Sunday, October 19, 2008

Genomics, Disease, Evolution

The lineage of many of human genetic diseases is thought to stretch back pretty far in our evolutionary history. Chimpanzee maybe? Nope, a little farther back.

A new study demonstrates that genetic diseases like Huntington disease have their origins in primitive life forms. Quoting the New Scientist article "By the time zebrafish evolved from a common ancestor of fish and humans about 400 million years ago, 98 percent of all our disease genes had already appeared." Many diseases are even more ancient and are shared with bacteria. So not only do some bacteria make us sick now, some also gave us genetic diseases millions of years ago. Not a good day for bacteria public relations.

Using a statistical analysis called phylostratigraphy, Tomislav Domazet-Loao and colleagues demonstrated origins for genetic disease in humans by tracing the last common shared ancestor for the disease gene. They found a surprisingly old lineage for the vast majority of genetic diseases, suggesting that most genetic diseases affect fundamental cellular processes.

This research will have important implications for understanding disease mechanisms and for the ways in which scientists study genetic diseases. It is a fascinating glimpse of the possibilities of the new field of genomics.

And it is one reason, among many, why it is preferable to have leaders (particularly executive branch candidates) who believe in evolution. I threw up a little writing that.

(image credit: benzopyrene DNA adduct, Zephyris,