BIOLOGY 1M03 Chapter Notes - Chapter 27: Paleozoic, Proterozoic, Ctenophora
8 Feb 2016
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Chapter 27: phylogenies and the history of life. Phylogenetic trees are diagrams that may be interpreted as documenting inferred evolutionary relationships among organisms and are constructed from data. The fossil record provides physical evidence about organisms that lived in the past. Adaptive radiations are a major pattern in evolutionary history, rapid diversifications associated with new ecological opportunities and new morphological innovations. Mass extinctions have occurred repeatedly throughout evolutionary history, environmental catastrophes that rapidly eliminate most species. Biologists consider profound changes in life" on earth over immense time periods. Two major analytical tools that biologists use to reconstruct evolutionary history are phylogenetic trees and the fossil record. The evolutionary history of a group of organisms is called a phylogeny. A phylogenetic tree is a diagram that may be interpreted as showing inferred ancestor- descendant relationships among populations or species. An inferred ancestor and all its inferred descendants form a monophyletic group (also called a lineage)
