Thursday, April 28, 2005

469: Evolutionary biology Animal roots and shoots : Nature

Evolutionary biology Animal roots and shoots : Nature:

DNA sequence data from neglected animal groups support a controversial hypothesis of deep evolutionary history. Inferring that history using only whole-genome sequences can evidently be misleading.

Despite the comforting certainty of textbooks and 150 years of argument, the true relationships of the major groups (phyla) of animals remain contentious. In the late 1990s, a series of controversial papers used molecular evidence to propose a radical rearrangement of animal phyla1, 2, 3. Subsequently, analyses of whole-genome sequences from a few species showed strong, apparently conclusive, support for an older view4, 5, 6. Philippe et al., writing in Molecular Biology and Evolution7, now provide evidence from expanded data sets that supports the newer evolutionary tree, and also show why whole-genome data sets can lead phylogeneticists seriously astray.

Evolutionary hypotheses tested. More and better data form better hypotheses, which are in turn tested.