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Biomedical subjects

J V Neel

Publications and source records attributed to J V Neel.

At least 217 records · Page 12Linked to original sources
PubMed1970

Village and tribal genetic distances among American Indians, and the possible implications for human evolution.

Pair-wise genetic distances based on six genetic systems (Rh, MNSs, Kidd, Duffy, Diego, and haptoglobins) are presented for seven villages of Makiritare Indians, seven villages of Yanomama Indians, and 12 Indian tribes of Central and South America. It is shown that the mean genetic distance between Indian villages is 85-90 per cent of the distance between tribes. Since in the past, the initial event in the formation of a new tribe was probably the breaking away of one or several related villages from an established tribe, it is clear that this initial event could have profound consequences for subsequent tribal gene frequencies. By the criterion of changes in gene frequency in polymorphic genetic systems, the maximal rate of evolution in the American Indian has been approximately 100 times more rapid than the mean rate suggested by calculations based on amino acid substitutions in certain polypeptides of a variety of organisms. The above-mentioned findings could account in part for this 100-fold difference. Some other factors which might diminish the apparent difference between the results of these two types of calculations are mentioned.

Acculturation↗
PubMed1970

Chromosome aberrations among the Yanomamma Indians.

The chromosomes of leucocytes cultured from the peripheral blood of 49 primitive Yanomama Indians of Venezuela were studied to determine the types and frequencies of aberrations in a human population not exposed to the same exogenous agents as civilized man. In all but one instance, 100 cells per individual were scored. In 13 cases, we found one or more cells with multiple complex breaks and rearrangements, represented by tetracentric, tricentric, and numerous dicentric chromosomes. From the standpoint of chromosomal damage, these cells are among the most abnormal cells yet described in vivo in man, and were not seen in the controls. There was also a higher than expected frequency of cells with an isolated structural aberration in both Indians and controls. This may be the result of a 24- to 48-hour delay in the initiation of culture. The cause of the more extensive damage to some cells remains to be determined.

Asian People↗
PubMed1970

Evaluation of the effects of chemical mutagens on man: the long road ahead.

By analogy with the problem of evaluating the genetic risks of radiation, it appears that it will be extremely difficult to assess the mutagenicity for man of the wide range of chemicals to which human populations are currently exposed. Nevertheless, the potential significance of this problem calls for a major effort at such an evaluation.

Animals↗