Search results

@asdfasdf333 It's not as clear cut as that. A sperm will carry a copy of either the x or the y chromosome from the male (at least for humans). However the environment they enter into, such as the female's temperature levels, can determine which sperm will more likely make it to the egg. I also...

@elam84 I'm curious how fraternal twins come into play in any of the research, if it makes any difference at all. As well as miscarriages. If there is a pattern or observable reasoning then it would need to account for such things. Anecdotally I had fraternal boys (my husband's family is VERY...