- Email: [email protected]
Past climate change influenced human evolution
ben curtis/ap/pa
THIS WEEK explanation is correct, the study opens up a new question: can humans evolve to adapt to climate change? “Over the long term, if the Earth keeps warming, I would not be surprised to see genetic shifts,” says anthropological geneticist Anne Stone at Arizona State University in Tempe. Predicting what a human of the future will look like is difficult, however, as there will be competing selection pressures. Take body shape. Stephen Stearns, an evolutionary biologist at Yale University, has suggested that because shorter, heavier women tend to have more children, who inherit these traits, we can expect the average woman to be shorter and heavier by 2049. But Stone –Genes to cope with desert living– predicts that because species in hot environments evolve body from 39 human populations shapes that radiate heat better, around the world, including the climate change will cause humans Yoruba, and found that the same to grow taller and slimmer. “It’s genetic sequence was found at likely we’ll find a sweet spot where higher frequencies in lower we’re able to cope with higher latitudes. Since lower latitudes are more likely to be regions of water- “If the Earth keeps warming it would not be that it had been naturally selected stress, this suggests that the surprising to see genetic (BMC Evolutionary Biology, DOI: selection pressure was climateshifts in humans” 10.1186/1471-2148-10-267). related, says Moreno. The length of the genetic However, Steve Jones, a signature suggests that the change geneticist at University College temperatures, but still carry occurred in the last 10,000 to London, points out that the enough fat to be reproductively 20,000 years, which could have evidence is only indirect, since we successful,” she says. coincided with the initial stages don’t know whether the genetic Aside from reproductive success, of the desertification of the variance in the Yoruba people the major driver of evolution is Sahara. They also analysed a actually boosts their survival. differences in mortality. The region of the gene in 971 samples Nonetheless, if Moreno’s distribution of disease is expected to change as the world heats up, for example. The ease of transport Humans are still evolving: the evidence and the global population mean to recent natural selection. While we may look like the finished that humans are more at risk of article, there is plenty of evidence n The ability to digest milk only disease than at any other time in that humans are still evolving. evolved in the last 7000 years, our evolutionary history, Jones John Hawks at the University of says Mark Thomas of University says. “If anything is likely to Wisconsin-Madison even argues that College London. evolve quickly, it’ll be the genes population explosions and rapidly n Genes for early childbirth will that give you resistance to changing lifestyles are causing be naturally selected for over time, disease,” he adds. humans to evolve faster now than according to a study by Ian Owen’s Evolution is a slow process, ever before. Evidence includes: team at Imperial College London. however, so any adaptation would n The human brain is still evolving. n It took just 3000 years for Tibetans not save us from the imminent Bruce Lahn at the University of to adapt to life at high altitudes, a problems associated with climate Chicago and colleagues identified record-breaking rate, says Rasmus change. “We’re not going to evolve two genes involved in regulating Nielsen’s team at the University of our way out of trouble,” says brain size that have been subject California, Berkeley. Jones. “The answer lies in our skulls, not our testicles.” n
Is climate shaping human evolution? Jessica Hamzelou
AS THE climate changes and the world warms, will humans evolve to handle the effects? Maybe, if the Yoruba people of west Africa’s response to living in arid conditions is anything to go by. Whether there is enough time to adapt is another matter. The Yoruba have been exposed, historically, to the dry conditions of the Sahel on the edge of the Sahara desert. To find out whether they had evolved to cope, Andres Moreno at Stanford University in California and colleagues looked at the variation of a gene known to be involved in water retention in the kidney, called FOXI1, in DNA samples from 20 Europeans, 20 east Asians and 20 Yoruba. The team found that 85 per cent of the Yoruba had an identical sequence of genetic information that was longer than it would have been if it was produced by random recombination and genetic shuffling. Instead, they suggest 12 | NewScientist | 23 October 2010
THIS WEEK explanation is correct, the study opens up a new question: can humans evolve to adapt to climate change? “Over the long term, if the Earth keeps warming, I would not be surprised to see genetic shifts,” says anthropological geneticist Anne Stone at Arizona State University in Tempe. Predicting what a human of the future will look like is difficult, however, as there will be competing selection pressures. Take body shape. Stephen Stearns, an evolutionary biologist at Yale University, has suggested that because shorter, heavier women tend to have more children, who inherit these traits, we can expect the average woman to be shorter and heavier by 2049. But Stone –Genes to cope with desert living– predicts that because species in hot environments evolve body from 39 human populations shapes that radiate heat better, around the world, including the climate change will cause humans Yoruba, and found that the same to grow taller and slimmer. “It’s genetic sequence was found at likely we’ll find a sweet spot where higher frequencies in lower we’re able to cope with higher latitudes. Since lower latitudes are more likely to be regions of water- “If the Earth keeps warming it would not be that it had been naturally selected stress, this suggests that the surprising to see genetic (BMC Evolutionary Biology, DOI: selection pressure was climateshifts in humans” 10.1186/1471-2148-10-267). related, says Moreno. The length of the genetic However, Steve Jones, a signature suggests that the change geneticist at University College temperatures, but still carry occurred in the last 10,000 to London, points out that the enough fat to be reproductively 20,000 years, which could have evidence is only indirect, since we successful,” she says. coincided with the initial stages don’t know whether the genetic Aside from reproductive success, of the desertification of the variance in the Yoruba people the major driver of evolution is Sahara. They also analysed a actually boosts their survival. differences in mortality. The region of the gene in 971 samples Nonetheless, if Moreno’s distribution of disease is expected to change as the world heats up, for example. The ease of transport Humans are still evolving: the evidence and the global population mean to recent natural selection. While we may look like the finished that humans are more at risk of article, there is plenty of evidence n The ability to digest milk only disease than at any other time in that humans are still evolving. evolved in the last 7000 years, our evolutionary history, Jones John Hawks at the University of says Mark Thomas of University says. “If anything is likely to Wisconsin-Madison even argues that College London. evolve quickly, it’ll be the genes population explosions and rapidly n Genes for early childbirth will that give you resistance to changing lifestyles are causing be naturally selected for over time, disease,” he adds. humans to evolve faster now than according to a study by Ian Owen’s Evolution is a slow process, ever before. Evidence includes: team at Imperial College London. however, so any adaptation would n The human brain is still evolving. n It took just 3000 years for Tibetans not save us from the imminent Bruce Lahn at the University of to adapt to life at high altitudes, a problems associated with climate Chicago and colleagues identified record-breaking rate, says Rasmus change. “We’re not going to evolve two genes involved in regulating Nielsen’s team at the University of our way out of trouble,” says brain size that have been subject California, Berkeley. Jones. “The answer lies in our skulls, not our testicles.” n
Is climate shaping human evolution? Jessica Hamzelou
AS THE climate changes and the world warms, will humans evolve to handle the effects? Maybe, if the Yoruba people of west Africa’s response to living in arid conditions is anything to go by. Whether there is enough time to adapt is another matter. The Yoruba have been exposed, historically, to the dry conditions of the Sahel on the edge of the Sahara desert. To find out whether they had evolved to cope, Andres Moreno at Stanford University in California and colleagues looked at the variation of a gene known to be involved in water retention in the kidney, called FOXI1, in DNA samples from 20 Europeans, 20 east Asians and 20 Yoruba. The team found that 85 per cent of the Yoruba had an identical sequence of genetic information that was longer than it would have been if it was produced by random recombination and genetic shuffling. Instead, they suggest 12 | NewScientist | 23 October 2010