- Email: [email protected]
Flatworm given power to regrow its head
Matthew Oldfield Photography
IN BRIEF Stars with rhythm make better hosts
Vendettas not war? Why our ancestors killed each other IS WAR in our blood? Perhaps not: it seems violence in primitive cultures is the result of personal squabbles, rather than organised group violence. Many anthropologists believe that warfare arose deep in humans’ evolutionary past. This is in part because chimpanzees exhibit the same kind of intergroup violence, suggesting a common origin for the trait. Yet the archaeological record of human warfare is sketchy. To find out more, Douglas Fry and Patrik Soderberg of Åbo Akademi University in Vasa, Finland, examined ethnographic accounts of 21 traditional societies of
nomadic hunter-gatherers, reasoning that these groups would most closely resemble early human societies. Accounts dating from the 17th century showed that violent deaths were rare; the vast majority were one-on-one killings not warfare (Science, doi.org/m88). Fry and Soderberg conclude that warfare may have become common only after the rise of complex societies. If so, it would have had only a minor role in our evolution. Not everyone agrees. Sedentary foragers were excluded from the study, but they would have occupied the richest habitats, so were most likely to have wars over territory, says Richard Wrangham at Harvard University. Even if warfare is uncommon, it can still exert an important evolutionary force, adds Sam Bowles at the Santa Fe Institute in New Mexico.
Tweak a gene to grow a new head IF YOU can’t keep your head when all about you are losing theirs – then why not grow a new one? Decapitated flatworms have had their genes tweaked so that they can regrow a head. Some flatworms are champions at regrowing body parts, but not all flatworm species have such a talent. Jochen Rink at the Max Planck Institute of Molecular Cell Biology 18 | NewScientist | 27 July 2013
and Genetics in Dresden, Germany, and his colleagues investigated what gives some flatworms regenerative properties. They discovered a network of genes controlling head regeneration that is essentially the same in all flatworm species, but different species express different levels of some genes. Tweaking the expression of just one gene in the network – beta-
catenin – in a flatworm species that can’t usually regenerate allowed it to regrow a head (Nature, DOI: 10.1038/nature12414). When we get a cut, there is a wound response that forms a scar, but in these animals the wound response is translated into a regenerative response, says Aziz Aboobaker at the University of Oxford. Whether we can apply this to biomedical regeneration in humans is the next big question, he says.
STELLAR couples known as binaries could be even better for life than lone stars like our sun. Young stars start out with volatile temperaments, which is bad news for nearby planets. The stars’ fast rotation rates boost their magnetic field strength, causing them to spit out harmful radiation and strong stellar winds that can strip away some planets’ life-friendly traits. Stars naturally slow their rotation as they age, reducing their activity. Now Paul Mason of the University of Texas at El Paso and colleagues say that binaries can settle down even earlier if their gravitational tango helps them synchronise rotation rates. The team applied their idea to models of six known binary systems and found that some are in synch as predicted (arxiv.org/ abs/1307.4624). The effect should allow more habitable planets to prosper around binaries.
Let the black hole feasting begin TALK about a supersize meal. The supermassive black hole at the centre of our galaxy has begun to chow down on a passing gas cloud three times Earth’s mass. In 2011, it became clear that the cloud, G2, was falling towards the black hole, Sagittarius A*, which has the mass of four million suns. Now the European Southern Observatory says the head of the cloud has slammed into matter swirling around the black hole, some of which will be swallowed, while the tail is still approaching (arxiv.org/abs/1306.1374). Light from the collision should help test Einstein’s theory of general relativity, and tell us more about two huge bubbles of hot gas at the centre of the Milky Way that the black hole may have spawned.
IN BRIEF Stars with rhythm make better hosts
Vendettas not war? Why our ancestors killed each other IS WAR in our blood? Perhaps not: it seems violence in primitive cultures is the result of personal squabbles, rather than organised group violence. Many anthropologists believe that warfare arose deep in humans’ evolutionary past. This is in part because chimpanzees exhibit the same kind of intergroup violence, suggesting a common origin for the trait. Yet the archaeological record of human warfare is sketchy. To find out more, Douglas Fry and Patrik Soderberg of Åbo Akademi University in Vasa, Finland, examined ethnographic accounts of 21 traditional societies of
nomadic hunter-gatherers, reasoning that these groups would most closely resemble early human societies. Accounts dating from the 17th century showed that violent deaths were rare; the vast majority were one-on-one killings not warfare (Science, doi.org/m88). Fry and Soderberg conclude that warfare may have become common only after the rise of complex societies. If so, it would have had only a minor role in our evolution. Not everyone agrees. Sedentary foragers were excluded from the study, but they would have occupied the richest habitats, so were most likely to have wars over territory, says Richard Wrangham at Harvard University. Even if warfare is uncommon, it can still exert an important evolutionary force, adds Sam Bowles at the Santa Fe Institute in New Mexico.
Tweak a gene to grow a new head IF YOU can’t keep your head when all about you are losing theirs – then why not grow a new one? Decapitated flatworms have had their genes tweaked so that they can regrow a head. Some flatworms are champions at regrowing body parts, but not all flatworm species have such a talent. Jochen Rink at the Max Planck Institute of Molecular Cell Biology 18 | NewScientist | 27 July 2013
and Genetics in Dresden, Germany, and his colleagues investigated what gives some flatworms regenerative properties. They discovered a network of genes controlling head regeneration that is essentially the same in all flatworm species, but different species express different levels of some genes. Tweaking the expression of just one gene in the network – beta-
catenin – in a flatworm species that can’t usually regenerate allowed it to regrow a head (Nature, DOI: 10.1038/nature12414). When we get a cut, there is a wound response that forms a scar, but in these animals the wound response is translated into a regenerative response, says Aziz Aboobaker at the University of Oxford. Whether we can apply this to biomedical regeneration in humans is the next big question, he says.
STELLAR couples known as binaries could be even better for life than lone stars like our sun. Young stars start out with volatile temperaments, which is bad news for nearby planets. The stars’ fast rotation rates boost their magnetic field strength, causing them to spit out harmful radiation and strong stellar winds that can strip away some planets’ life-friendly traits. Stars naturally slow their rotation as they age, reducing their activity. Now Paul Mason of the University of Texas at El Paso and colleagues say that binaries can settle down even earlier if their gravitational tango helps them synchronise rotation rates. The team applied their idea to models of six known binary systems and found that some are in synch as predicted (arxiv.org/ abs/1307.4624). The effect should allow more habitable planets to prosper around binaries.
Let the black hole feasting begin TALK about a supersize meal. The supermassive black hole at the centre of our galaxy has begun to chow down on a passing gas cloud three times Earth’s mass. In 2011, it became clear that the cloud, G2, was falling towards the black hole, Sagittarius A*, which has the mass of four million suns. Now the European Southern Observatory says the head of the cloud has slammed into matter swirling around the black hole, some of which will be swallowed, while the tail is still approaching (arxiv.org/abs/1306.1374). Light from the collision should help test Einstein’s theory of general relativity, and tell us more about two huge bubbles of hot gas at the centre of the Milky Way that the black hole may have spawned.