Wow: another terrific article from The Panda’s Thumb, which is quickly becoming one of my favorite destinations on the web. This article is discussing some of the interesting research surrounding prions, self-propagating variants of certain proteins that are the infectious agents behind diseases like scrapie, bovine spongiform encephalopathy, and variant Cruetzfeld-Jakob disease. What’s really interesting is that they may enable a form of Lamarckian evolution where traits which are not encoded genetically but are rather acquired through infection can be passed to offspring, subject to normal natural selection.
In certain conditions, for instance when an organisms recurrently but unpredictably encounters a specific, strong selective condition, prion systems may result in the environmental induction of adaptive, acquired heritable phenotypes.
At this point, we don’t have any bona fide examples of this actually happening, but in principle it’s possible. Moreover, this model provides a real, testable mechanism to explain such a phenomenon, should it occur (scientists don’t mind testable mechanisms and hypotheses, even when they are “heretical”).
Nothing stimulates science better than a good heresy, I always say.