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Biomedical subjects

R L Tompkins

Publications and source records attributed to R L Tompkins.

4 recordsLinked to original sources

Relative dental development of Upper Pleistocene hominids compared to human population variation.

The relative development of permanent teeth in samples of Neandertal/archaic Homo and Early Modern/Upper Paleolithic hominids is compared to the range of variability found in three recent human samples. Both fossil hominid samples are advanced in relative M2 and M3 development compared to white French-Canadians, but only the Neandertal/archaic Homo M3 sample is advanced when compared to black southern Africans. Both fossil hominid samples are delayed in relative I1 and P3 development compared to the recent human samples. Two hypotheses concerning the significance of the advanced M3 and M2 development found in both hominid groups and southern Africans compared to French-Canadians are discussed. The first postulates that the differences in relative molar development are due simply to variation in tooth/jaw size relationships. The second postulates that the relatively advanced M3 and M2 development found in the fossil hominids and southern Africans is a correlate of their potential for advanced skeletal maturation compared to French-Canadians and other European-derived populations. It appears that dental development patterns have continued to evolve from the Upper Pleistocene to present times, and that Neandertals and Early Moderns shared similar patterns of relative dental development.

Animals↗

Human population variability in relative dental development.

Using dental X-rays, the calcification of various teeth was compared between samples of black southern Africans, white French-Canadians, and prehistoric Native Americans sharing the same stage of calcification of a specified "reference tooth." The French-Canadians have markedly delayed relative development of the M3 compared to the Africans. They also appear delayed in their M2 development compared to both the Africans and Amerindians. While no difference in relative mandibular canine development is found between the African and French-Canadian males, French-Canadian females are advanced over the African females. Prehistoric Native Americans may be delayed in mandibular central incisor development compared to French-Canadians. These results are in general accord with other studies of variability in dental development between Africans/African Americans, Europeans/European Americans, and Native Americans, and demonstrate that population differences in ages of eruption are attributable in part to differences in relative dental development. Two potentially falsifiable hypotheses concerning the significance of population variability in relative dental development are discussed: 1) the variability (at least for molars) is associated with the amount of space in the jaws for developing teeth, 2) the variability is due to population differences in the timing of dental and skeletal development.

Animals↗

La Ferrassie 6 and the development of Neandertal pubic morphology.

Functional interpretations of the mediolateral elongation and superoinferior flattening of the superior pubic ramus of Neandertals require knowledge of its ontogeny. Metric comparisons between the La Ferrassie 6 Neandertal infant, aged 3-5 years, and a sample of modern infants reveal that the acetabulosymphyseal length of La Ferrassie 6, relative to femoral length and iliac breadth, falls at the limits of the range of variation of the modern infants, while the relative height of its superior pubic ramus is indistinguishable from that of the modern sample. It appears that acetabulosymphyseal elongation of the Neandertal pubis is a feature which is expressed quite early in ontogeny, well before puberty. Superoinferior flattening and ventral margin thinning of the superior ramus probably appear later in Neandertal ontogeny.

Child, Preschool↗