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OP
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"A female crocodile or alligator doesn't sit on her eggs to keep them warm. She covers them with soil and vegetation, and as this material starts to "compost," the nest mound heats up. But don't think the temperature of an alligator nest is a trivial matter. The nest is made with just the right mixture of mud and vegetation to create a precise range of internal temperatures. Why so specific? Because the sex of hatchling crocs and gators is determined by the temperature within the nest! Eggs incubated at around 89 degrees Fahrenheit produce females, while those at temperatures below 87 degrees produce mainly males. In a well-constructed croc nest the eggs on top will be a few degrees cooler than those closer to the bottom, and -- VOILA! -- when the babies hatch there are usually an equal number of males and females.
This phenomenon (known as temperature-determined sex) is amazing, but it's not unique, also occurring in turtles and lizards. The sex of human babies, however, is not known to be affected by the temperature of their parents' compost heap."
eNature.com
Now that's a mouthful to contemplate...
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Carpal Tunnel
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Carpal Tunnel
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And croc mothers do not just leave hatchlings to fate, as do turtles. They stay in vicinity of nest to drive predators away. I saw TV program with mother gently holding little ones in her mouth, purpose not entirely clear. Perhaps to scavenge her teeth for remnants of last meal?
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Joined: Sep 2001
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Carpal Tunnel
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OP
Carpal Tunnel
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And how 'bout croc fathers? What do they do? Are they like the hummingbird fathers who perform the great escape?
And, by the way, this was the first time (thread starter post) that I've ever seen compost used as a verb. Live and learn...
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Carpal Tunnel
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Carpal Tunnel
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Eggs incubated at around 89 degrees Fahrenheit produce females, while those at temperatures below 87 degrees produce mainly males.Hmm...so the females are hotter than the males. The sex of human babies, however, is not known to be affected by the temperature of their parents' compost heap."Evidently.
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old hand
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old hand
Joined: Jul 2000
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Concerning animal gender, I found it interesting to read recently that in birds the y-chromosome is carried by the female, opposite from most other animals, humans included, of course.
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Carpal Tunnel
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OP
Carpal Tunnel
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And why does the female bird carry the Y-chromosome?
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enthusiast
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enthusiast
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Are you suggesting that hummingbird ladies are more Y's than human ladies, sir???
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old hand
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old hand
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And why does the female bird carry the Y-chromosome?
I don't know, but butterflies are the same way. All humans (and most other animals, I assume) start out in embryotic form as females and then at some point in all of those cell divisions, the male y-chromosome kicks in. The book (Genome, Matt Ridley) says that the sex genes are the most volatile of the chromosomes. The x and y are constantly fighting with each other (seriously). Certain "improvments" in the x are deleterious to the y, and the y has been shedding excess genetic material for a long time. That's why it's so much smaller than the others. With all of this changing going on between the two, it's a fair assumption that it was all switched at some point, or that birds and the ancestors of mammals emerged from the asexual goo on opposite sides of the gender coin. But really, I don't know.
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Carpal Tunnel
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the word crocodile, curiously, is, at it's root, is related to the root word for sugar!
crocodile comes to english, from ME, and L. The ME cocodrille, is from MF, cocodrillus, an alteration of the latin crocodulus, which came from the Greek, krokodilos, (lizard/crocodile) from the greek roots of kroke (shingle, pebble) + drilos, worm.
the kroke of the greek is related to the sanskrit sarkara which also mean pebble(pebbles)
by an other route, sarkara moved to persian as shakar, and then to arabic as sukkar, and then dispersed throught italian and french (it still is surce in french)and into english as sugar!
the pebble meaning has to do with sugar's gritty quality, (very evident if you have ever spilled some!)and the same root shows up again in seersucker, (one of Anu's words with interesting etymologies) seersucker fabic comes from the persian, meaning milk and sugar.
who would have thought, sugar, seersucker, and crocodile, all related words at the root meaning? and are there other words with as much grit!
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Carpal Tunnel
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OP
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Seersucker...milk and sugar...what a lovely thought! Now I'll look at those old white-haired Southern gentlemen in their seersucker suits and will think, "You're milk and sugar, old men in seersucker, sitting there nodding your heads in your pews on Sunday mornings...milk and sugar..."
Do you think the crocs were called so because of the bumpy texture of their skin? Gritty?
Thanks, of troy, for this information! DubDub
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