11-14-2007, 12:08 AM
Lizmom23 Wrote:
I think that Aspergers represents the "in-between" state of NT and classic autism. Imagine, for example, that NT carry two copies of a master sensory gene (SS). At some point, the gene aquired a mutation (M). Two copies of the mutated gene (MM) produces autism. One copy of the original gene, and one mutated one (SM) produces Aspergers. Clearly, autism is not going to increase reproduction and will not be selected for by natural selection. BUT, as it the case with a number of recessive diseases, the heterozygous condition confers an advantage, therefore the mutant gene stays around. Two copies of the sickle cell trait is lethal. But one copy reduces malarial infection. Two copies of the cystic fibrosis gene is lethal. But one copy confers resistance to tuberculosis. So two copies of the yet-to-be determined mutated sensory gene cause severe problems, but one copy results in advantages - and therefore stays in the population. I'll go further and say that as we have moved from a society of hunter/gathers/farmers/etc to a society where security is derrived from economic success, benefits from Aspergers type is increasing, producing even more ASD in the population.
very well put!

