Notes for March 22. 2006

Obj SW

1. Differentiate between direct and indirect evidence for evolution.
2. Compare organisms for evidence of evolution
3. Discover how variation in an organism cal lead to its survival.

Evidence of Evolution

Darwin Review
--5 year journey on the HMS Beagle
--Traveled primarily in tropical regions
--Darwin looked at a lot of fossils.

Indirect evidence
1. fossils: evidence of life long ago

2. comparative anatomy
**homologous swtructure: similar structures used for different purposes (whale forelimb, crocodile forelimb and bird wing. These are similar structures that serve different purposes)
**analogous: different structures used for the same purpose (Butterfly wings (scales) and bird wings (bones, muscle, feathers).
**vestigial structures: structures that serve no purpose (tonsils, appendix, wisdom teeth).

3. Comparative embryology
**Comparing the earliest stages of growth and development in an organism.

4 . Comparative Biochemistry
**nucleic acids, amino acids

**comparing DNA (proteins and amino acids)

Direct evidence
–adaptation: any change in an organism that aids in its chance for survival.
1. Structural Adaptation
**Mimicry: copying the appearance of a more dangerous organism that aids in survival. (yellow and black fly)
**camouflage: blending into surroundings
**Physiological adaptation: Change in an organism’s metabolic processes.