Milk

[Polynomial]

And as to my credentials, you can see my website. It's not fun or exciting, but I bet it's better than yours.

http://math.berkeley.edu/~borisp/

My god man, you probably work with Wodzicki. This explains some of the posting.

What everyone seems to ignore is how "lactose intolerant" is defined. I don't know how those studies define it, but I wouldn't be surprised if it was included the phrase "... caused a fart."

[Mark Rippetoe]

Okay, fine. Statistics, math major, all that shit. But here: "I was mainly responding to Rip's misapplication of evolution. I get irrationally "nerd angry" when I see people claim that evolution accounts for certain changes that have only occurred over a few thousand years. The choice of suggesting that he has "never taken a course in evolution" was a poor choice of words; I fully grant that one does not need coursework to understand a subject, and this sentence was out of line. However, to suggest that the ability to enjoy a lifetime of drinking milk is a consequence of us domesticating cows, and to cite evolution as the culprit, is simply a mistake."

You have not addressed the point made by my source. Evolution can and does occur over short timespans. It happens frequently, and this is a very good example of it having done so. The use of milk as a food in post-natal humans is adaptive reproductively in cultures that raise cows, the gene is there from infancy anyway and the mutation just keeps it turned on, the adaptation does not require that we evolve another arm or eyeball, and it is quite well explained in this article, which I shall now give you again: http://evolution.berkeley.edu/evolib...070401_lactose

Hell, man, they're right down the hall from you. Go talk to them sometime.

[ucbmathgsi]

Did you know that the same DNA template yields both worker/drone ants and queen ants? The difference between the two lies in the proteins that the insect is fed during development. Did you know that more than one gene can code for lactase production in human beings, and the activation of these genes can depend on what you are fed during development? Apparently the author of this article did not, or at least wished that it weren't true. More precisely, the authors' logical flaw comes when they assume that they have identified THE gene that produces lactase.

My point is that redundancy in phenotype activation is a much more likely explanation for modern man's ability to drink milk, rather than random mutation. Whether or not you prefer to call this "evolution" is up to you, I guess. I agree that modern man is much more equipped to drink milk than his ancestors.

[coldfire]

Ok, so now for some real nerd rage, since I have to respond to the quoted post. Mr. jcf, I have in fact taken a course in statistics. Had you paid attention in your course in statistics, then you would have known that Bayes' theorem is relevant here. I.e., since we already know that the OP is experiencing digestional difficulties, then his likelihood of being among the victims of lactose intolerance is skewed considerably, since lactose intolerance is among the most common explanations of digestional discomfort.

I wouldn't call what I wrote an appeal to authority, although I admit I am attacking Rip's authority in matters of evolution. And wikipedia is a useful tool that I do not apologize for using. I obviously misapplied an article to "back up" my point; in retrospect, I should have left it out, and used Bayes' theorem instead. Since you will probably knee jerk if I post a link to the wiki article on Bayes', I won't post it.

And as to my credentials, you can see my website. It's not fun or exciting, but I bet it's better than yours.

http://math.berkeley.edu/~borisp/

I won't reply for jcf, but do you have any reference that lactose intolerance is among the most common explanations of digestional discomfort? Did you really use Bayes' theorem to calculate the probability the OP is lactose interant?

P.S. You can stop the credentials crap, you are not the only Ph.D student here. Just say what you know and discuss (with a better attitude, please).

[Mark Rippetoe]

If some groups have the mutations and others don't, the phenotypic expression of these mutations is obviously dependent on ... what? They got there somehow, they get selectively turned on somehow, and their differential phenotypic expression is dependent on culture. You seem to think that there is only one mechanism by which evolution occurs -- mutation. There are several, and mutation is one of them.

Are you familiar with the cichlid radiation in Lake Victoria? This is a perfect example of rapid, diverse evolution using all the tools at the disposal of nature, due to an opportunity created by environmental factors that did not respect the slow pace of mutation. You seem to think evolution always takes a long time, because random mutations have to accumulate into adaptive change over a long time, and that is just not the case.