1. Natural Selection State Standard Objectives:
Describe the process of natural selection
State the four types of evidence that natural selection has happened over time

2. Charles Darwin 1831 set sail on HMS Beagle
Through the voyage, as a naturalist, Darwin observed many different species and came up with a theory

4. Galapagos Islands – Darwin's finches
Collected different species of finches from different islands
Unique to the island but similar to species on the mainland
Had different beaks
Ate different types of
food- were specialized

7. Darwin's theory Tried to explain this change over time
Species competed for resources
Therefore they changed over time to reduce competition
If they didn’t change, too much competition and they died
The ones who changed and lived, produced offspring, passing on the change (genes and characteristics)

8. Natural Selection
Selection is made on which individuals in a species will survive to reproduce
Key factor is the environment
The environmental factors will pick who lives and who dies
Organisms with favorable variations survive, reproduce and pass on those variations (characteristics) to the next generation
A possible explanation for the theory of evolution???
– a change through time

10. Adaptation A species becomes better suited to it’s environment
A change in a genetic trait
could be a mutation that gives and advantage to the organism to survive over the rest

11. Giraffes

12. Evidence of Change over Time, through natural Selection
Fossil Record
Comparative anatomy – bone structure
embryo development
DNA and proteins

13. Fossil Record

14. Comparative Anatomy - Bones
Analogous structure –
NO common evolutionary origin
are similar only in function
Bird wing and butterfly wing
Homologous Structure –
Common evolutionary origin
Similar in arrangement, function or both
Crocodile and whale

16. Vestigial Structure –changed from original purpose, but useful in an ancestor

17. Embryo Development