1. EVIDENCE FOR EVOLUTION

2. Charles Darwin
Charles Darwin was one of the first scientists to show proof of evolution through his findings in Origin of Species

3. Remember the theory of evolution includes:
Descent with Modification-Each living organism has descended, with changes from other species over time
Common Descent- were derived from common ancestors

4. Evidence of Evolution The Fossil Record
Geographic Distribution of Living Things
Similarities in Body Structures
Similarities in Early Development and DNA Structures

5. Evidence for Evolution
The Fossil Record-The layers show change
The fossil record contains examples of the transition from one species into another, as well as the origin of new physical features.

6. Evidence of Evolution
Geographic Distribution of Living Things-similar environments have similar types of organisms

7. Similarities in Body Structures
Similarities in Body Structure: how the bones are arranged. Similarities provide evidence that these animals all evolved from a common ancestor.
Similar structures that related species have inherited from a common ancestor are known as homologous structures.

9. Homologous Structures
The bones in a bird’s wing, a dolphin’s flipper, and a dog’s leg have similar structures. Which bones in the dog's leg match those in the flipper and which match those in the wing?

10. Evidence for Evolution
Vestigial organs-organs that serve no useful function in an organism
i.e.) appendix, miniature legs, arms

13. Similarities in Early Development

14. Similarities in Development
These four organisms all look similar during their early development. What are similarities and differences among them?
By looking at the early stages
of development, scientists can
infer evolutionary relationships
and the possibility of common
ancestors.

15. Ancestors and Relatives
Scientists infer that the species inherited many of the same genes from a common ancestor. Scientists compare the sequence of nitrogen bases in the DNA of different species to infer how closely related the two species are.
The more similar the DNA sequences, the more closely related the species are.

16. Ancestor: the actual or hypothetical form or stock from which an organism has developed or descended.
Relative: a person who is connected with another or others by blood or marriage.

17. Similarities in DNA and Protein Structure: The more similar the DNA sequences, the more closely related the species are.
Section of Cytochrome c Protein in Animals
The table shows the sequence of amino acids in one region of a protein, cytochrome c, for five different animals. Each letter corresponds to a different amino acid in the protein.

18. Summary of Darwin’s Theory
Individuals in nature differ from one another
Organisms in nature produce more offspring than can survive, and many of those who do not survive do not reproduce.

19. Summary of Darwin’s Theory
Because more organisms are produce than can survive, each species must struggle for resources
Each organism is unique, each has advantages and disadvantages in the struggle for existence

20. Summary (cont.)
Individuals best suited for the environment survive and reproduce most successful
Species change over time

21. Summary (cont.)
Species alive today descended with modification from species that lived in the past
All organisms on earth are united into a single family tree of life by common descent