Darwin Still Rules, but Some Biologists Dream of a Paradigm Shift – New York Times.
An article in the NY Times from about 18 months ago but it makes an interesting point – our current Neo-Darwinian theory of evolution gives no account of the arising of new bodily forms that living beings take. What Neo-Darwinism does incredibly well is explain how the spontaneous variations in the genetic code, and thus physical forms and behaviours, become widespread in a population – via natural selection operating on individual members of the population, causing some to multiply their genomes and progeny, and others to fade from prevalence.
But how do those variations of form that natural selection acts upon arise? How do we explain Nature’s creativity in producing organisms from genetic changes? That creativity is being increasingly detailed by developmental biology via the study of genetic expression, but we don’t have an account of why particular variations of form arise instead of others. Just how does cellular behaviour – what DNA programs for – turn into limbs, organs, nerves and behaviours? Increasingly sophisticated computer modelling, selective gene targetting, and marking of in vivo genetic expression so development of particular tissues can be tracked is allowing us to open up Nature’s hood and check out the engine underneath. A flood of genetic expression and lineage data is being extracted from the natural world, but mystery upon mystery remains. That drives the quest for understanding forward and bedevils us with puzzles…
What a grand time for biology!
But what constrains its creativity? What organises the genetic networks? What’s the internal logic of genomes? Are there higher organising principles that would allow future forms to be “predicted” under various environmental stresses? Inquiring minds want to know.