Wednesday, February 08, 2006

Evolve complex traits? That's unpossible!

Researchers evolve a complex genetic trait in the laboratory:
Duke University biologists have evolved a complex trait in the laboratory -- using the pressure of selection to induce tobacco hornworms to evolve the dual trait of turning black or green depending on the temperature during their development. The biologists have also demonstrated the basic hormonal mechanism underlying the evolution of such dual traits.

Their experiments, they said, offer important insight into how complex traits involving many genes can abruptly "blossom" in an organism's evolution.
By selecting for polyphenic expression of pigmentation, the researchers were able to produce caterpillars which change color when exposed to heat. The caterpillars being studied are related to a species which undergoes this sort of change naturally. Evolutionary logic suggested that it ought to be possible for the related species to evolve that ability, since the basic pathways ought to be shared due to common ancestry.

They were right. Science wins again.