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Gassy clue to violent star's past rages
in Brief
OLGA FILATOVA, FAR EAST RUSSIA ORCA PROJECT (FEROP, WDC)
HE WAS just the tip of the iceberg. Several rare white killer whales, or orcas, have been spotted in the western North Pacific since one nicknamed Iceberg was encountered six years ago. Researchers have discovered no fewer than five – and perhaps as many as eight – white orcas there. They are almost unheard of elsewhere in the world’s oceans, but their abundance in this region could be worrying evidence of inbreeding (Aquatic Mammals, doi.org/bqfn). “What we are seeing is strange. It’s a very high rate of occurrence,” says Erich Hoyt at Whale and Dolphin Conservation in Bridport, UK, who co-directs the Far East Russia Orca Project. It’s not clear why so many orcas there are white. They may be albinos, a condition that is often more common when populations are small and inbred. But the killer whales here are estimated to have large populations. Instead, the orcas’ unique cultural background may be behind their isolation, as they live in groups with a distinct cultural identity tied to their hunting style. “Often these populations are reproductively isolated from neighbouring populations,” says Andrew Foote at the University of Bern, Switzerland, This could lead to the populations being relatively inbred, he says.
Hair print can identify people when DNA analysis fails NEVER before has splitting hairs been so useful. Analysing the proteins in hair could provide a way to identify people when DNA sequencing fails. DNA molecules break down quickly when exposed to water, light or heat, so sometimes analysis of DNA found at a crime scene won’t work. Glendon Parker at the Lawrence Livermore National Laboratory in California and his team say hair can help in some circumstances. Hairs are made of proteins that are pieced together according to
the instructions in the genetic material of our DNA. When mutations occur in genes, it can lead to slight changes in the sequence of amino acid molecules that make up hair proteins. To use such changes to identify people, the team broke down a hair’s proteins and separated out the chunks to analyse their sequences. Comparing these results to a database of hair proteins can identify places where unexpected amino acids have been inserted. Using this approach, the team
was able to identify dozens of sequence changes in the hair of 76 living people, and hair from people who died around 1750 to 1850. They say some of the changes they found may occur in only one in 12,500 people, making them powerful markers for linking someone to the hairs left at the scene of a crime (PLoS One, doi.org/bqfq). The technique could be invaluable. “Protein is more abundant and more robust than DNA,” says Andrew Wilson at the University of Bradford, UK. Nathan Smith/UA and NASA
Iceberg the white orca is not alone
For new stories every day, visit newscientist.com/news
Squeaky love song makes fish heard SAY what? Coral reefs are notoriously noisy. So if you’re struggling to be heard, you might need to try something different. Damselfish are renowned marine chatterboxes, and several species are known to make noises. But until now, we only knew about two types of call: single pulse sounds or “pops” made when damselfish snap their teeth together, and “chirps” formed of multiple pulses joined up. Now it appears that the Ambon damselfish (Pomacentrus amboinensis) has developed a third call to help it shout above the racket. Likened to a windscreen wiper on dry glass, this sound was recorded at a reef in Taiwan (Journal of Zoology, doi. org/bqft). “It’s almost like it’s learned a new trick,” says Steve Simpson, a marine biologist at the University of Exeter, UK. He suggests that after a few fish learn to do it, the behaviour may spread socially. This new call, used during courtship and chasing rivals, is thought to help damselfish identify others of their own species in the reef environment, though it’s not yet clear exactly how they make it.
Gassy clue to violent star’s past rages IN 1843, a star called Eta Carinae erupted like a supernova yet managed to survive. A trail of gas filaments now suggests it may have had two prior outbursts hundreds of years earlier. Located 7500 light years away, Eta Carinae is actually two stars spinning tightly around each another. The smaller star is between 30 and 50 times the sun’s mass, the other between 100 and 150 times our star’s mass. This behemoth star is literally tearing itself apart, blasting photons outwards with so much
pressure that they carry away the star’s outer layers. Now that shed skin is helping to reconstruct the stars’ violent past. Using photos from the Hubble Space Telescope taken two years apart, Megan Kiminki at the University of Arizona in Tucson and her colleagues traced more than 800 gas blobs from Eta Carinae back through time. Their speeds and positions suggest that Eta Carinae had a major eruption around 1250 and a slightly less dramatic one in about 1550 (arxiv.org/abs/1609.00362).
