Posted by alexandra_k on September 27, 2006, at 5:23:36
In reply to Re: genetics of schizophrenia, posted by SLS on September 27, 2006, at 2:32:04
> The other thing I forgot is that if schizophrenia doesn't develop until after the age of successful breeding, it will remain in the population. It is unusual for it to appear before age 18. It occurs most often in the mid 20s. Therefore, an individual will breed successfully before developing the disorder and will transmit the genes.
Yeah.
> For right now, the majority of scientists regard schizophrenia to be a complex, multigene disease that is highly heritable.Depends on what kinda scientists... The geneticists certainly think the disorder is genetic :-)
> To talk about a single gene or haplotype and use it as a point to try to make or break an argument regarding the genetic nature of schizophrenia might be difficult. It could make the argument, but it couldn't break it.
Well...
It is an empirical matter...The term 'gene' is ambiguous. I think it tends to be used in two ways. In one sense a gene is a combination of allels. (Is that right?). But in one sense the notion of a gene is a localised part of a chromosome. In the other sense the notion of a gene is more abstract... Something along the lines of a placeholder for whatever allels.
If you talk about the 'schizophrenia gene' you might mean that there are a bunch of allels somewhere on the chromosome and however those allels are is necessary and sufficient for schizophrenia.
Or you might mean that surely people must develop schizophrenia because of the way their allels are... And the 'schizophrenia gene' can be multiply realised by all kinds of allels at all kinds of locations.
Griffiths talks about 4 (I think) different meanings of innate (in the sense of genetic versus environmental). He doesn't think we should talk about things being genetically determined / innate because the way genes express is dependent on the environment. He distinguishes 4 things we might mean (of varying strengths).
I can't remember what they are...
I'm tired.
I'm sorry.I don't really know anything about genetics / biology
But I guess I'm gonna have to learn...
poster:alexandra_k
thread:689461
URL: http://www.dr-bob.org/babble/20060927/msgs/689539.html