Wednesday, December 20, 2006

Evo-devo

If I were a young scientist starting out today, I would seek out the exciting new field of evo-devo, where evolution and developmental biology intersect.

Scientists have long been interested in phylogenesis -- the evolution of organisms over geologic time -- and ontogenesis -- the development of a single organism from its earliest stage to maturity. Evo-devo looks at the genetic processes that control development of plants and animals in hopes of establishing how these processes evolved.

I don't pretend to know much about this stuff, although I try to keep up with the drift of things. But I look at an illustration like this one in the November 17, 2006, issue of Science, showing possible stages in the evolution of gene regulatory networks of metazoans (multicellular animals with differentiated tissues), and a little bell rings deep in my brain that was established a half-century ago when I was studying electrical circuit theory as a young engineer.


Look at the language on the diagram (click to enlarge). "Gene battery subcircuits." "Regulatory state circuits." "Address." "Kernel." "Progenitor fields." All terms from Eric Davidson's new book, The Regulatory Genome: Gene Regulatory Networks in Development and Evolution, all adapted from electrical engineering or computer science. The connection is more than metaphorical. The gene regulatory system does indeed function much like the operating system of a computer. And just as subprograms are often conserved as a computer operating system evolves, so genomic subprograms are conserved in biologic evolution.

It would be interesting to see a diagram similar to the one above (on a very much more complex scale) for the evolution of, say, the Apple operating system over the 30 years since Steve Jobs sold the first Apple I, and compare that diagram to the evolution over 600 million years of the gene regulatory system of the fruit fly.

The sequencing of the genomes of many species of plants and animals and the rapid acceleration of computer power will converge into what will surely be the most exciting science of the next half-century. And -- you can bank on it -- intelligent design will have exactly zero role in the equation.