Counseling in medical genetics / Sheldon Reed.

  • Sheldon Clark Reed
Date:
[1980]
Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Counseling in medical genetics / Sheldon Reed. Source: Wellcome Collection.

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    6 / Our Distant Relatives The cover of the July 20, 1979 (vol 205), issue of Science had a color picture of the first one of the two hybrids, a healthy three-year-old female. This work suggests that chromosomal rearrangements have occurred quite rapidly in these lesser apes and that there exists a greater genetic distance between them than that which distinguishes the great apes from one another and from man. This is exciting because it suggests that healthy hybrids might be produced be¬ tween different genera of the higher primates now that all of us live rather happily together at zoos and circuses, among other places. Crosses between chimpan¬ zees and gorillas, for example, would have to be done by artificial insemination, if at all, because these two genera have such different hfe styles. Dutrillaux and Rethoré [1975] compared the chromosomes of the pygmy chimpanzee (Pan paniscus) with those of the ordinary chimpanzee (Pan troglodytes) and found them to be very much alike. Twenty pairs seemed to be completely analogous in the two species. Presumably a fetus would be produced and perhaps a viable hybrid could be obtained from a cross of these two chimpanzee species by artificial insemination. The frontispiece of this book comes from a study by Warburton et al [1973] in which the chromosomes of the chimpanzee (Pan troglodytes) were compared with human chromosomes. The banding patterns in the two species are so similar that the homologies seem clear in spite of minor differences. In the photo¬ graph the chromosome on the left of each pair is a human chromosome, and the chromosome on the right is presumably the homologous chimpanzee chromosome. The human chromosome 2 corresponds to two chimpanzee chromosomes, numbers 13 and 17, and accounts for the fact that chimpanzees have 24 pairs of chromo¬ somes while people have only 23 pairs. They suggest that the short arm of human chromosome 2 corresponds to the long arm of chimpanzee chromosome 17, where¬ as the long arm of human chromosome 2 corresponds to all of chimpanzee chromosome 13. It is thought that the Pongidae (Pongo, Corrila, Pan) separated from the Hominidae some 25 million years ago. Probably chimpanzees, gorillas, and man have been drifting apart for from six to twelve milhon years. Nonetheless, the chromosome banding patterns have remarkable similarity. Chromosomally speaking, one might expect that it would be possible to have Pan-Homo hybrids produced by artificial insemination, as the chromosome differences are much less obvious than those found in the siabon hybrid described above. Interest in possible hybrids between Homo and Pan is not frivolous. A vast amount of work has been done on the biochemistry, anatomy, physiology, behavior, and ecology of the two species. The genetics of the hybrid would be most instructive for us from many points of view. We know already that the geno¬ types of the human and the chimpanzee are as similar as those of sibling species of other organisms. King and Wilson [1975] discuss the paradox of why two species with such similar genes differ so substantially in anatomy and way of life.
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