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Clue to why humans miscarry more than other species
NASA-GSFC/NOAA/GOES
IN BRIEF Ancient script ‘was a real language’
Whirling destruction saps forests’ carbon uptake DESTRUCTION wreaked by hurricanes over the past 150 years has severely affected the ability of US forests to store carbon, say ecologists. The finding suggests that an increase in hurricanes and tropical storms induced by global warming could turn forests into overall emitters of carbon dioxide, fuelling further climate change. Trees absorb CO2 from the atmosphere as they grow, then release it again when they die and decay. Ecologist Jeffrey Chambers of Tulane University in New Orleans, Louisiana, and his colleagues used data on hurricanes and the damage they have caused to estimate the total loss
of biomass in US forests for every year from 1851 to 2000. They calculated that storm damage released an average of 25 megatonnes of CO2 into the atmosphere each year. More detailed measurements for the 1980s suggest that because of this damage, US forests absorbed up to 18 per cent less CO2 than they otherwise would have – even though the decade experienced below-average hurricane damage (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0808914106). At present, worldwide forest growth offsets about 25 per cent of CO2 emissions from fossil fuels, says Chambers. But if, as many climate scientists predict, hurricanes become more common or more severe, the added forest damage that will occur in the US and elsewhere could reduce that offset substantially.
We may owe it all to asbestos EARTHQUAKES and asbestos may seem an unlikely alliance to help life evolve on early Earth, yet they could have done just that. Sea-floor fissures lined with an asbestos mineral called chrysotile are places where life could have gained a foothold 3.5 billion years ago. To mimic that environment, Naoto Yoshida and Nori Fujiura of the University of Miyazaki in Japan formed a bacterial biofilm 14 | NewScientist | 2 May 2009
on a layer of gum. They added chrysotile minerals, bacterial DNA molecules called plasmids that had genes for antibiotic resistance, and silica beads representing inert rock. They then shook the mix for 60 seconds to mimic the lowenergy tremors that would have occurred early in Earth’s history. Afterwards, when antibiotics were added to kill the bacteria, they found that about 1 in 10,000
had picked up the resistance genes (Astrobiology, DOI: 10.1089/ ast.2007.0185). Such gene transfer “would be sufficient to increase genetic variation and promote evolution”, says Yoshida. “It makes sense,” says David Cohen, at the University of New South Wales in Sydney, Australia. “The little mineral needles are puncturing the cells and allowing the plasmids in. It’s the same mechanism that punctures lung cells in asbestosis.”
A DISPUTE has erupted over the significance of symbols found on artefacts from a civilisation that flourished in the Indus valley of south Asia over 4000 years ago. From a mathematical analysis of the so-called “Indus script”, Rajesh Rao and his team at the University of Washington, Seattle, conclude that they are a kind of writing, representing a real language (Science, DOI: 10.1126/ science.1170391). This is hotly disputed by historians, who insist that they are merely a series of religious or political images. Rao and his team studied the script’s so-called “conditional entropy” – a measure of whether the words, letters and characters are ordered or random. The Indus script turned out to be about as ordered as languages like Sanskrit. It was more ordered than DNA and protein sequences, but more random than the Fortran computer language.
Chromosome clues to miscarriage WHY do women have more miscarriages than females of other species? Perhaps because it is normal for human embryos to contain cells with the wrong number of chromosomes, which can cause them to self-destruct. As women age, their eggs are more likely to have the wrong number of chromosomes, which can lead to miscarriages. But when Joris Vermeesch from the Centre for Human Genetics in Leuven, Belgium, and colleagues examined 23 embryos from nine young, fertile couples who were undergoing IVF for screening purposes, they found that 21 had chromosomal abnormalities, suggesting these are in fact the norm (Nature Medicine, DOI: 10.1038/nm.1924).
IN BRIEF Ancient script ‘was a real language’
Whirling destruction saps forests’ carbon uptake DESTRUCTION wreaked by hurricanes over the past 150 years has severely affected the ability of US forests to store carbon, say ecologists. The finding suggests that an increase in hurricanes and tropical storms induced by global warming could turn forests into overall emitters of carbon dioxide, fuelling further climate change. Trees absorb CO2 from the atmosphere as they grow, then release it again when they die and decay. Ecologist Jeffrey Chambers of Tulane University in New Orleans, Louisiana, and his colleagues used data on hurricanes and the damage they have caused to estimate the total loss
of biomass in US forests for every year from 1851 to 2000. They calculated that storm damage released an average of 25 megatonnes of CO2 into the atmosphere each year. More detailed measurements for the 1980s suggest that because of this damage, US forests absorbed up to 18 per cent less CO2 than they otherwise would have – even though the decade experienced below-average hurricane damage (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0808914106). At present, worldwide forest growth offsets about 25 per cent of CO2 emissions from fossil fuels, says Chambers. But if, as many climate scientists predict, hurricanes become more common or more severe, the added forest damage that will occur in the US and elsewhere could reduce that offset substantially.
We may owe it all to asbestos EARTHQUAKES and asbestos may seem an unlikely alliance to help life evolve on early Earth, yet they could have done just that. Sea-floor fissures lined with an asbestos mineral called chrysotile are places where life could have gained a foothold 3.5 billion years ago. To mimic that environment, Naoto Yoshida and Nori Fujiura of the University of Miyazaki in Japan formed a bacterial biofilm 14 | NewScientist | 2 May 2009
on a layer of gum. They added chrysotile minerals, bacterial DNA molecules called plasmids that had genes for antibiotic resistance, and silica beads representing inert rock. They then shook the mix for 60 seconds to mimic the lowenergy tremors that would have occurred early in Earth’s history. Afterwards, when antibiotics were added to kill the bacteria, they found that about 1 in 10,000
had picked up the resistance genes (Astrobiology, DOI: 10.1089/ ast.2007.0185). Such gene transfer “would be sufficient to increase genetic variation and promote evolution”, says Yoshida. “It makes sense,” says David Cohen, at the University of New South Wales in Sydney, Australia. “The little mineral needles are puncturing the cells and allowing the plasmids in. It’s the same mechanism that punctures lung cells in asbestosis.”
A DISPUTE has erupted over the significance of symbols found on artefacts from a civilisation that flourished in the Indus valley of south Asia over 4000 years ago. From a mathematical analysis of the so-called “Indus script”, Rajesh Rao and his team at the University of Washington, Seattle, conclude that they are a kind of writing, representing a real language (Science, DOI: 10.1126/ science.1170391). This is hotly disputed by historians, who insist that they are merely a series of religious or political images. Rao and his team studied the script’s so-called “conditional entropy” – a measure of whether the words, letters and characters are ordered or random. The Indus script turned out to be about as ordered as languages like Sanskrit. It was more ordered than DNA and protein sequences, but more random than the Fortran computer language.
Chromosome clues to miscarriage WHY do women have more miscarriages than females of other species? Perhaps because it is normal for human embryos to contain cells with the wrong number of chromosomes, which can cause them to self-destruct. As women age, their eggs are more likely to have the wrong number of chromosomes, which can lead to miscarriages. But when Joris Vermeesch from the Centre for Human Genetics in Leuven, Belgium, and colleagues examined 23 embryos from nine young, fertile couples who were undergoing IVF for screening purposes, they found that 21 had chromosomal abnormalities, suggesting these are in fact the norm (Nature Medicine, DOI: 10.1038/nm.1924).