Indeed, we are not stating improvement, merely change. On 12/13/07, PHILIP WINESTONE <[EMAIL PROTECTED]> wrote: > > There are exquisitely beautiful cave paintings in France, dating back > about 15000 years. There are even more exquisite paintings - again in caves > in France - dating back 35000 years. Does this indicate that perhaps there > were wonderfully cultured people over 35000 years ago, and that that culture > was on a downward trend? According to PD Ouspensky - a very unusual thinker > - evolution comes in cycles, not in an upwardly trending linear fashion. > > "Where is the evidence?" you say. Well, it took only about 3000 years to > almost totally bury the pyramids... And evolution - in terms of humans > improving - depends on how you measure "improving." > > Just a thought. > > P. > > > ----- Original Message ---- > From: Harry Veeder <[EMAIL PROTECTED]> > To: [email protected] > Sent: Thursday, December 13, 2007 4:10:32 PM > Subject: [Vo]:OT: Are humans evolving faster? > > > > Published: 7 hours ago, 17:16 EST, December 10, 2007 > <http://archive.physorg.com/10/12/2007> > > Are humans evolving faster? Findings suggest we are becoming more > different, > *not alike* > > Researchers discovered genetic evidence that human evolution is > speeding up – and has not halted or proceeded at a constant rate, as had > been thought – indicating that humans on different continents are becoming > > increasingly different. > > "We used a new genomic technology to show that humans are evolving > rapidly, > and that the pace of change has accelerated a lot in the last 40,000 > years, > especially since the end of the Ice Age roughly 10,000 years ago," says > research team leader Henry Harpending, a distinguished professor of > anthropology at the University of Utah. > > document.write(""); Harpending says there are provocative implications > from > the study, published online Monday, Dec. 10 in the journal *Proceedings of > > the National Academy of Sciences*: > > -- "We aren't the same as people even 1,000 or 2,000 years ago," he says, > which may explain, for example, part of the difference between Viking > invaders and their peaceful Swedish descendants. "The dogma has been these > > are cultural fluctuations, but almost any temperament trait you look at is > > under strong genetic influence." > > -- "Human races are evolving away from each other," Harpending says. > "Genes > are evolving fast in Europe, Asia and Africa, but almost all of these are > unique to their continent of origin. We are getting less alike, not > merging > into a single, mixed humanity." He says that is happening because humans > dispersed from Africa to other regions 40,000 years ago, "and there has > not > been much flow of genes between the regions since then." > > "Our study denies the widely held assumption or belief that modern humans > [those who widely adopted advanced tools and art] appeared 40,000 years > ago, > have not changed since and that we are all pretty much the same. We show > that humans are changing relatively rapidly on a scale of centuries to > millennia, and that these changes are different in different continental > groups." > > The increase in human population from millions to billions in the last > 10,000 years accelerated the rate of evolution because "we were in new > environments to which we needed to adapt," Harpending adds. "And with a > larger population, more mutations occurred." > > Study co-author Gregory M. Cochran says: "History looks more and more like > a > science fiction novel in which mutants repeatedly arose and displaced > normal > humans – sometimes quietly, by surviving starvation and disease better, > sometimes as a conquering horde. And we are those mutants." > > Harpending conducted the study with Cochran, a New Mexico physicist, > self-taught evolutionary biologist and adjunct professor of anthropology > at > the University of Utah; anthropologist John Hawks, a former Utah > postdoctoral researcher now at the University of Wisconsin, Madison; > geneticist Eric Wang of Affymetrix, Inc. in Santa Clara, Calif.; and > biochemist Robert Moyzis of the University of California, Irvine. > > No Justification for Discrimination > > The new study comes from two of the same University of Utah scientists – > Harpending and Cochran – who created a stir in 2005 when they published a > study arguing that above-average intelligence in Ashkenazi Jews – those of > > northern European heritage – resulted from natural selection in medieval > Europe, where they were pressured into jobs as financiers, traders, > managers > and tax collectors. Those who were smarter succeeded, grew wealthy and had > > bigger families to pass on their genes. Yet that intelligence also is > linked > to genetic diseases such as Tay-Sachs and Gaucher in Jews. > > That study and others dealing with genetic differences among humans – > whose > DNA is more than 99 percent identical – generated fears such research will > > undermine the principle of human equality and justify racism and > discrimination. Other critics question the quality of the science and > argue > culture plays a bigger role than genetics. > > Harpending says genetic differences among different human populations > "cannot be used to justify discrimination. Rights in the Constitution > aren't > predicated on utter equality. People have rights and should have > opportunities whatever their group." > > Analyzing SNPs of Evolutionary Acceleration > > The study looked for genetic evidence of natural selection – the evolution > > of favorable gene mutations – during the past 80,000 years by analyzing > DNA > from 270 individuals in the International HapMap Project, an effort to > identify variations in human genes that cause disease and can serve