Bumper sticker of the day: "He who laughs last thinks slowest."

Review of Lecture 23: The wheel of fortune: Evolution of higher taxa.

1. Diversity of life on earth is the direct result of the process of evolution.

2. Natural selection: principle mechanism of evolution; acts on populations (microevolution).

3. Adaptations: enable survival in changing environment; key innovation = major change in some character that enables adaptation to new niche.

4. Adaptive radiation: speciation resulting from changes in morphology and adaptation to new niche.

5. Evolutionary lineage: ancestor-descent sequence extending through time. Related groups have shared, derived characters. May include extinct relatives.

6. Convergent evolution: unrelated populations with similar special adaptations. They look alike even though they aren't related.

7. Evolution above the species level (macroevolution) involves the same processes observed in population. The differences are that the intermediate groups, which form a continuum of characters at the population and species-level, are missing due to extinction and divergence over time.

Return to PB 102 Class Notes Homepage
Please send your suggestions, comments, corrections, and/or questions to wolfe.205@osu.edu
Last updated May 28, 1997.