Biology 1201A Chapter Notes - Chapter 20: Dont, Reptile, Monophyly
26 Feb 2016
School
Department
Course
Professor
Document Summary
Prokaryotes and dicots are not monophyletic groups, they are not a group of organisms just a grouping system. If two taxa are related to one another they should have things in common, because the traits are inherited from a common ancestor. Homoplasies- bad, misleading, will trip us up when building trees. Seem similar, but it is not inherited due to common ancestry. These may be a result of convergent evolution: independent evolutionary events resulting in similar solutions to similar environments. No gene flow, no common ancestry, but there are similar selection pressures and environments so their traits converge. ex. hippos and alligators both have eyes higher up on their head and towards the sides. Different ancestral past that led to the same look. Divergent evolution - start very close with a common evolutionary ancestor, but has experienced divergence may look very different. Misleadingly makes taxa appear unrelated despite a recent common ancestor.
