Monday, April 12, 2010

Why darwinian fundamentalism and genetic determinism?

Once again we return to the subject of darwinian fundamentalism and genetic determinism, something we have blogged about frequently before (here, for a start).  t's a subject that we write about a lot because this worldview is so pervasive and can have such destructive effects.  But if that's true, why does such a fervent clinging to darwinian fundamentalism and genetic determinism still persist?

Why such fervent clinging to darwinian fundamentalism in spite of what we know?
Darwinian fundamentalism is the belief that organized traits have to get here by a history of some material causes, not by pure chance, and that the major molding force we know of is natural selection.This view is held by many in spite of the fact that we know that selection is not usually a 'force', there are usually multiple ways to be successful at any given time, and most traits are due to many contributing genes. Pruning away what simply doesn't work is undoubtedly important, and is selection, but it isn't natural selection in the Darwinian sense: it need not involve competition, resource shortages, or population pressure. And it's not fine tuning.

Chance effects manifestly occur. It is probably typical that there are many roads to success (i.e., to reproduction), most of them not what might be deemed the very best (given this, as we say in The Mermaid's Tale, a more accurate description of who succeeds would be 'failure of the frail' rather than 'survival of the fittest'). Among roughly comparable ways to do OK, the way one takes is a matter of chance, and the differing ways will change slightly over time. There are other ways to mold traits such as (but not restricted to) organismal selection where individuals choose their preferred environment, and niche construction where they make it.

All of these are perfectly in line with what we know about genomes, phenogenetic relationships (between genotypes and phenotypes in individuals), and evolution as population history. To say that something organized can be here without having been fine-tuned by selection, or without some specific selective reason, is not anti-evolutionary nor non-causal, nor mystic! There is no need to invent adaptive scenarios for every trait!

Why is there such fervent clinging to genetic determinism?
The fact that genetic mechanisms are involved in essentially all biological traits does not mean there must be a specific genotype (or even a tractable subset of genotypes) that determine or mandate a trait. Chance in many manifestations, and the effects of non-genetic aspects of life combine, often in different ways in each individual to produce traits. Each instance may involve a different genotype (perhaps at a great many genes), but even knowing that genotype may not lead to useful predictive ability. That organized traits can be here without having been genetically determined in the usual connotation of that phrase is not non-materialistic, nor non-causal, nor mystic!

To insist that only one particular explanation is consistent with legitimate materialistic science is a deep misunderstanding of what we know about evolution, and of what we know about genetics.

The acceptance of the role of chance in evolution is treated as heresy in some circles. It's a clinging to darwinism as religious fundamentalists cling to the Bible. But, so much has been learned in the 150 years since Darwin that it's bad science not to question, and build upon Darwin's ideas. Odd that he's so often treated like Jesus! It's not questioning evolution, it's strengthening it.