|
|
Article: Phylogenetic Relationships of Major Groups
- Article from:
- Animal Sciences
- Author:
CopyrightCOPYRIGHT 2002 The Gale Group Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
|
Phylogenetic Relationships of Major Groups
The evolutionary history of a species or group of related species is called its
phylogeny
. When the evolutionary history is diagrammed, it is shown in the shape of a tree that traces evolutionary relationships as they have changed over time. The reconstruction of phylogenetic history is part of the field of
systematics
. The diversity of the phylogenetic tree is a reflection of speciation.
A phylogenetic tree shows not only how closely related two groups are but also how once-related species evolved independently. The further back in time a group branched represents a greater amount of time for divergent evolution to occur. When systematists ...