Random Samples

Science  10 Aug 2001:
Vol. 293, Issue 5532, pp. 1043

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  1. Skulls Suggest Two New-World Migrations

    Anthropologists still debate how and when the first people migrated to the Americas across the Bering Strait. Now a new theory, based on skull measurements, has been tossed into the speculation pot. It suggests that there were two major migrations to the New World: the first involving people who resembled the Kennewick Man and the second of people from mainland Asia.

    Conventional wisdom holds that Native Americans are descended from Asians who came across the Bering Strait about 11,000 years ago. But anthropologists have long suspected that humans migrated to the New World more than once. Linguistic studies offer support for this theory; genetic and archaeological studies have been equivocal.

    Now an analysis of 2000 skulls ranging from 100 to 10,000 years old adds data to the controversy. Anthropologist C. Loring Brace of the University of Michigan, Ann Arbor, and colleagues in China, Mongolia, and Wyoming measured 21 cranial characteristics in people from 19 major groups from around the world. (Kennewick Man, still tied up in litigation, was not in the group, although, says Brace, “I wanted to get my calipers on that thing.”)

    The measurements, coupled with archaeological data, suggest that the earliest migration occurred about 15,000 years ago. The team, reporting in the 14 August Proceedings of the National Academy of Sciences, claims that most Native Americans are descended from this group, which seems to be most closely related to two Caucasoid Japanese indigenous populations, the Jomon and Ainu. A second group of migrants descended from Asian mainlanders who crossed the Bering Strait beginning 5000 years ago, giving rise to North American Eskimos and possibly Navajos as well, says Brace.

    The study is a “rigorous” one with an unusually large data set, says anthropologist Richard Jantz of the University of Tennessee, Knoxville. But University of Michigan geneticist D. Andrew Merriwether is skeptical: The researchers, he says, assume— incorrectly—that there is a firm link between skull shape and genetic heritage.

  2. What About a Smart Banana?

    How do Brits like the idea of being able to eat tropical fruits grown locally? That's one thing the U.K. government is trying to find out with a new Internet questionnaire that aims to survey what the average man on the Web thinks of future foods, including genetically modified (GM) products.

    The Biotechnology and Biological Sciences Research Council is asking participants about five potential new products: Scotland-grown bananas; no-calorie cake; anticancer broccoli; lasagna that keeps for months at room temperature; and “smart” labels that could detect when something's gone bad.

    A council spokesperson says that so far, people have been quite keen for the zero-calorie cake, which is described as having “intelligent” slow-release ingredients that resist digestion, although one thoughtful respondent asked: “What about the faeces resulting from this product class?” Smart labels also drew positive reactions, even though these would require special scanners and appliances that could read the labels' cooking instructions.

    The long-lived lasagna, however, has met with some skepticism: “It's bad enough having frozen meals which only last a couple of months—god forbid we have things that last years!” wrote one consumer. As for anticancer broccoli, wrote another, “How many people actually LIKE broccoli?” And Scottish bananas are definitely not the wave of the future: They stir up anti-GM sentiments, and besides, noted one writer, “growing them in this country makes them more commonplace and boring.”

  3. Spotting the Suicidal Poet

    It may be possible to detect a poet's suicidal tendencies by parsing their poems, claims a paper published in the July/August issue of Psychosomatic Medicine. It says poems by people who later killed themselves reflect more self-preoccupation and isolation than do those of a control group.

    There are several theories about suicide: Sociologist Emile Durkheim theorized that the key is an individual's lack of bonding with a social group; a more traditional model emphasizes hopelessness and helplessness.

    Psychologist James W. Pennebaker of the University of Texas, Austin, and Shannon Wiltsey Stirman of the University of Pennsylvania in Philadelphia tested these theories on nine American, Russian, and British poets, all but one from the 20th century, who had committed suicide. The ill-fated wordsmiths were matched with contemporaneous poets of the same sex and nationality.

    The researchers analyzed about 300 poems using software that quantifies word use and meaning. They tested Durkheim's theory by looking for references to self and others, and to communication. Hopelessness, they decided, would be marked by mentions of death and negative emotions.

    The researchers note that many of the control poets shared depression and other mood disorders with the ones who committed suicide, and indeed there was no difference between the two groups when it came to mentions of positive or negative emotions. But the authors claim that the suicidal poets used “more first-person-singular self-references throughout their careers” and seemed more detached from others, thus backing the Durkheim model. For example, in the work of Sylvia Plath, who killed herself in 1963, “there are 'I's everywhere,” says Pennebaker. And near their deaths, troubled poets signaled increasing isolation by their infrequent use of “we.”

  4. Clone Homework Skimped

    This “may be the lowest level of knowledge I've seen … for a significant piece of legislation.”

    —Representative Peter Deutsch (D-FL) commenting on his colleagues' preparation for a 31 July House of Representatives vote to ban all human cloning, including “therapeutic” cloning with somatic cell nuclear transfer.