Biology 1001A Study Guide - Quiz Guide: Land Bridge, Collision Theory, Reproductive Isolation
Document Summary
Similarity does not always imply relatedness: not all similarities are homologies and not all homologies are synapomorphies, according to cladistics, shared derived traits are the only important similarities in phylogenies pay attention to synapomorphies. Monophyletic groupings: monophyletic: related by a single common ancestor, monophyletic groupings include all descents of the mrca of the group, only monophyletic groupings are used in cladistics, many traditionally recognized groups are not monophyletic prokaryotes, fish, etc. Galapagos islands, after the extinction events: results in diversification, ex. Angiosperms use animals as pollinators different animals, reproductive isolation occurs: adapt to attract specific pollinators high rates of speciation. Severity of k-t extinction: after the k-t extinction event, more than half of all species of reptiles became extinct, and many groups did not recover their genetic diversity, was not the largest extinction event. Evidence of collision theory: the collision theory: late cretaceous extinctions occurred as a result of the collision of an asteroid with earth.
