tag:blogger.com,1999:blog-10557263.post8475988239376951121..comments2024-01-26T10:20:37.836+00:00Comments on Diary of a Goldfish: Sexuality & Evolutionary Non-MysteriesThe Goldfishhttp://www.blogger.com/profile/15213378454070776331noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-10557263.post-89071386263754606872014-03-12T14:12:13.585+00:002014-03-12T14:12:13.585+00:00Thanks Louna - sorry it took so long to reply to y...Thanks Louna - sorry it took so long to reply to your comment. <br /><br />I think I'd still define Down Syndrome or any chromosomal disorders as genetic because chromosomes are made out of genes, but you're right that any genetic mechanism that might be responsible for homosexuality would be very very different from the mechanisms involved in Down Syndrome. The Goldfishhttps://www.blogger.com/profile/15213378454070776331noreply@blogger.comtag:blogger.com,1999:blog-10557263.post-60280053890616916162014-02-20T14:55:25.844+00:002014-02-20T14:55:25.844+00:00While I agree with the general gist of you post, I...While I agree with the general gist of you post, I must take issue with the description of Down Syndrome as a genetic. It is chromosomal, caused as you write by an extra copy of a whole chromosome, and not by a genetic mutation. Trisomy is quite common - the only reason why most trisomies, apart from Down Syndrome and trisomies of the sexual chromosomes, are really rare, is because most cases result in miscarriages - and the mechanism is simple enough for people without trisomy to produce children with trisomy again and again, and with a limited number of chromosomes, Down Syndrome is bound to "spontaneously" appear over and over again. With genetic mutation the variety is much greater, with about 3 billion base pairs that can be affected by replacement, deletion or duplication, usually in whole groups. There, the chance of the same mutation, or the same effect, appearing spontaneously over and over again is much smaller, so common genetic variants are much more likely to be hereditary than common chromosomal variants.Lounahttps://www.blogger.com/profile/11031075401203936622noreply@blogger.com