1. Evidence for Evolution

2. Fossil Evidence Layers of sedimentary rock contain fossils
new layers cover older ones, creating a record over time
fossils within layers show that a succession of organisms have populated Earth throughout a long period of time

3. Fossil Evidence
A record showing us that today’s organisms descended from ancestral species
We call these transitional fossils
Tiktaalik roseae- Discovered in Said to be the link between fish and 4-legged animals

5. Anatomical Evidence Homologous Structures Similar function
Similar development
Different Function
Close evolutionary relationship- recent common ancestor

7. Anatomical Evidence Analogous Structures similar functions
similar external form
different internal structure & development
different origin
no evolutionary relationship

9. Anatomical Evolution Convergent Evolution Parallel Evolution
evolved similar “solution” to similar “problems”
Examples: Fish and dolphins
Not closely related
Parallel Evolution
filling similar ecological roles in similar environments, so similar adaptations were selected
Again, not closely related

12. Anatomical Evidence Vestigial Organs
Modern animals may have structures that serve little or no function
snakes & whales — remains of pelvis & leg bones of walking ancestors
eyes on blind cave fish
human tail bone and appendix

13. Anatomical Evidence Embryology
Similar embryological development in closely related species
All vertebrate embryos have similar structures at different stages of development

15. Molecular Evidence Comparing DNA & protein structure
There is a universal genetic code (DNA and RNA)
Comparing common genes
Cytochrome C (respiration)
Hemoglobin (gas exchange)
Closely related species have sequences that are more similar than distantly related species