a gene for X

Pavel

Hi, the following is from Steven Pinker's debate (against Rose). Can somebody please translate this into more understandable language. I know what allele and average and all the individual terms mean, but I just don't get the concept and I want to know what evolutionists mean when they say "a gene for X":

"...What I mean by "a gene for X," and what ALL evolutionary theorists mean by "a gene for X," is simply a gene that, in comparison with its alternative allele, averaged over the other genes that it appears with in bodies, and averaged over the environments in appears in, probablistically leads to more behavior X-say, being solicitous to one's children. That's all that "a gene for X" means, and that definition is completely consistent with all of the arguments about genetics in Lifelines..."

Thank you in advance.

Moonbear

X is being used like a variable here. It can be anything. It's just a way of describing any gene rather than referring to a specific one. Usually, you refer to a gene in terms of the phenotype observed for the dominant allele (for example, if you have a particular gene with an allele for black hair and an allele for blonde hair, and black is the dominant allele, you would say it's the gene for black hair, even when referring to someone with two recessive alleles who has blonde hair...particularly useful when there are multiple genes for hair color).

Does that help?

jim mcnamara

In simple terms: If you have several alleles at one locus on a chromosome, and after looking at many people (or whatever species) with all the possible allele combinations, one allele stands out as having more of an effect on some observable than its cousins.
It is then called a 'gene for X' -> X being the observable.

Since humans can adapt an awful lot to the envrionment, the envrionment effects may override an allele because of the human response to other conditions. This makes it hard to come out with absolute statements about perfect relationships between genes behavior, for example. And why twin studies have been done.

Pavel

Ah, that's it. Makes sense now. Thanks!

Moonbear, I appreciate your help too.

Pavel.