BIO153H5 Chapter Notes - Chapter 27: Cenozoic, Paleozoic, Doushantuo Formation
Document Summary
Phylogenies and the fossil record are the major tools that biologists use to study the history of life. The cambrian explosion was the rapid morphological and ecological diversification of animals that occurred during the cambrian period. Adaptive radiations are 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 rapidly eliminate most of the species alive in a more or less random manner. Phylogeny the evolutionary history of a groups of organisms: are usually depicted in the form of a phylogenetic tree. Phylogenetic tree shows the ancestor-descendant relationships among populations or species, ad clarifies who is related to whom. Branch represents a population through time. Node the point where two branches diverge (also known as a fork: represents the point in time when an ancestral group split into two or more descendant groups.
