1. of Evolution

2. What Did Darwin Explain in his Book, On the Origin of Species?
He explained his theory of Evolution by Natural Selection
He presented evidence that living species evolved from organisms that lived in the past
The evidence comes from multiple fields of science

3. The Fossil Record
Fossils are traces of organisms that lived in the past
Can tell relative age of organisms (which came first)
One can compare fossils of extinct organisms to living organisms to reveal patterns of gradual change
Darwin noticed many “gaps”, but many new fossils have been found that fill some of these gaps.
Conditions that create fossils are rare so we will never find fossils of every species that ever lived

4. Practice looking at the Fossil Record

5. Biogeography The study of the locations of organisms around the world
Suggests that similar environments shape the evolution of organisms in similar ways

6. Embryology The study of the development of embryos
One can compare the embryonic stages of different organisms to look for similar patterns and structures
Similarities most likely derive from an ancestor that the species have in common

7. Which one is the rabbit?

8. Anatomy
Scientists can compare the bodily structure of different species to find clues about how they are related
Many internal similarities are best explained by evolution
Homologous structures are characteristics that are similar in two or more species and that have been inherited from a common ancestor
They don’t necessarily function similarly

9. What similarities do you see?

10. Color the common bone structures on the next page.

11. Anatomy Vestigial Structures
A structure or organ is vestigial if it has diminished in size or usefulness in the course of evolution
Vestigial structures are markers of evolutionary descent. For example, boa constrictors, which are descended from four-legged reptiles, grow tiny hind legs.

12. Top 10 Useless Limbs (and Other Vestigial Organs)
10 - The wings on flightless birds

13. Top 10 Useless Limbs (and Other Vestigial Organs)
9 - Hind leg bones on whales

14. Top 10 Useless Limbs (and Other Vestigial Organs)
8 - Erector Pili and Body Hair on Humans

15. Top 10 Useless Limbs (and Other Vestigial Organs)
7 - The Human Tailbone (Coccyx)

16. Top 10 Useless Limbs (and Other Vestigial Organs)
6 – Eyes of blind fish

17. Top 10 Useless Limbs (and Other Vestigial Organs)
5 – Wisdom teeth in humans

18. Top 10 Useless Limbs (and Other Vestigial Organs)
4 – The Sexual Organs of Dandelions

19. Top 10 Useless Limbs (and Other Vestigial Organs)
3 – Fake Sex in Virgin Whiptail Lizards (Vestigial Behavior)

20. Top 10 Useless Limbs (and Other Vestigial Organs)
2 – Male breast tissue and nipples

21. Top 10 Useless Limbs (and Other Vestigial Organs)
1 – The Human Appendix

22. Biochemistry
A comparison of DNA sequences shows that some species are more genetically similar than others
Similarities are evidence of hereditary relationships among species

23. Whale Evolution