BIOL108 Lecture Notes - Lecture 4: Hybrid Zone, Cichlid, Phenotypic Plasticity

• School: University of Alberta
• Department: Biology (Biological Sciences)
• Course: BIOL108
• Professor: Trevor Pasanen

Document Summary

Remember that all modes of natural selection lead to evolution of adaptations (and that natural selection is the only thing that leads to adaptations!) Each stage must have had fitness advantages. A range of eye complexity in the phylum mollusca. Therefore octopus eyes are better because they do not have blind spots while. The vertebrate eye has a serious design flaw we do. Camouflaged, but it swims on its sides, so the camouflage doesn"t help. Can only modify traits from existing variation. It has no goal and does not strive to create perfectly designed traits . But evolution by natural selection is not all due to chance . Genetic drift change in allelic frequencies due to random or chance events. whereas, the evolution through natural selection is the change in allelic frequencies due to heritable fitness differentials. Population gets reduced to small size . As diversity goes down, you are more susceptible to environmental challenges.