Random Samples

Science  17 Mar 2006:
Vol. 311, Issue 5767, pp. 1531
  1. Human Quadrupeds

    CREDIT: BBC

    It sounds like something from an old-style circus: Four sisters and a brother who have walked on all fours since childhood. But it's gotten some scientists excited that the siblings could provide a clue to our evolutionary past. And the BBC is jumping in with a special, airing 17 March, on “the first human quadrupeds the modern world has ever seen.”

    The five are now young adults in a family of 19 living in a village in southern Turkey. Scientists from the nearby University of Cukurova began studying them in2004. Physiologist Uner Tan found that they are mentally retarded, with very limited vocabularies, and brain scans revealed atrophy in the cerebellum, the brain's motor area. A German-Turkish team published a DNA study online in the Journal of Medical Genetics in December 2005 that maps the quadrupedal trait to a particular locus on chromosome 17.

    In a paper in the March International Journal of Neuroscience, Tan postulates that the syndrome represents “a backward stage in human evolution” and may cast light on how speech and bipedality coevolved. Because the siblings walk on the palms of their hands, rather than on their knuckles, like apes, Tan hypothesizes that our hominid ancestors were palm-walkers.

    Researchers at the London School of Economics (LSE), who have also examined the family, have come up with a less dramatic interpretation. Evolutionary psychologist Nicholas Humphrey and colleague John Skoyles believe the condition is the result of a highly unlikely combination: cerebellar atrophy (which alone would not prevent bipedalism) and the whole family's unusual penchant for “bear walking”—using hands and feet instead of the usual knee crawl—in infancy. The LSE team brought in a physiotherapist, who was quickly able to teach the hand-walkers to walk upright. Nonetheless, Humphrey says the phenomenon could indeed supply “a model for how our ancestors might have walked.”

    Antharopologist Owen Lovejoy of Kent State University in Ohio throws cold water even on this idea, saying “people have been debating ancestral palm-walking for more than 100 years, but its emergence with this type of cerebellar dysfunction in modern humans does nothing to advance the argument.”

  2. Crystal Pattern

    CREDIT: UNIVERSITY OF WISCONSIN, MADISON

    Researchers at the University of Wisconsin, Madison, have devised a way to grow human embryonic stem (ES) cells on liquid crystals. The crystal is covered with a thin film of Matrigel, a culture medium. As the cells grow, they reorganize the Matrigel, changing the crystal's response to polarized light. Because differentiating cells exert more tension on the surface on which they are cultured than do undifferentiated ES cells, chemical engineer Sean Palecek and his colleagues hope to develop a tool that can identify differentiating cells while they are still alive. Currently, scientists use antibodies to identify cells, which usually requires killing them.

  3. A Crustacean Yeti

    CREDIT: MICHEL SEGONZAC/IFREMER

    What do you get when you cross a gorilla with a lobster? Probably something that looks like the 15-centimeter-longhairy crustacean found near deep-sea vents in the southern Pacific last year. Officially known as Kiwa hirsuta, but dubbed the “Yeti crab,” the creature is described in the current issue of Zoosystema by its discoverers, a team led by marine biologist Michel Segonzac of the French Research Institute for Exploitation of the Sea in Paris. The animal's unusual appearance and DNA qualify it as the first new family of decapods—10-legged crustaceans that include lobsters and crabs—in a century. The lobster lacks eyes, so its “hairs”—actually extensions of its exoskeleton—may be used for sensing. “This is an amazing find,” says Richard Lutz, a marine biologist at Rutgers University in New Brunswick, New Jersey. “What I would most like to know about this beast is how ancient its lineage is.”

  4. Jupiter's Red Spot #2

    CREDIT: CHRISTOPHER GO

    Original (left) and new (right) spots.

    The world has long been familiar with Jupiter's “Great Red Spot,” a swirling storm twice as wide as Earth that's lasted for at least 300 years. Now it may have a rival. In 2000, scientists spotted a large, white-colored oval on Jupiter, the product of three smaller storms merging. But it took amateur astronomer Christopher Go of the Philippines to notice that the spot, dubbed Oval BA, morphed from white to grayish-brown in December. Since late February, it has taken on the rusty red hue of its larger sibling.

    Scientists aren't sure of the reasons for the change, says astronomer Glenn Orton of the Jet Propulsion Lab in Pasadena, California. He and others hypothesize that particularly violent storms propel material from under Jupiter's clouds higher into the atmosphere, where the sun's radiation then sparks a chemical reaction to turn the material red. Other jovian white spots have temporarily turned red in the past; astronomers are curious to see if this one lasts.

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