Phylogeny - Research Article from Macmillan Science Library: Plant Sciences

This encyclopedia article consists of approximately 7 pages of information about Phylogeny.
This section contains 1,902 words
(approx. 7 pages at 300 words per page)
Buy the Phylogeny Encyclopedia Article

Theoretical Foundations

In his explicit phylogenetic scheme for land plants, Haeckel rejected theories of multiple origins for organisms, which he called polyphyletic. He used the term monophyly to describe a natural group of two or more taxa whose members are all descended from the nearest common ancestor. Phylogenies are based on monophyletic groups. The taxonomic theory of phylogenetic systematics is organized around the principles that organisms are related through descent from a common ancestor, that there are natural groups of monophyletic taxa, and that unique changes or modifications shared by members of a taxon are evidence of their evolutionary history.

Although monophyletic taxa exist in nature whether they are discovered or not, the goal of phylogenetic systematics is to reveal natural groups of taxa. The main principle of phylogenetic systematics is that natural groups are defined by uniquely shared evolutionary novelties, or homologous characters. A character is a heritable...

(read more)

This section contains 1,902 words
(approx. 7 pages at 300 words per page)
Buy the Phylogeny Encyclopedia Article
Copyrights
Macmillan Science Library: Plant Sciences
Phylogeny from Macmillan Science Library: Plant Sciences. Copyright © 2001-2006 by Macmillan Reference USA, an imprint of the Gale Group. All rights reserved.
Follow Us on Facebook