Word: dna
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Dates: during 1990-1999
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That something extra, Duboule and his colleagues suggest in the journal Nature, is provided by a special set of genes that act as master architects in a surprisingly broad range of animals, from rodents to roundworms. These gossamer strands of DNA -- known as homoeotic homeobox genes, or Hox genes for short -- lay out the embryo from head to tail, controlling everything from the development of limbs and the wiring of the spinal cord to the patterning of the gut and urogenital tracts. "What's amazing," says University of Pennsylvania paleontologist Neil Shubin, "is that evolution of complex structures appears...
...genes pack such power? The DNA in all genes carries instructions for assembling proteins out of chemical building blocks called amino acids. What sets the proteins made by Hox genes apart is the biochemical motif known as a homeobox, a stylized string of 60 amino acids that enables Hox proteins to stick to DNA like strips of molecular Velcro and, in the process, activate still other genes. Hundreds of genes belong to the extended homeobox family, but those that are also homoeotic -- associated with changes in body parts -- are the most important. Though they are few in number...
...there is no shortage of competing theories about how consciousness might arise. One, offered by the Salk Institute's Francis Crick (co-discoverer of the structure of DNA) and Christof Koch, at the California Institute of Technology, is that consciousness is somehow a by-product of the simultaneous, high-frequency firing of neurons in different parts of the brain. It's the meshing of these frequencies that generates consciousness, according to Crick and Koch, just as the tones from individual instruments produce the rich, complex and seamless sound of a symphony orchestra. The concept is highly speculative, Crick acknowledges...
...Phase 4, the defense would attack the prosecution's dna evidence. But since one of the prosecution's own expert dna witnesses admitted to errors on the stand, Simpson's lawyers may choose to limit testimony here. Also, Nobel laureate Kary Mullis, the team's star witness on flaws in the dna-testing procedures -- which he partially invented -- is a loose cannon who might say anything...
...second week, testimony also focused on Simpson's cut finger, which the defense maintains was injured when the defendant broke a drinking glass in his Chicago hotel room upon learning of his ex-wife's death. A principal challenge still looms: the defense must address voluminous physical evidence, including DNA and fiber samples, at the heart of the prosecution's case...