agnieszka biskup — writer & editor

It’s hard to know when clothing originated because cloth fibers don’t last as long as, say, bones or stone tools. But researchers from the Max Planck Institute for Evolutionary Anthropology in Germany have found an ingenious way to date the origin of clothes by using lice, they report in last week’s Current Biology. The head louse and the body louse differ by where they live on their victims, which are exclusively human. Both parasites feed on the body, but the body louse only lives in clothes. The researchers believe that the differentiation between the lice “probably arose when humans adopted frequent use of clothing.” If they could find when the body louse evolved from the head louse, they could date the origin of clothes. Mark Stoneking and colleagues compared DNA from the lice and found that the body louse evolved from the head louse about 70,000 years ago, and the researchers believe that it is also when clothing — the louse’s living quarters — first became widespread.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 8/26/2003.

Researchers presented yet more evidence in last week’s Monthly Notices of the Royal Astronomical Society that the universe is eventually going to end up a dark, cold place, the stars winking out one by one. Research student Ben Panter and professor Alan Heavens of Edinburgh University’s Institute of Astronomy, along with the University of Pennsylvania’s Raul Jimenez have calculated that the rate of star formation has been in decline for about 6 billion years, from about the time our own sun was born. The team analyzed starlight from almost 40,000 galaxies to find out how many recently formed stars there were during different periods of the universe’s 14-billion-year-old existence. More stars are dying than being born, a definite population bust. Heavens stated in a press release: “Our analysis confirms that the age of star formation is drawing to a close.”

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 8/26/2003.

Divorce can be a good thing, but you need to be the dumper and not the dumpee, at least if you’re the shorebird known as the oystercatcher. Dik Heg of the University of Bern in Switzerland and his colleagues studied the fitness consequences of bird divorce and reported their observations in the July issue of Animal Behaviour. “Survival and reproduction prospects for oystercatchers are largely determined by their social status,” the researchers stated. The team found that the birds that left their partners had no change in status, but the status of birds that were deserted declined. According to Nature’s Science Update, the birds that initatiated the break up (usually females) were more likely to get a better nesting spot closer to their mudflat feeding grounds, and also bear up to 20 percent more young. The dumpees, on the other hand, often ended up at nesting spots far away from the mudflats. Having to fly the extra distance leaves chicks open to predation and makes it easier for the new partner to be unfaithful. Survival after divorce was also significantly lower for the birds that were deserted, compared to those who left their mates. It seems that even for birds, being dumped can be traumatic.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 8/26/2003.

Contrary to popular opinion, the big, dominant male isn’t the one the ladies like. For certain salmon and quail, the wimpy guys make the girls swoon, reports New Scientist. At an Animal Behavior Society meeting in Idaho last month, Jason Watters of the University of California at Davis announced that he has found that female coho salmon prefer to mate with smaller male cohos, known as jacks, rather than the larger, more aggressive males known as hooknoses. Watters said he believes that the females may prefer jacks because they’re gentler: “Hooknoses were the only ones that chased or bit females. Jacks pull up beside females and wiggle. They don’t touch them; they just advertise. Continue reading →

Do you think the ancient cobwebs hanging in your attic are old? Well, Samuel Zschokke of the University of Basel in Switzerland has you beat. Zschokke reports in the Aug. 7 Nature that he has found a strand of spider silk preserved in amber that is 130 million years old. His discovery beats the age of the previously known oldest spider thread by some 90 million years. The amber contains a single strand about 4 millimeters, or about a .16 of an inch long and is coated with sticky glue droplets (presumably to better catch prey) similar to those produced by many of today’s spider species. Zschokke writes that the strand “shows a striking resemblance to recent araneoid spider threads.” (Araneoid spiders spin sticky, intricate orb-webs.) The specimen gives “direct evidence for the antiquity” of sticky spider silk, though Zschokke cautions, “the fossil thread could have been part of a web type that no longer exists today.”

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 8/19/2003.

The famous 5,000-year-old iceman nicknamed “Otzi” died fighting, researchers from the University of Queensland in Australia told the BBC. Found in the Italian Alps in 1991, Otzi’s discovery made headlines around the world because his frozen remains were almost perfectly preserved. But the means of his death was the cause of much speculation. A flint arrowhead was found in his shoulder a few years ago, but only recently has more evidence of his final hours come to light. Molecular archeologist Tom Loy analyzed traces of blood found on Otzi’s clothes and weapons, and discovered that the blood came from several different people. There was also evidence of defensive cuts on Otzi’s hands and wrists. Loy told Reuters that he believes Otzi “was in a combat situation for between 24 to 48 hours before he died,” fighting off at least two foes, and that the blood found on the back of Otzi’s coat could have come from carrying a wounded companion.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 8/19/2003.

Having a problem with hornets bothering you at the family picnic? Perhaps it’s the perfume you’re wearing — or even the food you’re eating. Masato Ono of Tamagawa University in Tokyo and colleagues report in the August 7 Nature that chemicals found in fragrances and manufactured food can make hornets fly into a frenzy and attack. When hornets are threatened, they release alarm pheromones — chemical signals — that cause fellow hornets to attack defensively. The researchers analyzed the components of these pheromones and confirmed that they contain chemicals sometimes used in fragrances and in food flavorings and speculate that “it is possible that they might provoke a seemingly unwarranted hornet attack on humans.” They conclude, “It may therefore be sensible to screen these commercial products for the presence of pheromones that might act as an alarm signal to dangerous insects.”

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 8/12/2003.

More than 30 years ago, research by psychologist Stanley Milgram suggested that any person on the planet can be connected to any other person by an average of six social ties. This “small-world hypothesis” with its famed “six degrees of separation” caught on in popular culture, inspiring the Kevin Bacon game, where movie stars are connected through a chain of film work to the actor. And it seems to work for e-mail as well, report researchers in the August 8 Science. Peter Sheridan Dodds of Columbia University and his colleagues asked volunteers to attempt to reach 1 of 18 people from 13 countries by forwarding messages to acquaintances. Targets included a professor at an Ivy League university, an archival inspector in Estonia, and a vet in the Norwegian army. Of the more than 24,000 message chains that were generated, only 384 reached their target, but of those successful 384, just as in Milgram’s experiments, the searches took between 5 to 7 steps. There was evidence that the low chain completion was due to “individual apathy and disinclination to participate.” The researchers write, “if individuals searching for remote targets do not have sufficient incentives to proceed, the small-world hypothesis will not appear to hold, but that even a slight increase in incentives can render social searches successful under broad conditions.”

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 8/12/2003.