Word: biologist
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...Himalayas; manned voyages to space have become commonplace; and robot probes have ventured to the outer reaches of the solar system. But only now are the deepest parts of the ocean coming within reach. "I think there's a perception that we have already explored the sea," says marine biologist Sylvia Earle, a former chief scientist at the National Oceanographic and Atmospheric Administration and a co-founder of Deep Ocean Engineering, the San Leandro, California, company where construction of Deep Flight I began: "The reality is we know more about Mars than we know about the oceans...
...Recalls biologist Holger Jannasch, at Woods Hole in Massachusetts: "I got a call through the radio operator at Woods Hole from the chief scientist . who said he had discovered big clams and tube worms, and I simply didn't believe it. He was a geologist, after all." Disbelief was quickly replaced by intense curiosity. What were these animals feeding on in the absence of any detectable food supply? How were they surviving without light? The answer, surprisingly, had been found by a Russian scientist more than 100 years earlier. He had shown that an underwater bacterium, Beggiatoa, lived on hydrogen...
...Switzerland. They have discovered that genes associated with the formation of fins in fish are the same ones that orchestrate the development of paws in mice. "Think of a mouse as a fish with limbs, or a fish as a mouse with fins," says University of Geneva developmental biologist Denis Duboule. "What a mouse does is take a fin and put something extra...
...past decade have scientists begun to tease apart the mysteries of Hox genes. Clustered in groups of eight to 11, on as many as four chromosomes in a developing embryo's cells, these genes switch on and off in sequence. Since embryos mature from the top down, explains biologist Cliff Tabin of the Harvard Medical School, a Hox gene that turns off a bit early, or stays on just a touch longer, can make a dramatic difference in the formation of the embryo. Swans, for example, have more neck vertebrae than chickens and thus longer necks. That is because...
...convince scientists that Duboule and his colleagues have correctly solved the fins-to-feet riddle. Other factors could be involved as well, including homeobox genes that are not Hox genes (that is, they do not affect the overall structure of an animal). Last year Sean Carroll, a developmental biologist at the Howard Hughes Medical Institute in Madison, Wisconsin, showed that a homeobox gene involved in insect-limb formation also controls the genetic signals that paint spots on butterfly wings. In essence, says Carroll, butterflies use an old gene to perform a new trick. "Evolution did not have to invent...