Iran dating site Free adult chat rooms maine
That the genetic changes have anything to do with brain size or intelligence "is totally unproven and potentially dangerous territory to get into with such sketchy data," stressed Dr.Francis Collins, director of the National Human Genome Research Institute.Russell Gray and Quentin Atkinson, of the University of Auckland in New Zealand use the rate at which words change to gauge the age of the tree's roots - just as biologists estimate a species' age from the rate of gene mutations.The differences between words, or DNA sequences, are a measure of how closely languages, or species, are related.Years later, a ruler declares one of those copies the definitive manuscript, and a rush is on to make many copies of that version — so whatever changes from the original are in this presumed important copy become widely disseminated.
"There's a sense we as humans have kind of peaked," agreed Greg Wray, director of Duke University's Center for Evolutionary Genomics.
"The genetic evolution of humans in the very recent past might in some ways be linked to the cultural evolution," he said.
Other scientists urge great caution in interpreting the research.
If those genes don't work, babies are born with severely small brains, called microcephaly.
Using DNA samples from ethnically diverse populations, they identified a collection of variations in each gene that occurred with unusually high frequency.