1. Evolution

2. What is evolution? Change over time

3. Questions? *Have living things on Earth changed over time? *How have living things on earth changed? *What causes living things to change? *How often do the changes happen?

4. The 1 st organisms were probably … prokaryotes single celled Anaerobic Heterotrophic Using RNA as genetic information Similar to the Archaebacteria of today.

5. Evolution of Chemosynthesis …the use of inorganic substances (CO 2 ) as a source to produce organic compounds for energy. These types of organisms probably evolved later than the 1 st heterotrophs.

6. Evolution of Photosynthetic & cell respiration 1 st photosynthetic organisms were probably similar to cyanobacteria. Oxygen is a product of respiration. Oxygen is deadly to anaerobic organisms, some organisms developed mechanisms to use oxygen to breakdown organic compounds (cell respiration!)

7. Cyanobacteria

8. Evolution of Eukaryotes Theory of Endosymbiosis (Endosymbiant Theory) – an organism “invaded” or was ingested/eaten by another and both continued to function, but as a single organism. **Explains the development of mitochondria & chloroplasts!

9. Each new evolutionary step took millions – billions of years. 1 st organism – over 3.5 billion years ago 1 st chemosynthetic org. – about 3.5 billion years ago 1 st photosynthetic organism – about 3 billion years ago (aerobic organisms developed shortly thereafter) 1 st Eukaryote about 2 billion years ago 1 st Multicelled organism – about 1.2 -1.5 billion years ago

10. Each new adaptation was advantageous for the organisms, they thrived and produced more of those organisms.

11. Evidence for Evolution

12. There are 5 pieces of evidence that supports evolution. 1)Fossils 2)Biochemistry 3)Biogeography 4)Embryonic development 5)Anatomy (Morphology)

13. 1) Fossils -Remnants of living things from the past -Fossil record shows stratification: things that lived long ago are buried deeper than the more recent organisms. (Law of Superposition)

15. 2) Biochemistry - By looking at DNA sequence we can see which organisms are more closely related.

17. 3) Biogeography -We can compare organisms that live in similar environments in different locations -i.e.: we can compare desert organisms in the US the desert organisms in Africa

19. 4) Embryonic development - In early stages of development there are many similarities between different vertebrates. Some organisms are very similar throughout there embryonic development and are more closely related.

21. 5) Anatomy (morphology) A)Homologous structures – structures that come from a common ancestor B)Analogous structures – structures that have similar function but do not come from a common ancestor C)Vestigial structures – structure that does not seem to have a function, but may have at one time functioned.

22. Homologous structures

23. Analogous structures

24. Vestigial structures