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No. 111: May-Jun 1997

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Chromosome Choreography

Every biology student has seen sketches of the "dance of the chromosomes" that is performed when eukaryote (nucleuscontaining) cells divide. Because chromosomes are composed of genes and their DNA -- the information carriers of inheritance -- it reasonable to suppose that they are the "dance-masters." This expectation is enhanced if one holds that the genes are "selfish;" that is, they have their own evolutionary agendas, and all life forms exist only to execute their "will."

But cell division would not occur at all without the action of the cell's bipolar spindle. This spindle is composed of microtubules -- rods of the protein "tubulin." Somehow, when cells are about to divide, they synthesize these microtubules, which then seem to organize themselves into orderly arrays (the bipolar spindles). Then, the microtubules sort out and separate the two sets of chromosomes required for the two new cells. So, far, our description conforms to what biologists have known and accepted for decades; but there is something more mysterious going on.

In 1996, researchers discovered that they can actually substitute DNAcovered beads for the chromosomes, and the microtubules will still go through the motions of sorting and separating the chromosome-less strands. Actually, the microtubules will perform their act even without the DNA-covered beads. In a sense, the bipolar spindle is a puppetmaster, and the microtubules are the strings. The puppet show can go on without the puppets (chromosomes).

(Hyams, Jeremy; "Look Ma, No Chromosomes," Nature, 382:397, 1996. Also: Heald, Rebecca, et al; "Self-Organization of Microtubules into Bipolar Spindles around Artificial Chromosomes...," Nature, 382:420, 1996. Travis, John; "Mitotic Mischief," Science News, 150:14, 1996.)

Comments. Obviously, neither the chromosomes, the genes, nor the DNA are the master of the show. They are merely passive players in cell division. It is fair, therefore, to ask how these microtubules originate and operate. Whence the information and instructions ("program") required to put on the show? "Self-organization" is the current answer of mainstream biologists, but this term has no explanatory value.

Microtubules separating chromsomes prior to cell division Microtubules separating chromsomes prior to cell division. Left: early anaphase. Right: late anaphase.

From Science Frontiers #111, MAY-JUN 1997. 1997-2000 William R. Corliss

Science Frontiers Sourcebook Project Reviewed in:

Quotes

  • "A sourcebook of unexplained phenomena is therefore a valuable addition to a collection of scientific literature. William R. Corliss has provided this in the past with his source books of scientific anomalies in several subjects, and now he has provided it for astronomy. He has done an excellent job of collecting and editing a large amount of material, taken in part from scientific journals and in part from scientific reporting in the popular or semi-scientific press." -- "The Mysterious Universe: A Handbook of Astronomical Anomalies", reviwed by Thomas Gold, Cornell University, in Icarus, vol.41, 1980

  • "An interesting, systematic presentation of unusual weather [..] This book is recommended for a general audience" --"Corliss, William R., Tornados, Dark Days, Anomalous Precipitation, and Related Weather Phenomena, Sourcebook Project, 1983.", revieweed in Choice, September 1983
  • "..the science is necessarily somewhat speculative, but Corliss's symthesis is based on reputable sources." -- "Corliss, William R. (Compiler). Lightning, Auroras, Nocturnal Lights, and Related Luminous Phenomena" reviwed by Joseph M. Moran, Univ. of Wisconsin in Science Books and Films, Sep/Oct 1983

  • "Before opening the book, I set certain standards that a volume which treads into dangerous grounds grounds like this must meet. The author scrupulously met, or even exceeded those standards. Each phenomenon is exhaustively documented, with references to scientific journals [..] and extensive quotations" -- "Book Review: The moon and planets: a catalog of astronomical anomalies", The Sourcebook Project, 1985., Corliss, W. R., Journal of the Royal Astronomical Society of Canada, Vol. 81, no. 1 (1987), p. 24., 02/1987