How can certain animals change their sex at free will? Why can't humans?

Flynn_17

Whatd'ya call Boy George? Apr 03 05, 3:20 PM

elizabethmc

Yes but he can only produce babies with women, whereas some animals which can change their sex can reproduce with both males and females. Ewww. Apr 03 05, 3:34 PM

Flynn_17

Snails, frogs, worms, and sea cucumbers are good examples. Apr 03 05, 3:50 PM

elizabethmc

Miss-read the answer, didn't see 'sea'. I was about to ask 1, why a cucumber was classed as an animal, and 2, how it could change sex. Good job I re-read what you had put. I would have looked silly then. I often look silly. How can snails, frogs, worms, and sea cucumbers change their sex then? Apr 03 05, 3:57 PM

Flynn_17

Something to do with controlling their hormones when there is a large imbalance of genders in an environment. I can't get you a link because my PC doesn't have acrobat reader. Apr 03 05, 4:06 PM

Arpeggionist

Many species of fish, and some of amphibians and mollusks, can control their hormones and change sex at will. This does not mean they do. In most species, there will be one male in a colony, and if anything happens to that male, the strongest female will take its place and change. Reptiles have a more regulated system. With crocodiles and turtles, for example, the sex of a newborn is dependent on the temperature around the egg, once a reptile is born male or female, there's no turning back. Mammals have a stricter genetic system still, with X and Y chromosomes to differenciate the sexes. Apr 03 05, 4:45 PM

Baloo55th

I don't think the ones that do this actually stop and think, 'Hey, I'm going to be a female today!' As Flynn says, they tend to be lower level animals (OK, Wolfie - lower level from our point of view) which don't really exercise true volition in matters like this. Temperature change can trigger some, food availability in others, and some change at different times in their normal development. Flynn, use the 'View page as html' thingy in Google. Or you can get Acrobat Reader free from http://www.adobe.com/products/acrobat/readstep2.html Apr 03 05, 4:55 PM

TheAlphaWolf

"(OK, Wolfie - lower level from our point of view) " huh? sea cucumbers are classified as animals because they are multicellular heterotrophic organisms without a cell wall, with centrioles, etc. (darn... I'm forgetting biology already! lol) I'm also pretty certain that most if not all snails and worms don't change their sex. They're hemaphroditic which means they have both functional male and female sex organs. ... are you sure some frogs can change sex? I've heard of mutant frogs that are kind of strange sexwise but that's because of stupid humans polluting their water. and I don't know about the sex life of sea cucumbers... Apr 03 05, 7:12 PM

gmackematix

I vaguely recall seeing somewhere that oysters chamge their gender depending on the temperature of the water. I'm pretty sure all frogs stick with one gender throughout their lives though. Apr 03 05, 8:15 PM

Flynn_17

Snails are not haemaphroditic by any means. They can either be female, male, or in some cases, can choose to be both and make eggs with themselves. Worms are not only haemaphroditic, but when you cut them in half, you get two worms. Is it just me, or is there something deeply unsettling about that? I was wrong about frogs, it's the lower level amphibia, but the Suriname Toad gets up to some pretty odd sexual shennanigans. No eyes, children live in holes on her back, and she can be male and female, whichever 'she' chooses. Apr 04 05, 6:44 AM

TheAlphaWolf

snails and worms ARE hemaphroditic. when two snails meet (most of them anyway... my water snails don't seem to have any and instead take turns... i guess) they insert each other's penises into an area right behind the head and later they both lay eggs. when two worms meet, they align each other in such a way so that they each give the other sperm. hemaphroditic and transexual are two different things. the "toad" you're talking about does have eyes. they're just small Apr 05 05, 5:44 PM