17 September 2016 | NewScientist | 17
OLGA FILATOVA, FAR EAST RUSSIA ORCA PROJECT (FEROP, WDC)
HE WAS just the tip of the iceberg. Several rare white killer whales, or orcas, have been spotted in the western North Pacific since one nicknamed Iceberg was encountered six years ago. Researchers have discovered no fewer than five – and perhaps as many as eight – white orcas there. They are almost unheard of elsewhere in the world’s oceans, but their abundance in this region could be worrying evidence of inbreeding (Aquatic Mammals, doi.org/bqfn). “What we are seeing is strange. It’s a very high rate of occurrence,” says Erich Hoyt at Whale and Dolphin Conservation in Bridport, UK, who co-directs the Far East Russia Orca Project. It’s not clear why so many orcas there are white. They may be albinos, a condition that is often more common when populations are small and inbred. But the killer whales here are estimated to have large populations. Instead, the orcas’ unique cultural background may be behind their isolation, as they live in groups with a distinct cultural identity tied to their hunting style. “Often these populations are reproductively isolated from neighbouring populations,” says Andrew Foote at the University of Bern, Switzerland, This could lead to the populations being relatively inbred, he says.
Hair print can identify people when DNA analysis fails NEVER before has splitting hairs been so useful. Analysing the proteins in hair could provide a way to identify people when DNA sequencing fails. DNA molecules break down quickly when exposed to water, light or heat, so sometimes analysis of DNA found at a crime scene won’t work. Glendon Parker at the Lawrence Livermore National Laboratory in California and his team say hair can help in some circumstances. Hairs are made of proteins that are pieced together according to
the instructions in the genetic material of our DNA. When mutations occur in genes, it can lead to slight changes in the sequence of amino acid molecules that make up hair proteins. To use such changes to identify people, the team broke down a hair’s proteins and separated out the chunks to analyse their sequences. Comparing these results to a database of hair proteins can identify places where unexpected amino acids have been inserted. Using this approach, the team
was able to identify dozens of sequence changes in the hair of 76 living people, and hair from people who died around 1750 to 1850. They say some of the changes they found may occur in only one in 12,500 people, making them powerful markers for linking someone to the hairs left at the scene of a crime (PLoS One, doi.org/bqfq). The technique could be invaluable. “Protein is more abundant and more robust than DNA,” says Andrew Wilson at the University of Bradford, UK. Nathan Smith/UA and NASA
Iceberg the white orca is not alone
For new stories every day, visit newscientist.com/news
Squeaky love song makes fish heard SAY what? Coral reefs are notoriously noisy. So if you’re struggling to be heard, you might need to try something different. Damselfish are renowned marine chatterboxes, and several species are known to make noises. But until now, we only knew about two types of call: single pulse sounds or “pops” made when damselfish snap their teeth together, and “chirps” formed of multiple pulses joined up. Now it appears that the Ambon damselfish (Pomacentrus amboinensis) has developed a third call to help it shout above the racket. Likened to a windscreen wiper on dry glass, this sound was recorded at a reef in Taiwan (Journal of Zoology, doi. org/bqft). “It’s almost like it’s learned a new trick,” says Steve Simpson, a marine biologist at the University of Exeter, UK. He suggests that after a few fish learn to do it, the behaviour may spread socially. This new call, used during courtship and chasing rivals, is thought to help damselfish identify others of their own species in the reef environment, though it’s not yet clear exactly how they make it.
Gassy clue to violent star’s past rages IN 1843, a star called Eta Carinae erupted like a supernova yet managed to survive. A trail of gas filaments now suggests it may have had two prior outbursts hundreds of years earlier. Located 7500 light years away, Eta Carinae is actually two stars spinning tightly around each another. The smaller star is between 30 and 50 times the sun’s mass, the other between 100 and 150 times our star’s mass. This behemoth star is literally tearing itself apart, blasting photons outwards with so much
pressure that they carry away the star’s outer layers. Now that shed skin is helping to reconstruct the stars’ violent past. Using photos from the Hubble Space Telescope taken two years apart, Megan Kiminki at the University of Arizona in Tucson and her colleagues traced more than 800 gas blobs from Eta Carinae back through time. Their speeds and positions suggest that Eta Carinae had a major eruption around 1250 and a slightly less dramatic one in about 1550 (arxiv.org/abs/1609.00362).
17 September 2016 | NewScientist | 17