Wednesday, June 10, 2009

Epigenetic Inheritance: Can Evolution Adapt?

Given how routinely evolution fails to explain biology, it is remarkable that scientists still believe in the nineteenth century idea. One of the many problem areas is adaptation. Evolution holds that populations adapt to environmental pressures via the natural selection of blind variations. If more fur is needed, and some individuals accidentally are endowed with mutations that confer a thicker coat of fur, then those individuals will have greater survival and reproduction rates. The thicker fur mutation will then become common in the population.

This is the evolutionary notion of change. It is not what we find in biology. Under the hood, biology reveals far more complex and intelligent mechanisms for change, collectively referred to as epigenetic inheritance. You can read more about the challenge that this form of inheritance poses for evolution here. The take home message is that adaptation is routinely found to be not blind, but rather responsive to environmental pressures. The fur becomes thicker not by accident, but via cellular mechanisms responding to a need.

There is still much to learn about this phenomenal built-in adaptation capability, but it now is clear, and has been for several years, that epigenetic inheritance is a dramatic departure from evolutionary expectations. Indeed, this sort of adaptation is closer to the ideas of the long disgraced French naturalist Jean-Baptiste Lamarck (1744-1829). Lamarck's idea was that offspring inherit traits or characteristics that were acquired by the parents. Although epigenetic inheritance is far more complex than anything Lamarck imagined, he was remarkably close to what is now being discovered. You can see a recent review of what has been learned here. Only a few years ago positive references to Lamarck drew heated response. Such ideas were not tolerated. Now his name appears regularly in the epigenetics literature.

This leaves evolutionists in an awkward position, to say the least. For years many have been resisting these evidences. I raised these evidences in a debate once and the evolutionist flatly denied any such thing. The problem is that such intelligent adaptation capabilities suggest design, not accident. Evolution is left with the unlikely explanation that evolution constructed elaborate adaptation mechanisms so that evolution could then occur--hardly the obvious explanation. It is yet another example of how evolution is failing to explain biology.