The Lactose Intolerance Clearinghouse Has Moved.

My old website can be found at www.stevecarper.com/li I am no longer updating the site, so there will be dead links. The static information provided by me is still sound.

For quick offline reference, you can purchase Planet Lactose: The Best of the Blog as an ebook on Smashwords.com or Amazon.com or BarnesandNoble.com or a whole lot of other places that Smashwords is suppose to distribute the book to. Almost 100,000 words on LI, allergies, milk products, milk-free products, and the genetics of intolerance, along with large helpings of the weirdness that is the Net.

I suffer the universal malady of spam and adbots, so I moderate comments here. That may mean you'll see a long lag before I remember to check the site and approve them. Despite the gap, you'll always get your say. I read every single one, and every legitimate one gets posted.


Friday, December 12, 2008

The Science of the Human Past

"The Science of the Human Past." Doesn't that sound cool? It was a symposium recently held at Harvard.

At it Mark Thomas, of University College, London, "presented evidence about one of the strongest forces that has driven human evolution in Europe over the past 20,000 years: milk." according to an article by Alvin Powell of the Harvard News Office. Here's his summary of what Thomas had to say.

Thomas' research showed that a gene variant for "lactase persistence" (LP) that allows humans to digest milk into adulthood — uncommon in most adult animals and in many human societies — swept across Europe sometime in the last 20,000 years.

To spread so rapidly, Thomas said, the gene must have conveyed an extraordinary survival advantage to those possessing it. Though science has not yet identified the specific advantages at play in early Europe, there are several potential candidates. Among them is that milk provides a ready source of calories, protein, calcium, and fat, particularly during the winter or during crop boom-and-bust cycles. It also provides an uncontaminated source of fluids, perhaps lessening illness and parasitic infections; and obtaining it may be a more economical use of lands than farming.

"In Europeans, this is probably the most strongly selected part of the genome in the last 20,000 years," Thomas said.

Thomas found that the gene variant coincided well with the rise of animal domestication, indicating that humans became dairy farmers almost as soon as they began to keep animals.

To track the gene's spread across Europe, Thomas designed a computer model that took into account both archaeological and genetic data. He then ran multiple simulations, randomly changing other variables and looking for patterns that matched what is known today.

The closest matches pegged the rise of milk-drinking Europeans to about 7,400 years ago in central Europe. The spread matched the known rapid spread of Europe’s first farmers, the Linearbandkeramik culture.

"The spread of the LP variation was shaped by selection and by an underlying demographic process, the spread of farming," Thomas said.

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