Womb temperature determines the sex of the offspring in many reptiles. Why not in humans?

Credit: Marta Pucci
Credit: Marta Pucci

Temperature controls sex determination, in all crocodilians, most turtles, many fish, and some lizards, according to organismal biologist Karla Moeller at Arizona State University. Within a specific window of time during the embryonic development of these animals, heat or cold can influence the production of sex hormones, which in turn can sway a hatchling’s fate.

All known species with temperature-dependent sex determination are both oviparous, or egg-layers, and cold-blooded, meaning their body temperatures change with that of their surroundings. However, humans are neither of those things.

As such, “temperature-dependent sex determination in humans is not very likely because you would need, at a minimum, two different body temperatures — one that would trigger female development and one that would trigger male development,” [biologist Diego] Cortez said. “But the human body is always at 37 degrees Celsius (98.6 degrees Fahrenheit).”

ADVERTISEMENT

Follow the latest news and policy debates on agricultural biotech and biomedicine? Subscribe to our newsletter.

For temperature-dependent sex determination to exist in humans, [geneticist Jennifer] Graves suggested one possibility is that we somehow become poikilotherms — that is, unable to control our body temperature — much like the naked mole-rat. Another possibility is that instead of live births, we were to somehow lay eggs like a platypus, she added.

Read the original post 

Related article:  ‘Great ape-like brains’: Early humans who first ventured out of Africa 1.5 million years ago had 'monkey brains'
Outbreak Daily Digest
Biotech Facts & Fallacies
GLP Podcasts
Infographic: Here’s where GM crops are grown around the world today

Infographic: Here’s where GM crops are grown around the world today

Do you know where biotech crops are grown in the world? This updated ISAAA infographics show where biotech crops were ...
News on human & agricultural genetics and biotechnology delivered to your inbox.
glp menu logo outlined

Newsletter Subscription

* indicates required
Email Lists
Send this to a friend