Actually, wouldn't you need a Y chromosome to get a son? They're not randomly lumping DNA bits together in a sperm, they're producing a sperm from a female stem cell.
I find it funny though that people immediately think of an all-female world when hearing such news. I don't see any reason why this should happen.
I was wondering, is the whole, gay is in the genes true? Follow up question: if it is true, would passing on the genes of two lesbians most likly make the child lesbian? If so, then I think this may meet some conflict.
It's not just the Y chromosome that determines maleness. Lots of other factors come into play such as the SRY gene and the environment. There are men with XX.
It's called de La Chapelle Syndrome haha. There are also all sorts of weird combinations such as XXY (Klinefelter's Syndrome) and XO (Turner's Syndrome). But I have honestly no idea if two women can have a boy.
It's called de La Chapelle Syndrome haha. There are also all sorts of weird combinations such as XXY (Klinefelter's Syndrome) and XO (Turner's Syndrome). But I have honestly no idea if two women can have a boy.
Yeah ok. Genetic, physical and mental gender can all vary and I guess almost all combinations can occur, plus a few other weird syndromes as you said. But those are syndromes, usually the exception. Let's say that in general, two women will give birth to a girl.
Even if they could only have a daughter, it would be theirs. Like, properly. I'd settle for the ability to have one gender with my partner than none.
And I think it's their right to have their own child. I just see minor problems ahead with the financial aspect (insurances pay or not?), and it certainly won't help the full adoption centers; but it would be highly unfair to go on shifting the problem of adoption centers on to homosexual couples.
I was wondering, is the whole, gay is in the genes true? Follow up question: if it is true, would passing on the genes of two lesbians most likly make the child lesbian? If so, then I think this may meet some conflict.
It all depends on the regulation of the involved gene(s). There are probably more than one gene involved, and only because you have the blueprint doesn't mean you'll build all of it. My guess is children of a lesbian couple simply have a higher probability of being homosexual.
Yeah ok. Genetic, physical and mental gender can all vary and I guess almost all combinations can occur, plus a few other weird syndromes as you said. But those are syndromes, usually the exception. Let's say that in general, two women will give birth to a girl.
Point being no it's not just the XY chromosomes at work.
Teaching a summer school course on evolutionary genetics and its social implications to students from all over the world is instructive in many ways. One of the most striking has been to make me aware of common misconceptions about sex-determination. Many students seem to think that biologically sex is simple: itâs determined by the fatherâs sperm. An X-sex-chromosome-bearing sperm fertilizes an always-X-carrying-egg to make it female (XX), a Y-bearing one makes it male (XY).
The truth, however, is more complicated and more intriguing. One problem is the fact that the Y-chromosome is tiny by comparison with the X and only produces 20-odd proteins, mostly concerned with highly male-specific functions like sperm-production. The X, by contrast, has almost 1200 genes, with at least 150 implicated in intelligence and cognition. Look at it this way: if all the genes for being male were on the Y, no woman could ever have a beard! But because hardly any genes related to maleness are on the male chromosome, the vast majority must be on autosomes (the 22 non-sex chromosomes) or the X, which are of course carried by females. Such masculinizing genes could easily be turned on accidentally, explainingâ"and indeed predictingâ"bearded ladies.
But this is just the start of it. Because X-chromosome genes spend twice as much of their evolutionary history riding in female bodies rather than male ones (because mammalian females have two Xs and males only one), X-chromosome genes are selected to benefit females twice as often as they are selected to benefit males. Indeed, if an X-gene conferred at least twice as much benefit to a womanâs reproductive success as it inflicted costs on a male carrierâs, natural selection could not fix it. For example, there is now good evidence for genes on the X that increase the fecundity of their female carriers but make their male carriers homosexual. To the extent that such homosexual males may be feminized, the evolutionary insight explains the apparent paradox: sex-chromosome genes can be in conflict, and what is good for one sex is not necessarily good for the other.
The most striking case is DAX1: a gene named after a Star Trek character. This is an X-chromosome gene that competes for control of sexual development with SRY, the male Y-chromosome sex-determining gene in mammals (which develop as females if SRY is not expressed). Duplication of DAX1 makes XY males develop as females and it has been described as an âanti-testisâ rather than âpro-ovaryâ gene.
But thatâs not all. According to a provocative theory proposed by Valerie Grant, the mother may also play a critical role in determining which kind of spermâ"X- or Y-carryingâ"she allows to fertilize her. According to her theory, more dominant women with higher levels of testosterone are more likely to conceive sons, and less dominant ones with lower levels, daughters. Although the details remain controversial, the idea is a sound one. Contrary to what many people think, biological sex-determination is not simple and does not necessarily put one sex or the other in charge. The truth is that evolution is ultimately a question of some genes getting into the future at the expense of others, and consequently genetic conflict, not simple sex-chromosome determinism, is what explains sex-determination. Indeed, as I argue in The Imprinted Brain, genetic conflictsâ"including those related to sex-determinationâ"almost certainly explain both mental health and illnessâ"and arguably do explain the striking sex differences in the incidence of psychiatric illness. At the very least, these evolutionary and genetic insights give the lie to the common belief that biological sex-determination is crude and simple, and that it predicts clear-cut sex differences.
