Posted by: Dan | October 10, 2007

Genes and Cellular Divisions of Labor

For all those evolution-denialists out there, Sean B. Carroll has a new study out, demonstrating again a ~37-year-old concept – gene duplication as a mechanism by which natural selection generates novelty. In A gene divided reveals the details of natural selection:

“One source of newness is gene duplication,” says Carroll. “When you have two copies of a gene, useful mutations can arise that allow one or both genes to explore new functions while preserving the old function. This phenomenon is going on all the time in every living thing. Many of us are walking around with duplicate genes we’re not aware of. They come and go.”

In short, says Carroll, two genes can be better than one because redundancy promotes a division of labor. Genes may do more than one thing, and duplication adds a new genetic resource that can share the workload or add new functions. For example, in humans the ability to see color requires different molecular receptors to discriminate between red and green, but both arose from the same vision gene.

More examples: the diversification of myosin, and phosphotidylinositide-3 kinase (PI3K) isoforms, and kinase domains kinases in general.

The full Nature article can be found here.

  • A gene divided reveals the details of natural selection – EurekAlert
  • Hittinger CT, Carroll SB. Gene duplication and the adaptive evolution of a classic genetic switch. Nature 449, 677-681 (11 October 2007) | doi:10.1038/nature06151
  • Louis EJ. News and Views: Evolutionary genetics: Making the most of redundancy. Nature 449, 673-674 (11 October 2007) | doi:10.1038/449673a
  • Ohno S. Evolution by Gene Duplication (Springer, New York, 1970)


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