Posted on 11/20/2004 6:42:15 AM PST by Lessismore
TORONTO, CANADA--More than 5000 experts met here from 26 to 30 October for the annual meeting of the American Society of Human Genetics. Longevity, milk digestion, and cancer were among the topics.
By some estimates, less than half of all adults can easily digest milk, a trait believed to have first appeared in people who kept dairy animals. Now scientists have traced the genetic roots of milk tolerance to the Ural mountains of western Russia, well north of where pastoralism is thought to have begun. The surprising result may support a theory that nomads from the Urals were one of two major farmer groups that spread into Europe, bringing the Indo-European languages that eventually diverged into the world's largest family of modern languages.
Almost all mammalian babies produce lactase, the enzyme that digests the milk sugar lactose. But in most animals and many people, the lactase gene is gradually turned off after infancy, leaving them unable to tolerate milk as adults. Two years ago, a team led by Leena Peltonen of the University of Helsinki, Finland, and the University of California, Los Angeles, identified mutations near the lactase gene that are associated with adult lactose tolerance and likely play a role in regulating the lactase gene. Now, Peltonen's team has tried to trace the origins of lactose tolerance by looking at 1611 DNA samples from 37 populations on four continents.
The populations having the greatest DNA sequence diversity around the lactase gene mutations--suggesting that lactose tolerance first appeared in them--include the Udmurts, Mokshas, Ezras, and other groups that originally lived between the Ural mountains and the Volga River. The trait most likely developed 4800 to 6600 years ago, Peltonen says. Her team linked the lactase gene changes to an ancestral variant that these groups apparently got from intermixing with tribes migrating from the Asian steppes.
After the Ural peoples gained this earlier form of the lactase gene, the lactose tolerance mutation "probably emerged by chance," says Peltonen, and then remained because it was beneficial for milk consumption. The Ural groups then likely later spread the variant to Europe--especially northern Europe, which has the highest lactose tolerance today--and the Middle East. The findings support the somewhat controversial theory that nomadic herders known as Kurgans expanded into Europe from the southern Urals 4500 to 3500 years ago, bringing Indo-European languages with them, according to Peltonen.
"I find [the new study] very interesting," says population geneticist Luigi Luca Cavalli-Sforza of Stanford University. He notes that a competing idea for explaining the origin of the Proto-Indo-Europeans is that they were crop-growing farmers from the Anatolia region in modern Turkey (Science, 27 February, p. 1323). But the milk study reinforces Cavalli-Sforza's view that both theories are correct: Indo-Europeans migrated to Europe in two waves, first from Turkey and later from the Urals.
Other geneticists caution that trying to pin down where a gene variant originated is tricky because the people in whom it's most common today may have migrated from somewhere else, or the original population could now be extinct. But if the milk gene's origin holds up, linguists and archaeologists will have new food for thought.
Nope, heard a college kid try it on the radio. Didn't make it. Seems strange though, something about the physical characteristic of milk that prevents absorption of a large quantity is an hour's time.
And fava beans... don't forget those...
I have personally pulled off the gallon of milk in an hour trick before, & I didn't throw up. I didn't feel well for a while afterwards, but I kept it down. So did a couple other people. (ah, college fun)
But in the 80's a bunch of "Creation Science" groups started up, with the obvious intent of making a living spreading the "Gospel" of a 6 day creation. They've recently pulled back a bit and started the "Intellegen Design" message, making more money off those books, tapes and personal appearances.
The ruckus won't die down until there is no more money to be made selling this stuff. That may take awhile.
Unfortunatly, I think this is actually damaging faith itself, because it starts fights like these where the question quickly becomes "does God exist"? Some people will certianly make the decision, "no", when they might not have even thought about it before the professional Creationists came along.
No; tummy ache, bloating (from gas), and farting.
You asked.
This is good evidence that lactose tolerance was a beneficial mutation - the realization of which can give creationists severe mental bloating.
But then there's a possible out for them: Does a mutation that keeps a gene turned on longer throughout a person's life than it used to, constitute an "increase in information"? That's where the goalposts have been moved lately, and maybe creationists can find a way to say "no, it does not increase information". If they can convince themselves of that, then they can rest easy again, secure in the knowledge that civilized society is safe for yet another day.
My cat loves milk but when she drinks it, her humans do NOT like the smell of what comes out the other end.
So far, we have not tried her on lactose-free milk, although it would be an interesting experiment.
BTW, does anyone know how much lactose is in goat's milk as opposed to cow's milk? Is this just more PETA / ELF / ALF / ASPCA leftist gibberish in line with their agenda to make mankind the lesser species?
Not necessarily--although there are other controversies about milk, such as the addition of antibiotics and hormones to the cattle feed, and the question of what effect these additives have on the humans who end up consuming milk or beef derived from said cattle.
I think a MUCH better application of GMO's would be to patent a line of cows which gave chocolate milk--I leave it to the professional agrarians and animal husbandry majors to find out whether such milk would lead to increased infection of the teats or milk ducts due to tastier (to germs) residue, etc.
Cheers!
It's in the same range. Here's a chart.
http://ourworld.compuserve.com/homepages/stevecarper/zoo.htm
I presume you're not of Northern European descent, but are a bigot.
"Billions"? Hogwash.
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If you google these terms:
percent world's population lactose intolerant
you will see estimates from 50% to 80% of the world with at least some lactose intolerance.
Makes sense -- the nomads in Central Eurasia would have had to get lactose tolerant or they wouldn't ahve been able to survive at times. I guess that drink of fermented cows milk may have started the lactose tolerance?
You have exactly zero understanding of real science, then. There are exactly zero theories or laws of science that have been proven. There never will be any empirical proof of anything in science. Science deals with evidence, not proof. Is it possible that evolution could be shown to be wrong. Absolutely. The same can be said, however, about ANY idea in science. There is never proof of the correctness of anything in science.
How can you know that anything existed before you were born and became aware? Perhaps God snapped all of into existence just for your personal existence.
Kind of like the Matrix, except you are the only one with awareness, all the rest, including history is just an illusion.
How do you know that I exist? Perhaps I'm just a bot that God created in order to excersize your mind.
Evolution makes sense, and I think it's real, because the evidence is overwhelming in the fossil and DNA record. To believe it's not, is to believe that God put all that stuff in place just to mess with our minds. I don't think God works that way. Why would he bother?
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