BIO SCI 1A Lecture Notes - Lecture 15: Hominidae, Orangutan, Thumb
5 Mar 2016
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Document Summary
Rates vary from group to group, and within groups. Lungfish evolve even more slowly: show little change in the last 150 million years. Rates also vary from one period to another throughout history. Species richness: the larger the number of species in a lineage, the greater the opportunities for new species to form. Species range: the larger the geographical range, the greater the likelihood that a physical barrier will divide it. Mobility differences: species with poor dispersal abilities are unlikely to move across borders and establish new populations. Complex discriminations: organisms that make complex mate choice discriminations are more likely to speciate. Use of multiple criteria: size, shape, general appearance, behavior. This is significant because mate selection is a major cause of evolutionary change. Short generation time: because there are more generations per unit of time, there is a greater potential for evolutionary change per unit of time. (example: bacteria) So slow that the fossil record may not show change.
