for Evolution
Biochemical similarities- genetic makeup (DNA is always the best evidence to support relationships between organisms.)