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Cassava packs a protein punch with bean genes
THIS WEEK
Race a Neanderthal and you will win IF YOU think you’re no good at running, bear this in mind: you could still outrun a Neanderthal. In fact, their inferior running ability may have been why they went extinct and our ancestors did not. Appropriately enough, it all came down to their Achilles tendon. There have long been claims that Neanderthals were weaker runners than modern humans, says David Raichlen of the University of Arizona in Tucson, but until now, there was no convincing evidence. In runners, the tendon acts as an energy store, stretching like a spring as the foot lands then bouncing back to help lift it again. Raichlen reasoned that the more energy is stored within the tendon, the more efficient the runner. He began by studying eight endurance runners on treadmills to find out how much energy they used at given speeds. By looking at MRI scans of their ankles, he found that the distance between a point on the heel bone just below the ankle bone, and the back of the heel bone where the Achilles tendon attaches, was proportional
Cassava packs a protein punch with bean genes A DEADLY poison could save the lives of millions of African children, thanks to the discovery that cassava can be duped into turning about half of the cyanide it makes into extra protein. Although cassava is a major source of carbohydrates for 700 million people, mostly in Africa, it normally contains only small amounts of protein. Claude Fauquet of the 12 | NewScientist | 5 February 2011
joSon/getty
Michael Marshall
bones were consistently longer than ours. Neanderthals, he concludes, would have lost a race against Homo sapiens (Journal of Human Evolution, DOI: 10.1016/j.jhevol.2010.11.002). The evidence is convincing, says palaeoanthropologist Will Harcourt-Smith, at the City University of New York. Raichlen thinks that, unlike our species, Neanderthals probably did not need to be good long-distance runners. H. sapiens lived on hot, dry African grasslands, where they hunted by pursuing large animals over long distances until they
collapsed from heat exhaustion. In the cooler regions occupied by Neanderthals, heat exhaustion would not be a problem, so running long distances would not have helped them hunt. Instead, they took advantage of their to the runner’s efficiency. The landscape and ambushed prey. shorter this distance, the greater Other palaeontologists is the force applied to stretch the push the analysis further. “The tendon – and the more energy study hits at the crux of why is stored in it. This means that Neanderthals went extinct,” says people with shorter distances are Clive Finlayson, director of the more efficient runners, using less Gibraltar Museum. energy to run for longer. John Stewart of Bournemouth Raichlen then turned to University, UK, points out that Neanderthal skeletons, and found H. sapiens remains tend to be that our distant cousins’ heel associated with animals from open habitats, while Neanderthals are found with animals from closed habitats. He and Finlayson believe that when the forests of northern Europe were wiped out by the most recent ice age, Neanderthals were squeezed out of existence as well. Archaeological evidence shows that as ice advanced from 50,000 years ago, and northern Europe’s dense forests became tundra, Neanderthals were pushed into small, isolated forest refuges in southern Europe. H. sapiens were able to adapt to hunting on the expanding European tundra. Neanderthals, says Finlayson, found themselves out of step with the environment while modern humans were perfectly suited to it. “We were in the right place at –Only an Achilles heel for Neanderthals– the right time,” he says. n
Danforth Plant Science Center in St Louis, Missouri, and his team bumped up the protein content to 12.5 per cent by adding bean and maize genes to make a protein called zeolin. They were surprised to find that the plant used its natural supply of cyanide to provide the building blocks of the new protein. “Cyanide is a source of nitrogen within the plant,” explains Fauquet. While non-modified cassava supplies just one-fifth of daily protein requirements, the extra protein is enough to supply the needs of infants on a typical cassava-based
diet (PLoS One, DOI: 10.1371/journal. pone.0016256). Fauquet says his root could save 1 in 4 African children from a potentially fatal condition called protein-energy malnutrition. However, it will be some years before it is rolled out. Although identical to the one eaten by a billion people worldwide, the added bean protein resembles one that causes rare allergic reactions. So the team
“Modified cassava could save 1 in 4 African children from dying of proteinenergy malnutrition”
has developed another version with extra protein from sweet potatoes that won’t cause allergies. “We hope to launch it in Africa in four to six years,” says Fauquet. He adds that the project, which is funded by the Bill and Melinda Gates Foundation, is purely humanitarian so the cassava would be offered free to poor farmers. Other modified staples include the “protato” developed in India, and aubergines, recently denied approval in India because of objections from groups opposed to genetically modified crops. Andy Coghlan n
