Species that are able to change gender due to the environment have been know for a while now, like fishes and frogs. Because there are so few males in the population some females can turn into males from changes in hormones and other things that happen in their body.
So I was wondering if an animal changes sex does it also change its chromosomes? That sounds unlikely, but if a population of frogs only ended up with females and the females changed to males wouldn’t the population only be able to produce females for the rest of its existence because there are no Y chromosomes.
Not all species determine gender the way humans do, by the loss of a piece of one chromosome. And even if they do, chromosomes aren’t always X and Y. I think in birds they have W and V. I’m sure there are other variations
That’s pretty rare. Most species change gender simply because of age and size. They start out male, and then become female once they reach a certain size.
No.
These species don’t determine sex primarily by chromosomal makeup, if at all. Sex is determined by hormones, and the hormomes are determined by environment, the chromosomal makeup of all individuals is identical. While in some cases sex changes can only run one way, ie male to female or vice versa, in essence if an individual has the right hormonal cues then it *is *that sex.
Sequential hermaphrodites start off as males in some species but as females in others. In some cases the trigger for the switch is the opportunity to replace a member of the other sex.
They’re called W and Z. Those are just names; the important point is that females have two different types of sex chromosomes (ZW) and males have two of the same type (ZZ), whereas the reverse is true in humans.
Re Wiki and my memory, platypuses have something like 10 sex chromosomes but wiki goes on to add that the platypus lacks a mammalian sex determining thingy so we still don’t know how the humble platypus decides. (It really does seem like one of the world’s weirder creatures)
It’s probably not worth pointing out, but I’m going to anyway, that even though fruit flies do use an XY system, it works in a very different way than ours. Mammals have a specific gene on the Y chromosome (SRY) that is the key to being male. Fruit flies measure the ratio of X chromosomes to autosomes to decide, allowing us to make weird intermediate or extreme sexes.