2000 March 16

PLEASE NOTE: This background material is NOT submitted for publication.

It is being provided solely to assist in verifying the factual basis of the submitted material entitled "48 Chromosomes" by Bruce A. Martin.

I intend to use some of this material in a future piece I am developing further on the theme of "scientific conformity." Written for the intelligent layman, the piece will cite numerous instances when otherwise-honest and reputable scientists have staunchly defended their "truth" in the face of mounting evidence to the contrary. The 48-chromosome incident may have been my first personal encounter with this phenomenon (which I label "epistemological inertia"), but it was hardly the first nor the last of such episodes in the history of science.

Mr. Sygoda, my Biology teacher in High School, described his subject as "an observational science," unlike Physics and Chemistry, in which calculations can be made from a mathematical formula. However, he predicted that, within our lifetimes, advances in understanding (as well as in Chemistry and Physics) would transform Biology into a true science, complete with theoretical underpinnings, mathematical formulae, and the ability to predict consequences. He noted that some of these advances were already underway. He also taught us that the number of "chromosomes" in the nucleus of the human cell was the same as the number of stars on the flag, but that they were arranged not in a 6x8 rectangular pattern but in two dozen pairs.

That was in 1957. He was already slightly out-of-date with his facts, but his predictions were quite prophetic.

Since the 1920s, every qualified researcher "knew" that the number of human chromosomes was forty-eight, and most of them had been able to see them all with the aid of microscopes. When colored dye is injected into the microscope slide, it is absorbed by certain structures in the cell nuclei - giving them characteristic bands to make them easier to distinguish and, incidentally, giving them their colorful name. (The prefix "chromo" means color.)

Despite dyeing, it is exceedingly difficult to distinguish them in a three-dimensional cell nucleus. No wonder that the count was incorrect until the mid-1950s, when advent of "tissue culture" techniques for promoting the controlled multiplication of selected cells within sealed capillary tubes. It was not until about 1956 that the incorrect number for humans was revised downward by one pair, to forty-six. This loss, however, was in some ways offset by the admission to the Union of Alaska and Hawaii in 1958 and 1959, respectively.

Alas, it was chimpanzees that retained the count of 48 chromosomes. However, they do not have any flags. Neither do horses; however, their chromosome number is a perfect square: 64. (The human chromosome count is the horse count, read backwards.)

Presumably, the news of this revision had not quite trickled down to High School teachers such as Mr. Sygoda, by the Fall of 1957. More significant to his prediction was the 1954 breakthrough by Francis Crick and James Watson in determining the stereochemical structure of DNA, which comprises the chromosome.

I am privileged to have met and spoken at length to both these men. Separately. (They have not spoken much to each other in recent years, and seem to avoid mentioning or contacting each other.) Much of their work was based upon that of Isidore Fankuchen, who determined the structure of the Tobacco Mosaic Virus in 1937 [approx.]. In the months preceeding his death, "Fan" was my thesis advisor, when I was beginning my studies in the field of Crystallography. It was he who acquainted me with the fact that error in the calibration standards, which haunted textbooks for decades, and which required the creation of "the X unit" (as a fudge-factor for the Angstrom), originated in a computational error made by none other than Rutheford. But that is yet another story.