Thanks, explains why sitting all day at my computer has caused a widening of the arteries...no deer to chase in here...no, wait...*DEER!*
Liz, I know you will understand:) On Mon, Jan 12, 2009 at 6:33 PM, Liz Purkrabek <[email protected]>wrote: > Nomadic hand-me-downs: what is to blame for obesity, lactose intolerance, > and ADHD? Some researchers are pointing squarely at hunter-gatherers.(data). > > Author(s):Emily Anthes. > > Source:*Discover > *<http://find.galegroup.com.ezproxy.memphis.edu/itx/publicationSearch.do?queryType=PH&inPS=true&type=getIssues&prodId=ITOF¤tPosition=0&userGroupName=tel_a_uofmem&searchTerm=Discover&index=JX&tabID=T003&contentSet=IAC-Documents>29.12 > (Dec > 2008): p12(1). (506 words) > > Document Type:Magazine/Journal > > Bookmark:Bookmark this > Document<http://find.galegroup.com.ezproxy.memphis.edu/itx/generateInfomark.do?docType=IAC&contentSet=IAC-Documents&type=retrieve&tabID=T003&PDFRange=%5B%5D&pageNumber=&docId=A191854539&searchId=R2&prodId=ITOF¤tPosition=6&userGroupName=tel_a_uofmem&qrySerId=Locale%28en%2C%2C%29%3AFQE%3D%28KE%2CNone%2C42%29%22Attention+Deficit+Hyperactivity+Disorder%22%24&inPS=true&pageIndex=0> > > Library Links: > > - > - > > *Full Text :*COPYRIGHT 2008 Discover Media LLC > > The ADHD children of the world may have their wandering ancestors to blame. > A genetic variant associated with impulsivity, novelty seeking, and > attention deficit hyperactivity disorder (ADHD) might have actually been > adaptive in nomadic populations, according to a recent study by Dan > Eisenberg at Northwestern University. Kenyan nomads with this variant, he > says, may have been better at searching for food and defending their > resources, giving them a survival advantage. But the study shows that the > nomads' settled descendants who carried this gene were more often > malnourished than those without the gene. "Just because we don't see a trait > as being currently advantageous," Eisenberg says, "does not preclude the > trait from having had a function in the past." Geneticists continue to > unravel our ancestral evolution in hopes of better understanding how > formerly advantageous genes have led to modern-day health problems. > > HIGH BLOOD PRESSURE > > High blood pressure may be caused by a gene that was key to nomadic > survival. The ability to retain salt--controlled in part by a gene called > CYP3A5--varies by latitude, according to geneticists at the University of > Chicago. The closer a population lives to the equator, the better > individuals are at retaining salt. "Since hunter-gatherers weren't assured > of getting sodium every day, they needed to be sure not to lose what they > did acquire," says Alan Weder, a hypertension specialist. But bring this > gene to a modern setting--with couch lounging and salty snacking--and it is > easy to retain more salt than is needed, which can lead to medical problems > like high blood pressure. > > [GRAPHIC OMITTED] > > LACTOSE INTOLERANCE > > Whether or not you can drink milk may depend on where your nomadic > ancestors settled down. Early humans, like other mammals, were able to > digest milk only during infancy. But when humans started raising cows and > milk became widely available, an ability to digest it brought a selective > advantage, according to genetic research by Cornell University biologist > Paul Sherman. DNA analysis of skeletons from between 5840 and 5000 B.C. > found evidence that the early wave of European farmers could not produce the > enzyme lactase, which permits the digestion of milk, while later farmers > could. In regions where dairy farming is currently not safe or economical > because of an extreme climate or cattle diseases, Sherman says, populations > still possess ancestral genes that make them lactose intolerant. > > OBESITY > > Could our growing waistlines be blamed on nomadic ancestors? Some > scientists think so. The Pima Indians of Arizona are a recently settled > group whose members today have sky-high rates of obesity and diabetes, > thanks to their genes, say Leslie Baler and her colleagues at the National > Institute of Diabetes and Digestive and Kidney Diseases. Eight years ago, > Baler identified a genetic variation in the Pimas associated with slowed > metabolism and increased glucose conservation. Researchers think that the > gene helped Pima ancestors survive food shortages. Though most of us are not > Pimas, our own hunter-gatherer forebears would also have needed to survive > food shortages and scarcity-conditions that favor the evolution of similar > fat-storing mechanisms, which are a problem in times of plenty. > > > > *Source Citation:*Anthes, Emily. "Nomadic hand-me-downs: what is to blame > for obesity, lactose intolerance, and ADHD? Some researchers are pointing > squarely at hunter-gatherers.(data)." *Discover* 29.12 (Dec 2008): 12(1). > *General OneFile*. Gale. University of Memphis. 12 Jan. 2009 > <http://find.galegroup.com.ezproxy.memphis.edu/itx/start.do?prodId=ITOF>. > > *Gale Document Number:*A191854539 > > > > > > > > > > -- gnothe se auton --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Memphis Freethought Alliance" group. 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