1. Do Now
What does it mean to evolve? Provide an example based on the modern theory of evolution.

2. Convergent Evolution Selective pressure
Selective Pressure: any phenomena which alters the behavior and fitness of living organisms within a given environment.
Converge- come together

3. Convergent Evolution
The process that occurs when organisms that are not closely related, independently evolve similar traits as a result of having to adapt to similar environments or ecological niches.

4. Similar traits independently evolve in unrelated species
Analogous structures: same function, different structures
Similar traits independently evolve in unrelated species

6. Bat wings and bird wings are analogous as flight structures: their structure and function have evolved by different routes from a flightless reptilian ancestor. Note for example that a good portion of the flight surface in bats consists of a membrane stretched between the extended digits (chiropatagium), whereas the digits of the bird are relatively small and do not support the flight surface.

7. Convergent Evolution leads to…
Analogous structures: Body parts that are similar in structure and functions that have no anatomical or embryological similarities
Ex. Bird wings and insect wings

8. Divergent Evolution
When related species become more and more different in response to different environments
Diverge: going apart
Allopatric speciation

10. Divergent Evolution leads to…
Homologous Structures:
Body parts that are alike because of a common ancestor
These structures may serve the same or different functions
Ex. Forelimbs

11. Homologous structures
Anatomically similar but different functions
Same origin

12. Coevolution

13. Coevolution
The change in the evolution of one species in response to a change in another species. Ex: Honeybees become dependent on flowers, and flowers become dependent on honeybees for survival.

15. Vestigial structures
Organs that were useful for an ancestors, but no longer useful in the modern day species.
Ex. Appendix
Jean Baptiste Lamarck discovered and named vestigial structures