Heat can overrule chromosomes to determine sex in bearded dragons - Polidicks

[QUOTE]At room temperature, a bearded dragon’s sex depends on two chromosomes. If they have two Z chromosomes, these lizards develop as males. Those with a Z and a W become females. But raise the thermostat up a few notches, and something different happens. If a clutch of dragon eggs are incubated at 34 degrees Celsius, their bodies ignore the usual instructions from their sex chromosomes. Even if half of them are genetically male (ZZ), all of them will hatch as females. Clare Holleley from the University of Canberra found some of these “sex-reversed” ZZ females in the wild, and bred them with the usual ZZ males. All the offspring from these crosses should have two Z chromosomes, so you might guess that all of them would turn out male. You’d be wrong. In fact, their chromosomes didn’t matter at all. Instead, their sex depended entirely on the temperature at which they are incubated. Warm clutches produced females; cooler ones produced males. “This makes me think of the statements I’ve seen about trans individuals not being “truly male” or “truly female”, because of their (presumed) set of sex chromosomes,” she adds. “This research tells us that even with chromosomal sex determination, exceptions occur all the time. In the bearded dragon, the exception may even be a benefit, as ZZ females lay more eggs that ZW females. This tells us that we’re thinking much too simply if we say with confidence that only XX is female and XY is male.” [/QUOTE] [url]phenomena.nationalgeographic.com/2015/07/01/hot-wild-dragons-set-sex-through-temperature-not-genes/[/url]

Hot.

"I was just too hot to be male"

Awesome. This kind of make sense actually now that I think of it with my beardie breeding

Evolutionarily, that sounds like a fantastic fallback mechanism. Being cold-blooded, if they find themselves in colder temperatures more frequently (resulting in more females), they increase their chances of an adaptation to the cold quicker.

[QUOTE=Bradyns;48147191]Evolutionarily, that sounds like a fantastic fallback mechanism. Being cold-blooded, if they find themselves in colder temperatures more frequently (resulting in more females), they increase their chances of an adaptation to the cold quicker.[/QUOTE] Cold makes more males though...

One of the comments mentioned an similar study done on another species of reptiles, the Tuatara. It's the same for Tuatara where sex seems to be based on temperature, but it's reversed from how it goes for bearded dragons. (link for those interested: [url]http://researcharchive.vuw.ac.nz/xmlui/handle/10063/155[/url] )

I don't really see the point of the trans bit. This is more about biological sex not really gender. Might help out the lizardkins though. Oh I should've read this more clearly at work, I thought the temperature determined/changed the chromosomes, not completely voided them.

Congrats bearded dragons, you're never going extinct. That's a really, really good evolution trait to have.

[QUOTE=mr apple;48147250]Congrats bearded dragons, you're never going extinct. That's a really, really good evolution trait to have.[/QUOTE] Unless the world cools down and its a lizard flavoured sausagefest or heats up to the point where the gene pool stagnates from having very few males.

We've known this for a while with geckos and gators. Didn't know it affected beardies, too.

See transgendered individuals aren't unnatural abominations! But really this is an interesting result of egg laying species, and a scary consequence of global warming

Didn't we already know this about alligators and crocodiles?

That's really neat, is this a trait among a majority of lizard species? As other posters have mentioned other lizards that do this.

[QUOTE=Dysgalt;48156257]That's really neat, is this a trait among a majority of lizard species? As other posters have mentioned other lizards that do this.[/QUOTE] It is. I was reading this and all I was thinking "How is this news? We already know it."

[QUOTE=Dysgalt;48156257]That's really neat, is this a trait among a majority of lizard species? As other posters have mentioned other lizards that do this.[/QUOTE] Oh ya. The way some non-mammalian species have their gender assigned can be very curious, or weird, or not at all random.