A phylogeny (or phylogenesis) is the origin and evolution of a set of organisms, usually of a species. A major task of systematics is to determine the ancestral relationships among known species (both living and extinct), and the most commonly used methods to infer phylogenies include cladistics, phenetics, maximum likelihood, and Bayesian.
During the late 19th century, the theory of recapitulation, or Haeckel's biogenetic law, was widely accepted. This theory was often expressed as "ontogeny recapitulates phylogeny", i.e. that the development of an organism exactly mirrors the evolutionary development of the species. The early version of this hypothesis has since been rejected as being oversimplified and misleading. However, modern biology recognizes numerous connections between ontogeny and phylogeny, explains them using evolutionary theory, and views them as supporting evidence for that theory. See the article on ontogeny and phylogeny.
In biology, phylogenetics (Greek: phylon = tribe, race and genetikos = relative to birth, from genesis = birth) is the study of evolutionary relatedness among various groups of organisms (e.g., species, populations).
Phylogenetictaxonomy, which is an offshoot of, but not a logical consequence of, phylogeneticsystematics, constitutes a means of classifying groups of organisms according to degree of evolutionary relatedness.
Share your thoughts, questions and commentary here
Want to know more? Search encyclopedia, statistics and forums:
Press Releases |
The Wikipedia article included on this page is licensed under the
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m