The next 200 years: are Modern Humans Evolving Faster?

September 2, 2009 at 4:31 pm (science) (, )

shutterstock_4160650“We are more different genetically from people living 5,000 years ago than they were different from Neanderthals.”

John Hawks -University of Wisconsin anthropologist

In a fascinating discovery that counters a common theory that human evolution has slowed to a crawl or even stopped in modern humans, a study examining data from an international genomics project describes the past 40,000 years as a time of supercharged evolutionary change, driven by exponential population growth and cultural shifts.

The findings may lead to a very broad rethinking of human evolution, especially in the view that modern culture has essentially relaxed the need for physical genetic changes in humans to improve survival.

A team led by University of Wisconsin-Madison anthropologist John Hawks estimates that positive selection just in the past 5,000 years alone -dating back to the Stone Age – has occurred at a rate roughly 100 times higher than any other period of human evolution. Many of the new genetic adjustments are occurring around changes in the human diet brought on by the advent of agriculture, and resistance to epidemic diseases that became major killers after the growth of human civilizations.

“In evolutionary terms, cultures that grow slowly are at a disadvantage, but the massive growth of human populations has led to far more genetic mutations,” says Hawks. “And every mutation that is advantageous to people has a chance of being selected and driven toward fixation. What we are catching is an exceptional time.”

While the correlation between population size and natural selection is nothing new – it was a core premise of Charles Darwin, Hawks says – the ability to bring quantifiable evidence to the table is a new and exciting outgrowth of the Human Genome Project.

(the Rest: Daily Galaxy)

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Open Source DNA

September 1, 2009 at 6:02 am (science) (, , )

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In the chilling science fiction movie Gattaca, Ethan Hawke stars as a man with “inferior genes” who assumes another’s genetic identity to escape a dead-end future. The 1997 film illustrates the very real fear swirling around today’s genome research — fear that private genetic information could be used negatively against us.

Last year, after a published paper found serious security holes in the way DNA data is made publicly available, health institutes in the United States and across the world removed all genetic data from public access.

“Unfortunately, that knee-jerk response stymied potential breakthrough genetic research,” says Dr. Eran Halperin of Tel Aviv University’s Blavatnik School of Computer Sciences and Department of Molecular Microbiology and Biotechnology. He wants to put this valuable DNA information back in circulation, and has developed the tool to do it — safely.

TAU

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Survival in a post-apocalypse blackout

August 26, 2009 at 8:13 pm (ecology, science) (, , )

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NATURAL catastrophes such as asteroid impacts, massive volcanic eruptions or large-scale wildfires would have periodically plunged our planet into abnormal darkness. How did life survive without the sun’s life-giving rays during such episodes? With a little help from organisms that can switch to another source of energy while they wait for sunlight to pierce the darkness once more.

To figure out how organisms might have endured periods of so-called “catastrophic darkness”, Charles Cockell of the Open University’s Centre for Earth, Planetary, Space and Astronomical Research in Milton Keynes, UK, and his team placed samples of both freshwater and marine microorganisms in darkness for six months – a period similar to what might be expected following a catastrophic event. The samples included phototrophs, which convert sunlight into usable energy, and mixotrophs, which can use sunlight or consume dead organic matter.

via New Scientist

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