Molecular Biology Trumps Darwin

Is Evolution Predictable?

To celebrate Darwin's Birthday, Science Magazine ran a special devoted to evolution.  An article by Stern and Orgogozo  entitled "Is Genetic Evolution Predictable" presented a stunning break from neo-Darwinism.  The authors presented a convincing refutation of the  "Blind Watch Maker" argument of Richard Dawkins.  Quite the contrary,  it would appear the "Watchmaker" had his eyes wide open.

Molecular Biology Trumps Darwin

The authors, Stern and Orgogozo,  found that mutations cluster around certain “hot-spot genes,” also called regulatory genes, making evolution somewhat predictable.    The authors were able to predict genome response to environmental stress.  The most compelling case for this comes from parallel genetic evolution.   They cite a number of examples of similar genome changes in different species in response to environmental stress.

"Although mutations are thought to ocurr randomly in the genome, the distribution of mutations that cause biologic diversity appears to be highly non-random."

"Is genetic evolution predictable? Evolutionary developmental biologists have argued that, at least for morphological traits, the answer is a resounding yes. "

You can read Stern's earlier paper here.

References

http://www.molbio.princeton.edu/index.php?option=content&task=view&id=239
David L. Stern PhD

Evolutionary developmental biology

Our research addresses biological problems arising at the interface of evolution and development. How does development evolve on a short time scale, within and between closely related species, to generate phenotypic variation? What are the genetic mechanisms regulating polyphenisms and other dramatic life-history switches? We address these questions using genetic, molecular and developmental techniques. For studying the problem of variation we primarily work with the fruit fly Drosophila melanogaster and closely related species. We study polyphenisms in the pea aphid (Acyrthosiphon pisum).

We found that evolution at the Ubx locus contributes to a difference in this trait between Drosophila melanogaster and D. simulans and this difference appears to be due to evolution of cis-regulatory DNA. This is the first experimental demonstration that evolution of Hox gene patterning is responsible for an interspecific morphological difference.

This is the first experimental demonstration that evolution of Hox gene patterning is responsible for an interspecific morphological difference.

http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=18616572

Evolution. 2008 September; 62(9): 2155–2177.
Society for the Study of Evolution.

The Loci of Evolution: How Predictable is Genetic Evolution?
David L Stern and Virginie Orgogozo

We also found that different spectra of evolutionarily relevant mutations segregate within populations and between species. Interspecific differences in morphology seem to be more often caused by cis-regulatory changes than intraspecific variation.