GOLLYGEE!

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Year: 2012 (page 7 of 55)

11.29.2012

why the mean girls are so pretty

Julie Beck reports in Popular Science:

The meanies aren’t necessarily more physically attractive than anyone else, they are just better at using what the study calls “adornments” (clothes, makeup and the like) to make themselves seem more appealing. The researchers, Nicholas Holtzman and Michael Strube at Washington University in St. Louis, had their subjects remove all makeup, pull long hair back into a ponytail and don a white T-shirt and grey sweatpants. They were rated on their attractiveness in this unadorned state, set loose to adorn themselves to their hearts’ content, and rated again. All three Dark Triad traits were associated with higher attractiveness inthe adorned state, when controlling for attractiveness in the unadorned state. So you can take some small comfort in knowing that mean people are just as ugly as the rest of us, they’re just better at fooling everyone into thinking they’re hot.

The study suggests a possible reason why these subjects were compelled to make themselves more attractive: “When people high in Dark Triad [i.e. mean] traits dress-up, they may experience greater increments in self-esteem or derive more satisfaction from the additional attention they receive, compelling them to continue dressing well.”

Also see Scientific American.

11.28.2012

the immortal jelly fish

Turritopsis dohrnii

Turritopsis dohrnii, the immortal jellyfish.

he New York Times has an interesting (and long!) piece about a jellyfish species that appears to live forever. An excerpt:

Sommer was conducting research on hydrozoans, small invertebrates that, depending on their stage in the life cycle, resemble either a jellyfish or a soft coral. Every morning, Sommer went snorkeling in the turquoise water off the cliffs of Portofino. He scanned the ocean floor for hydrozoans, gathering them with plankton nets. Among the hundreds of organisms he collected was a tiny, relatively obscure species known to biologists as Turritopsis dohrnii. Today it is more commonly known as the immortal jellyfish.

Sommer kept his hydrozoans in petri dishes and observed their reproduction habits. After several days he noticed that his Turritopsis dohrnii was behaving in a very peculiar manner, for which he could hypothesize no earthly explanation. Plainly speaking, it refused to die. It appeared to age in reverse, growing younger and younger until it reached its earliest stage of development, at which point it began its life cycle anew.

Sommer was baffled by this development but didn’t immediately grasp its significance. (It was nearly a decade before the word “immortal” was first used to describe the species.) But several biologists in Genoa, fascinated by Sommer’s finding, continued to study the species, and in 1996 they published a paper called “Reversing the Life Cycle.” The scientists described how the species — at any stage of its development — could transform itself back to a polyp, the organism’s earliest stage of life, “thus escaping death and achieving potential immortality.” This finding appeared to debunk the most fundamental law of the natural world — you are born, and then you die.

Read the whole thing. It’s really worth it.

11.27.2012

tracing the origins of chickens

Photograph of a chicken. Image from PLOS via Scienceblogs

Researchers are interested in tracking down the genetic origins of today’s domesticated chickens. From Science:

Their genes, and those of other isolated populations, are now being sequenced (see sidebar, p. 1022) as part of a larger effort to understand the world’s most common bird and biggest source of animal protein. In 2009, Americans ate 36 billion pounds of chicken, and the numbers keep growing, especially in developing countries in Asia and Africa. That importance is highlighted by the fact that the chicken was the first farm animal to have its genome published, back in 2004. Since then, the proliferation of factory farms, mass bird deaths from avian influenza, and dwindling diversity in chickens have raised concerns about this critical source of food.

A key thrust of research in the past decade has been to track the genetic changes that turned a remarkably shy creature into today’s meat-and-eggs dynamo, with an eye to protecting and improving breeds. But this research has also given scientists the opportunity to unravel a long-standing mystery that fascinated Charles Darwin: Where, when, and how was the chicken domesticated?…

The advent of sequencing tools in the 1990s promised a new line of evidence that went beyond physical characteristics. The results, however, have only heightened the controversy. A draft of the chicken genome, for example, isn’t enough to trace the bird’s evolution: Researchers need ancestral birds for comparison. Geneticists first used mitochondrial DNA (mtDNA) to trace the female line of the species back to its origin. Akishinomiya Fumihito, an ornithologist and prince in Japan’s royal family, extracted sections of mtDNA from Thai red jungle fowl and asserted in a 1994 paper that the findings suggested a single domestication in Thailand. Eight years later, another team used mtDNA from native Chinese chickens to support that idea.

In 2006, however, a team led by Yi-Ping Liu of China’s Kunming Institute of Zoology found nine separate clades—that is, groups descended from a common ancestor—in the mtDNA of a large sample of wild and domestic modern birds. The distribution of the clades suggests a distinct and separate expansion of lineages in southern China, Southeast Asia, and the Indian subcontinent, supporting a multiple origins theory. Another team published a study this week in Heredity based on nuclear DNA, which is not limited to the maternal line, supporting that view.

Much more at the source link. [Subscription may be required.]

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