The Journal of Eukaryotic Microbiology has just published a very nice paper showing how the details of protist evolution "dispel the myths of intelligent design." Generally, protists are "unicellular eukaryotes that either exist as independent cells, or if they occur in colonies, do not show differentiation into tissues." Think amoebae or foraminifera.
Biologists Mark Farmer and Andrea Habura address various ID claims and show how the evolution of protists disprove them. The first such claim is that the Cambrian explosion 545 million years ago cannot be explained by Darwinian evolution - it was too fast. Farmer and Habura point out that protistan evolution had begun well before then and provided the genomic diversity from which multicellular organisms arose.
The second claim is that no one has ever seen the development of a new species -- that is, a new species that becomes genetically isolated from its parent species. Again turning to protists, Farmer and Habura cite the example of just such a speciation event in which amoebae became symbiotically dependent upon infecting bacteria. If the symbotically dependent amoebae subsequently tried to interbreed with the parent stock, the parent stock died of the bacterial infection. Thus the two became genetically isolated.
Thirdly, IDers also argue that the fossil record does not show transitional species, therefore there is no evidence of one species evolving into another. Farmer and Habura explain that the exquisitely detailed fossil record of protists does exhibit just such intermediate forms.
Fourthly, the two biologists deal with the claim that nature exhibits biochemical changes that simply are too impossibly complex to occur without a designer. They specifically refute ID proponent Michael Behe's argument that the malaria parasite's resistance to chloroquine is too complex to have arisen through natural selection.
Farmer and Habura conclude:
A detailed understanding of protistan biology, therefore, offers scientists and lay persons alike the ability to address current attacks on evolutionary theory, and to refute the claims of ID creationists who insist on invoking supernatural explanations to account for observable phenomena.
Go here to read their excellent article. I also cannot pass up the opportunity to suggest clicking on the youtube mash up of my talk "Attack of the Super Intelligent Purple Space Squid Creators" which I delivered during a debate with IDers from the Discovery Institute.
Via Tree of Life blog.