BLG 144 Chapter 27: Chapter 27
27 Dec 2017
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Document Summary
Chapter 27 phylogenies and the history of life: Phylogenetic trees document the evolutionary relationship among organisms and are estimated from data. The fossil record provides physical evidence of organisms that lived in the past. Adaptive radiation is a major pattern in the history of life. They are instances of rapid diversification associated with new ecological opportunities and new morphological innovations. Mass extinctions have occurred repeatedly throughout the history of life. They are environmental catastrophes that rapidly eliminate most of the species alive. Phylogeny the evolutionary history of a group of organisms. Node represents the point in time when an ancestral species split into 2+ descendant species. Tip the endpoint of a branch, represents a group that is living today or ended in extinction. Ancestral trait is a characteristic that existed in an ancestor. Derived trait one that is modified from that of the ancestral trait, found in a descendant.
