Filogenia profunda: como uma árvore pode ajudar a caracterizar a vida primeva na Terra

quarta-feira, maio 25, 2011

Deep Phylogeny—How a Tree Can Help Characterize Early Life on Earth

Eric A. Gaucher, James T. Kratzer and Ryan N. Randall

Author Affiliations

School of Biology, School of Chemistry, and Parker H. Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia

Source: PNAS


The Darwinian concept of biological evolution assumes that life on Earth shares a common ancestor. The diversification of this common ancestor through speciation events and vertical transmission of genetic material implies that the classification of life can be illustrated in a tree-like manner, commonly referred to as the Tree of Life. This article describes features of the Tree of Life, such as how the tree has been both pruned and become bushier throughout the past century as our knowledge of biology has expanded. We present current views that the classification of life may be best illustrated as a ring or even a coral with tree-like characteristics. This article also discusses how the organization of the Tree of Life offers clues about ancient life on Earth. In particular, we focus on the environmental conditions and temperature history of Precambrian life and show how chemical, biological, and geological data can converge to better understand this history.

“You know, a tree is a tree. How many more do you need to look at?”–Ronald Reagan (Governor of California), quoted in the Sacramento Bee, opposing expansion of Redwood National Park, March 3, 1966

Copyright © 2010 Cold Spring Harbor Laboratory Press; all rights reserved