Race a Neanderthal and you will win IF YOU think you’re no good at running, bear this in mind: you could still outrun a Neanderthal. In fact, their inferior running ability may have been why they went extinct and our ancestors did not. Appropriately enough, it all came down to their Achilles tendon. There have long been claims that Neanderthals were weaker runners than modern humans, says David Raichlen of the University of Arizona in Tucson, but until now, there was no convincing evidence. In runners, the tendon acts as an energy store, stretching like a spring as the foot lands then bouncing back to help lift it again. Raichlen reasoned that the more energy is stored within the tendon, the more efficient the runner. He began by studying eight endurance runners on treadmills to find out how much energy they used at given speeds. By looking at MRI scans of their ankles, he found that the distance between a point on the heel bone just below the ankle bone, and the back of the heel bone where the Achilles tendon attaches, was proportional
Cassava packs a protein punch with bean genes A DEADLY poison could save the lives of millions of African children, thanks to the discovery that cassava can be duped into turning about half of the cyanide it makes into extra protein. Although cassava is a major source of carbohydrates for 700 million people, mostly in Africa, it normally contains only small amounts of protein. Claude Fauquet of the 12 | NewScientist | 5 February 2011
joSon/getty
Michael Marshall
bones were consistently longer than ours. Neanderthals, he concludes, would have lost a race against Homo sapiens (Journal of Human Evolution, DOI: 10.1016/j.jhevol.2010.11.002). The evidence is convincing, says palaeoanthropologist Will Harcourt-Smith, at the City University of New York. Raichlen thinks that, unlike our species, Neanderthals probably did not need to be good long-distance runners. H. sapiens lived on hot, dry African grasslands, where they hunted by pursuing large animals over long distances until they
collapsed from heat exhaustion. In the cooler regions occupied by Neanderthals, heat exhaustion would not be a problem, so running long distances would not have helped them hunt. Instead, they took advantage of their to the runner’s efficiency. The landscape and ambushed prey. shorter this distance, the greater Other palaeontologists is the force applied to stretch the push the analysis further. “The tendon – and the more energy study hits at the crux of why is stored in it. This means that Neanderthals went extinct,” says people with shorter distances are Clive Finlayson, director of the more efficient runners, using less Gibraltar Museum. energy to run for longer. John Stewart of Bournemouth Raichlen then turned to University, UK, points out that Neanderthal skeletons, and found H. sapiens remains tend to be that our distant cousins’ heel associated with animals from open habitats, while Neanderthals are found with animals from closed habitats. He and Finlayson believe that when the forests of northern Europe were wiped out by the most recent ice age, Neanderthals were squeezed out of existence as well. Archaeological evidence shows that as ice advanced from 50,000 years ago, and northern Europe’s dense forests became tundra, Neanderthals were pushed into small, isolated forest refuges in southern Europe. H. sapiens were able to adapt to hunting on the expanding European tundra. Neanderthals, says Finlayson, found themselves out of step with the environment while modern humans were perfectly suited to it. “We were in the right place at –Only an Achilles heel for Neanderthals– the right time,” he says. n
Danforth Plant Science Center in St Louis, Missouri, and his team bumped up the protein content to 12.5 per cent by adding bean and maize genes to make a protein called zeolin. They were surprised to find that the plant used its natural supply of cyanide to provide the building blocks of the new protein. “Cyanide is a source of nitrogen within the plant,” explains Fauquet. While non-modified cassava supplies just one-fifth of daily protein requirements, the extra protein is enough to supply the needs of infants on a typical cassava-based
diet (PLoS One, DOI: 10.1371/journal. pone.0016256). Fauquet says his root could save 1 in 4 African children from a potentially fatal condition called protein-energy malnutrition. However, it will be some years before it is rolled out. Although identical to the one eaten by a billion people worldwide, the added bean protein resembles one that causes rare allergic reactions. So the team
“Modified cassava could save 1 in 4 African children from dying of proteinenergy malnutrition”
has developed another version with extra protein from sweet potatoes that won’t cause allergies. “We hope to launch it in Africa in four to six years,” says Fauquet. He adds that the project, which is funded by the Bill and Melinda Gates Foundation, is purely humanitarian so the cassava would be offered free to poor farmers. Other modified staples include the “protato” developed in India, and aubergines, recently denied approval in India because of objections from groups opposed to genetically modified crops. Andy Coghlan n