Posted on 12/10/2006 2:44:11 PM PST by Alter Kaker
A surprisingly recent instance of human evolution has been detected among the peoples of East Africa. It is the ability to digest milk in adulthood, conferred by genetic changes that occurred as recently as 3,000 years ago, a team of geneticists has found.
The finding is a striking example of a cultural practice — the raising of dairy cattle — feeding back into the human genome. It also seems to be one of the first instances of convergent human evolution to be documented at the genetic level. Convergent evolution refers to two or more populations acquiring the same trait independently.
Throughout most of human history, the ability to digest lactose, the principal sugar of milk, has been switched off after weaning because there is no further need for the lactase enzyme that breaks the sugar apart. But when cattle were first domesticated 9,000 years ago and people later started to consume their milk as well as their meat, natural selection would have favored anyone with a mutation that kept the lactase gene switched on.
Such a mutation is known to have arisen among an early cattle-raising people, the Funnel Beaker culture, which flourished some 5,000 to 6,000 years ago in north-central Europe. People with a persistently active lactase gene have no problem digesting milk and are said to be lactose tolerant.
(Excerpt) Read more at nytimes.com ...
Why, the lactase must be active in every milksot and in every sucker.
Wiped out by a tragic lab accident if I'm not mistaken.
3000 years ago? What has evolution done for us lately?
Lactose tolerance falls a little short of deriving a new species, but those Darwinists will take what they can get.
I, for one, can see how human development of tolerance for lactose demonstrates a process by which humans could have easily developed from single cell organisms. How could I have ever had any doubts.
It has provided a funding source for the creationists of this world. Without evolution to rail against, Kent Hovind wouldn't have any money to embezzle.
Now, at last, I know what "The lacteal fluid extracted from the female of the bovine species is highly prolific to the Nth degree", was referencing...
I drank lots of milk as a kid without any problem. In recent years, it's a risky endeavor.
Does this mean I'm devolving??!
Darwinists define evolution as any change whatsover. Whether helpful or harmful, whether "progress" or "regress" (meaningless terms for them, of course).
Very low threshold for this fairy tale of a theory.
Or, you might have the gene(s) that turn off at adulthood.
Or, you might well have a totally different gene that's doing something else while it incidentally creates proteins that react against your regular lactose tolerance gene(s).
There are so many possibilities and so little time.
Best bet is to get aholt of some "lactase" pills, or drink milk without lactose.
Not all differences in what appear to be genetic processes are a evolutionary in nature ~ some of them aren't even changes in genes.
Hey, It's a crevo thread. Someone has to throw the first grenade.
All I can say is 'MOOOOOOOOOOOO'.
Let's say it's a recessive, and the other one is dominant.
You could have a population of people able to drink milk no matter what, but if the mother were carrying one of each, and had at least two kids, and one kid inherited the dominant gene, and the other kid inherited the recessive gene (the father having had neither gene), one kid could drink milk and other couldn't.
Right in the same family.
So the mad scientist comes along and discovers this family has three lactose handling genes. One dominant ~ to drink. One recessive - to drink. One "old fashioned", and to drink as a child then shut down.
Which, by the way, makes sense for a friend of mine who has several children. Some of them grew up drinking milk into adulthood. Others did so only as children. He could never drink milk, nor could his wife.
The only answer we could come up with was that he and his wife both had at least one recessive for drinking milk but everything we could find suggested the milk drinking gene was dominant.
From this one case I'm going to hazard a guess that the new gene found in Africa is a recessive.
Looks like the two different genetic strains can still cross-breed too! No species difference has yet appeared.
I think the Times may have understated the degree of the mutation.
Different gene.
More worrisome is celiac syndrome ~ there you have a gene that triggers an autoimmune response to a protein in wheat, barley and rye called gluten.
This one seems to have appeared in populations isolated in the trackless wasteland of the Great White North.
Here's your diet if you are dealing with any of these things ~ reindeer, seal and pine needles ~ maybe a chunk of lichen in a hot tea every now and then.
Love dem seal!
LOL
I grew up drinking unpasteurized milk. There is quite a bit of difference in milk just in this last generation. Antibiotic "contamination", for one example. Another would be the breed of milk cow. Dairy farms are much rarer now. When you see one, you'll likely see "Holsteins". {colored like a Dalmatian} Not long ago, you would see Jerseys, Guernseys, Milking Shorthorns, and maybe others. The difference in the milk was very noticeable, even though the lactose couldn't be that much different.
I'm fascinated by some old recorded accounts from the Ozarks of an illness called "milk sick". They believed it was caused by the cow eating some type of plant and contaminating the milk. These old doctors could diagnose this condition from the odor when entering the home.
Oh, ouch. Hahaha...
Wake me up when I develop X-ray vision
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