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Your molar roots are leftovers from homo erectus
THIS WEEK Insight
Genome detectives change the donation game to identify about 50 of the donors (doi.org/j9c). To prevent Erlich’s method from being used successfully again, age data has been removed from the project’s website. But the genie is out of the bottle, says Jeffrey Kahn of Florida State University in Tallahassee. While someone is bound to find another way to identify genetic donors,
Your molar roots are stuck in the past
molars to reconstruct the pace of their development, much like tree rings can be used to build a picture of tree growth. They found that the roots of chimpanzee molars go through a growth spurt as the teeth erupt through the gum – probably to provide more stability for biting and chewing. The same thing happened in early hominins, but not in modern humans: by the time our molars arrive, their roots have been fully developed for at least a year. Dean and Cole found an explanation in Homo erectus, a species who lived between 1.8 million
TALK about exploring your roots. Longer lifespans mean our adult teeth erupt later than they did in our early ancestors, but the memo didn’t make it to the roots of our molars. They develop at the same pace as they did in Homo erectus. Christopher Dean and Tim Cole at University College London studied the microscopic structure of adult 8 | NewScientist | 26 January 2013
“Anonymous” genome donors can’t always hide in the crowd
Ben Hung/getty
ARE we being too free with our genetic information? As increasing amounts of genetic information is placed online, many researchers believe that guaranteeing donors’ privacy has become an impossible task. The first major genetic data collection began in 2002 with the International HapMap Project – a collaborative effort to sequence genomes from families around the world. While its consent form assured participants that their data would remain confidential, it had the foresight to mention that future attempts to match a genome with its donor might succeed. “The risk was felt to be very remote,” says Laura Lyman Rodriguez of the US National Institutes of Health’s National Human Genome Research Institute in Bethesda, Maryland. Remote but not impossible: in a paper published in Science last week, a team led by Yaniv Erlich of the Whitehead Institute in Cambridge, Massachusetts, used publicly available genetic databases to put likely surnames to the anonymous DNA data in HapMap’s successor, the 1000 Genomes project. Then, using online phonebooks and the donor age and location information provided by the project, Erlich’s team managed
says Rodriguez, the National Institutes of Health (NIH) believe it would be wrong to remove their genome data from the public domain. She says that full accessibility is “very beneficial to science”, but acknowledges that a careful balance between confidentiality and open access is required. It is especially pertinent, says Kahn, because genetic data carries information about family members as well as the donor. A relative’s genome
and 300,000 years ago. H. erectus gained its molars at exactly the same age as our molar roots have their growth spurts. Or as Dean puts it: “Our roots are stuck in the past.” In humans, he says, root growth spurts are merely a hangover from an early stage of evolution. We retain molar roots like H. erectus because the growth spurts use too little energy for natural selection to weed
“Root growth spurts in human teeth are merely a hangover from an early stage of evolution”
might reveal your own disease risk, for example, which you might want to keep secret from an employer. An individual’s relatives could not prevent that individual from donating their genome, says Rodriguez, but would-be donors should discuss the risks and benefits with their families. David Craig of the Translational Genomics Research Institute in Phoenix, Arizona, whose method of picking a person’s genome out of a mix of DNA samples also led to NIH removing some data from the public domain, praises the work of Erlich’s team. But he is not overly concerned about the implications at this point. While Erlich was able to put names to a few genomes in the database, doing the reverse – finding the genome of a certain person – is still very difficult and has little payoff. But he acknowledges that as more people donate their genetic information, the greater the risk of someone being identified. “We can’t guarantee privacy anymore,” says Erlich. He does not expect this to deter people from donating their genetic information: the fact that credit cards are frequently stolen does not stop people from using them. That is because we trust that the legal system will protect our money; similar protections could help reassure people that their DNA will be safe. “It’s not about how to protect privacy anymore, it’s how to not misuse data,” he says. Sara Reardon n
them out (PLoS One, doi.org/j8w). H. erectus had a bigger brain and smaller teeth than its ancestors. Some believe, controversially, that these features reflected big dietary changes, including eating the first cooked food, which would have been easier to chew while supplying more energy. The new study may find favour with critics of the controversial “cooked food hypothesis”. It shows that H. erectus still required an early molar root growth spurt – presumably to prepare its teeth for heavy-duty chewing. Colin Barras n
