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Tue 1 Apr, 2003 12:16 pm
I just read a fascinating article in Discover magazine that peaked my anthropology-bone. It was about an appalachain ancesteral line called Melungeon. There are upwards of 200,000 americans in this group of sometimes dark eyed, olive skinned tribe. Being from the South, many of these folks were ill-treated as blacks or mulatoes, segregated out of mainstream.
Well, one melungeon started a geneaology movement to try to get down to who the group was - what the ancerstry was. Many assumed native and african descent. Some thought there was some arabic or indian blood. Turns out that the break down was about 5% native american, 5% african, 85% european. The very interesting bits, to me, was that there was mitochondrial(mt) DNA (passed only through the females in a line)
"from an Indian group called the Siddha that may have originated in North Africa and given rise to europe's Roma, or Gypsies."
The reason why that is interesting is that it shows just how much the human species has mixed up all their DNA. How we can still be discriminating on the basis of race is mind-boggling.
Another interesting side note:
"Three years ago..., at the Universtiy of Arizona, geneticist Michael Hammer studied the Y chromosomes of Jewish men from Europe, Africa, and the Middle East. Their genes had more in common with one another than with most of their non-Jewish neighbors, he found. But they were indistinguishable from those of Palestinians and Syrians."
Awesome! I adore genetics and would've gone into it if not for icky chemistry.
Saw an interesting program a couple of months ago (on the Science Channel, I think; sorry I can't recall too many of the particulars). It was about a small village in England wherein the records indicated that in the 14th century they had an unusually high percentage of plague survivors - or people who had never gotten the plague to begin with. Geneticists did a study and determined there were genes in common among the villagers - 2 copies seemed to mean plague immunity, while 1 copy of the gene seemed to mean that you'd get the plague but were likely to recover from it. Even more remarkable, to my mind, was the idea that this same gene might also confer some immunity to HIV.
Never saw anything else on this study.
Jes - that is cool. I know I've read that there are people with apparent HIV immunity.
Or is that AIDS immunity.....? Maybe both? Sigh.
I want to bring this back up into the current topics.
The use of Short Tandem Repeat (STR) alleles, in the interon portions of a gene also can provide certain population information and, by virtue of its precision, give us a feel as to how the human daughter populations had migrated from the population homeland. This has opened a entire area of interest in forensic sciences (hate to get gruesome here)> It often becomes necessary to identify human remains in mass burials and to define their linneage as belonging to a certain population and STR typology is growing as a template of the distribution of the human genome. Its so fundamental to anthropology that , to me, its like the postulation of Dark Matter in cosmology.
Another area that strikes closer to home in my profession is the use of sequencing of paleo proteins in chitin or osteocalcin,which are DNA remnants. PAleontologists have always looked at assigning superorder status to animals by virtue of their bone structure. DNA and proto protein stuies are now beginning to rearrange the evolutionary family trees so that (at least in fishes and mammals) there are now less 5 extant superorders of mammals and only 3 of fish. (This is great because the paleontologists were always too smug for me)
Farmerman - you are an anthropologist then? It would be interesting to see some threads where you talk about your work at some stage........
No, I am not an anthropologist. Im a geologist who has not learned to keep his big yap shut. As such, I am sometimes drafted to go and present cases before state ed boards . In the US we are being over run by Creationist and Intelligent Design proponents who wish to have their points od view taught in high school biology and earth science.
Im actually a prospector at heart. Geology seemed a valid educational route to take if I wanted to travel around godawful countrysides in rickety leaking Land Rovers.
Chitin is a complex polysaccharide, not a protein. What's being sequenced in this saccharide, which already has a well delinated structure?
farmerman, I'd be quite happy for you to discuss geology as well. I was educated as a anthropologist, but I love rocks.
I don't know nuthin' 'bout nuthin', but touching on something that was briefly mentioned: it's very likely that an AIDS epidimic is allowed to run its course (as it is in certain parts of the world), populations will eventually replinish and emerge highly resistant to the disease. Likely HIV would still be endemic, as it is in many wild chimpanzee populations. (Imagine the consternation of all those researchers who acquired chimps to infect with HIV, only to find out that they don't develop AIDS -- to say nothing of the chimps themselves.)
As to chitin and osteocalcin, my guess would be that farmerman is referring to proteins which are embedded in and preserved in the substances. Since they originate in an extracellular matrix, bones and shells (even old ones) may contain many secreted proteins -- perhaps even some that are intact enough to sequence: paleo proteins. Would be a very big deal, indeed, to be able to establish ancient cladisitic relationships with molecular evidence. Proteins are much more telling than skeletons.
Just my guess at reading it. Trying to avoid education until my other two classes start up again on Monday, so that's as far as I go.
As to the intended topic -- hmmmmmmmmm....
yeah, he don't know nothin'.....
New Haven, you are correct, but its a polysach that contains amide groups and is layered. Maybe that is where they do the sequencing .I didnt say they sequenced chitin but proteins from chitin Remember were looking for paleo amino compounds. Bone usually goes from a flouroapetite to a flourosilicate. Therefore digestion in HF is easy. I have no idea what is done with the paleo chitin material . Or whether the layers of a chitinaceous shell are used or whether its connective material.
(see, k'? I told you I didn't...)
patio-dog, you are correct in that assertion where the proteins in chitin layers comes from. Im not sure either and your guess is as good as any. I only read this sh!t and tell you guys, I dont go out and do bone or crab shell digestions(MMMMMMMMMMMM CRAB) . Crissakes how would I earn a living? Ive already tried teaching and , unless I got a good offer from U of Texas at Austin, I would never ever do that again.
Research grants that make up so much of the "PorP" syndrome are mainly divvied up by the host institutions for overhead and depreciation. The guy whos reputation brought in the grant gets doodly. I figgered I could cut out that entire university and still teach in an adjunct capacity (If teaching is what I would like to do)
But, I digress. I will shut up now and get back to my potato chips and 7UP
mmmmmm, crab. is it too late for a bug hunt?
er, the gathering, killing, cleaning, boiling, and consuming of marine crustaceans. sorry.
yeh, ya have ta be there to understand.
ah, I'm so sure we don't have those here in the bay state (grin).
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