Posted on 06/16/2008 7:56:28 PM PDT by Kaslin
If you're an expectant mother who likes to stand up for yourself, you could soon be cuddling a newborn son.
Feisty women are more likely to give birth to boys than girls, according to scientists.
High levels of testosterone in the womb - apparently evident in more aggressive women - provide a much better environment for the sperm coded to produce boys, they claim.
But fiery females whose hearts are set on a daughter shouldn't throw out those pretty pink baby dresses just yet.
So far the correlation has been proved only in tests on animals.
The scientists who carried out the research, however, expect the same outcome will be seen in humans.
And those girls with an aggressive streak won't be the only ones expecting boys.
Testosterone levels rise in women under stress so those feeling anxious could also be in line for sons, according to the scientists. At the most basic level, it is the type of sperm which decides whether a child is a boy or a girl.
If the sperm which fertilises the egg contains an X chromosome, a girl will be born; but if it is a Y chromosome, a boy is the result.
However the environment within a woman's womb affects the likelihood of different types of sperm making it to the egg first.
This study appears to show that - at least in cows - a higher than average amount of testosterone in the womb makes it easier for Y-bearing sperm than X sperm.
Testosterone levels in women are linked to traits of maternal dominance and aggression.
To prove the link, scientists in New Zealand extracted the follicles from cow ovaries, which contain eggs. The follicles were tested for levels of testosterone, and then the eggs were fertilised in the lab.
The sexes of the resulting embryos were ascertained and then compared with testosterone levels in the follicles from which they came.
Team leader Dr Valerie Grant, of Auckland University, said: 'Results showed that follicular testosterone levels were significantly higher for subsequently male embryos.'
She said the fact that testosterone levels rose in women after experiencing chronic stress could mean that they were more likely to have boys after a nerve-racking experience.
Scientists had previously thought sex selection was a matter of chance based simply on which sperm reached the egg first.
But this could not explain how some animals had managed to change the ratio of male and females born as they had evolved.
If this were true Chelsea would’ve been born Arnold Schwarznegger.
“Scientists say”
“Experts say”
What are their names Dilbert!
And, with higher levels of intrauterine testosterone, if you don’t get a boy, you’ll get a girl that looks like one.
Tell it to Anne Bolyn.
What if she’s sassy?
Total and utter BS.
Most anyone at all that I know would say either to my face or behind my back that I am "feisty" and I am the mother of 3 girls, besides, it's the father who determines the sex of the baby.
End of story.
Sometimes genotype and phenotype do not match. With sufficient prenatal testosterone (not a completely uncommon occurrence), genetic females will look identical to normal boys.
OK...have at it
I don’t see it mentioned:
How did they agitate the cows ?
OK...have at it
I don’t see it mentioned:
How did they agitate the cows ?
By double-posting? :-)
Exactly, but why do you think I added the question can you say balony to the title?
Hmmm....I’m a dad of three sons. Do we know each other???
LOL
Wait a second. A feisty cow? Someone out there was able to determine the difference between a feisty cow and their supposed counterpart, the demure cow, and then looked at the sex of offspring? I wish I could have been on the committee looking over THAT research proposal. In fact, I think I can write the monograph title for the next issue of “Nature” magazine:
“Cows gone wild: the impact of feisty bovine behavior on the gender of calf offspring.”
I really want to see the statistical analysis determining the amount of feisty and demure cows. Whoever said that reality has outstripped fiction for the unusual and bizarre sure had it right.
Well....
However I have my own more relevant anecdote. My daughter, the UTex Law grad, who graduated in the normal three years (of class, she took one year off as an AmeriCorps member) of law school, after being told towards the end of her first year, that she'd never pass the bar but passed it on the first try. I have 3 granddaughters. Two of them identical twins. Both pretty feisty for 7 month olds, like their big sister and their mother. Oh, and their grandma Gata is pretty feisty too. PhD, college department chair. They also have an Aunt B, but no blood uncles on their mother's side.
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