as > targets for new medicines. > > The new study looked specifically at genetic variations called "single > nucleotide polymorphisms," or SNPs (pronounced "snips") which are > single-point mutations in chromosomes that are spreading through a > significant proportion of the population. > > Imagine walking along two chromosomes – the same chromosome from two > different people. Chromosomes are made of DNA, a twisting, ladder-like > structure in which each rung is made of a "base pair" of amino acids, > either > G-C or A-T. Harpending says that about every 1,000 base pairs, there will > be > a difference between the two chromosomes. That is known as a SNP. > > Data examined in the study included 3.9 million SNPs from the 270 people > in > four populations: Han Chinese, Japanese, Africa's Yoruba tribe and > northern > Europeans, represented largely by data from Utah Mormons, says Harpending. > > Over time, chromosomes randomly break and recombine to create new versions > > or variants of the chromosome. "If a favorable mutation appears, then the > number of copies of that chromosome will increase rapidly" in the > population > because people with the mutation are more likely to survive and reproduce, > > Harpending says. > > > "And if it increases rapidly, it becomes common in the population in a > short > time," he adds. > > The researchers took advantage of that to determine if genes on > chromosomes > had evolved recently. Humans have 23 pairs of chromosomes, with each > parent > providing one copy of each of the 23. If the same chromosome from numerous > > people has a segment with an identical pattern of SNPs, that indicates > that > segment of the chromosome has not broken up and recombined recently. > > That means a gene on that segment of chromosome must have evolved recently > > and fast; if it had evolved long ago, the chromosome would have broken and > > recombined. > > Harpending and colleagues used a computer to scan the data for chromosome > segments that had identical SNP patterns and thus had not broken and > recombined, meaning they evolved recently. They also calculated how > recently > the genes evolved. > > A key finding: 7 percent of human genes are undergoing rapid, recent > evolution. > > The researchers built a case that human evolution has accelerated by > comparing genetic data with what the data should look like if human > evolution had been constant: > > -- The study found much more genetic diversity in the SNPs than would be > expected if human evolution had remained constant. > > -- If the rate at which new genes evolve in Africans was extrapolated back > > to 6 million years ago when humans and chimpanzees diverged, the genetic > difference between modern chimps and humans would be 160 times greater > than > it really is. So the evolution rate of Africans represents a recent > speedup > in evolution. > > -- If evolution had been fast and constant for a long time, there should > be > many recently evolved genes that have spread to everyone. Yet, the study > revealed many genes still becoming more frequent in the population, > indicating a recent evolutionary speedup. > > Next, the researchers examined the history of human population size on > each > continent. They found that mutation patterns seen in the genome data were > consistent with the hypothesis that evolution is faster in larger > populations. > > Evolutionary Change and Human History: Got Milk? > > "Rapid population growth has been coupled with vast changes in cultures > and > ecology, creating new opportunities for adaptation," the study says. "The > past 10,000 years have seen rapid skeletal and dental evolution in human > populations, as well as the appearance of many new genetic responses to > diet > and disease." > > The researchers note that human migrations into new Eurasian environments > created selective pressures favoring less skin pigmentation (so more > sunlight could be absorbed by skin to make vitamin D), adaptation to cold > weather and dietary changes. > > Because human population grew from several million at the end of the Ice > Age > to 6 billion now, more favored new genes have emerged and evolution has > speeded up, both globally and among continental groups of people, > Harpending > says. > > "We have to understand genetic change in order to understand history," he > adds. > > For example, in China and most of Africa, few people can digest fresh milk > > into adulthood. Yet in Sweden and Denmark, the gene that makes the > milk-digesting enzyme lactase remains active, so "almost everyone can > drink > fresh milk," explaining why dairying is more common in Europe than in the > Mediterranean and Africa, Harpending says. > > He now is studying if the mutation that allowed lactose tolerance spurred > some of history's great population expansions, including when speakers of > Indo-European languages settled all the way from northwest India and > central > Asia through Persia and across Europe 4,000 to 5,000 years ago. He > suspects > milk drinking gave lactose-tolerant Indo-European speakers more energy, > allowing them to conquer a large area. > > But Harpending believes the speedup in human evolution "is a temporary > state > of affairs because of our new environments since the dispersal of modern > humans 40,000 years ago and especially since the invention of agriculture > 12,000 years ago. That changed our diet and changed our social systems. If > > you suddenly take hunter-gatherers and give them a diet of corn, they > frequently get diabetes. We're still adapting to that. Several new genes > we > see spreading through the population are involved with helping us prosper > with high-carbohydrate diet." > > Source: University of Utah > > >
-- That which yields isn't always weak.