Genome detectives change the donation game to identify about 50 of the donors (doi.org/j9c). To prevent Erlich’s method from being used successfully again, age data has been removed from the project’s website. But the genie is out of the bottle, says Jeffrey Kahn of Florida State University in Tallahassee. While someone is bound to find another way to identify genetic donors,
Your molar roots are stuck in the past
molars to reconstruct the pace of their development, much like tree rings can be used to build a picture of tree growth. They found that the roots of chimpanzee molars go through a growth spurt as the teeth erupt through the gum – probably to provide more stability for biting and chewing. The same thing happened in early hominins, but not in modern humans: by the time our molars arrive, their roots have been fully developed for at least a year. Dean and Cole found an explanation in Homo erectus, a species who lived between 1.8 million
TALK about exploring your roots. Longer lifespans mean our adult teeth erupt later than they did in our early ancestors, but the memo didn’t make it to the roots of our molars. They develop at the same pace as they did in Homo erectus. Christopher Dean and Tim Cole at University College London studied the microscopic structure of adult 8 | NewScientist | 26 January 2013
“Anonymous” genome donors can’t always hide in the crowd
Ben Hung/getty
ARE we being too free with our genetic information? As increasing amounts of genetic information is placed online, many researchers believe that guaranteeing donors’ privacy has become an impossible task. The first major genetic data collection began in 2002 with the International HapMap Project – a collaborative effort to sequence genomes from families around the world. While its consent form assured participants that their data would remain confidential, it had the foresight to mention that future attempts to match a genome with its donor might succeed. “The risk was felt to be very remote,” says Laura Lyman Rodriguez of the US National Institutes of Health’s National Human Genome Research Institute in Bethesda, Maryland. Remote but not impossible: in a paper published in Science last week, a team led by Yaniv Erlich of the Whitehead Institute in Cambridge, Massachusetts, used publicly available genetic databases to put likely surnames to the anonymous DNA data in HapMap’s successor, the 1000 Genomes project. Then, using online phonebooks and the donor age and location information provided by the project, Erlich’s team managed
says Rodriguez, the National Institutes of Health (NIH) believe it would be wrong to remove their genome data from the public domain. She says that full accessibility is “very beneficial to science”, but acknowledges that a careful balance between confidentiality and open access is required. It is especially pertinent, says Kahn, because genetic data carries information about family members as well as the donor. A relative’s genome
and 300,000 years ago. H. erectus gained its molars at exactly the same age as our molar roots have their growth spurts. Or as Dean puts it: “Our roots are stuck in the past.” In humans, he says, root growth spurts are merely a hangover from an early stage of evolution. We retain molar roots like H. erectus because the growth spurts use too little energy for natural selection to weed
“Root growth spurts in human teeth are merely a hangover from an early stage of evolution”
might reveal your own disease risk, for example, which you might want to keep secret from an employer. An individual’s relatives could not prevent that individual from donating their genome, says Rodriguez, but would-be donors should discuss the risks and benefits with their families. David Craig of the Translational Genomics Research Institute in Phoenix, Arizona, whose method of picking a person’s genome out of a mix of DNA samples also led to NIH removing some data from the public domain, praises the work of Erlich’s team. But he is not overly concerned about the implications at this point. While Erlich was able to put names to a few genomes in the database, doing the reverse – finding the genome of a certain person – is still very difficult and has little payoff. But he acknowledges that as more people donate their genetic information, the greater the risk of someone being identified. “We can’t guarantee privacy anymore,” says Erlich. He does not expect this to deter people from donating their genetic information: the fact that credit cards are frequently stolen does not stop people from using them. That is because we trust that the legal system will protect our money; similar protections could help reassure people that their DNA will be safe. “It’s not about how to protect privacy anymore, it’s how to not misuse data,” he says. Sara Reardon n
them out (PLoS One, doi.org/j8w). H. erectus had a bigger brain and smaller teeth than its ancestors. Some believe, controversially, that these features reflected big dietary changes, including eating the first cooked food, which would have been easier to chew while supplying more energy. The new study may find favour with critics of the controversial “cooked food hypothesis”. It shows that H. erectus still required an early molar root growth spurt – presumably to prepare its teeth for heavy-duty chewing. Colin Barras n