Boros István (szerk.): A Magyar Természettudományi Múzeum évkönyve 52. (Budapest 1960)

Thoma, A.: Anthropometric characters and selective survival

ANNALES HISTORICO-NATURALES MUSEI NATIONALIS HUNGARICI Tomus 52. PARS ANTHROPOLOGIC* 1960. Anthropometric characters and selective survival By A. THOMA, Budapest Introduction The combinations of certain characters of the human organism which depend on pleiotropic factors are most peculiar and unexpected. They bring into hereditary association characters between which no structural or functional correlation whatever may be surmised. A case in point is the blue sclera and the abnormal fragility of the bones, both of which are due to the same factor. The unusual nature of these correlations rests obviously on the fact that with the intricate human organism the process of how development is canalised and co-ordinated in the early phases of ontogeny is altogether unknown. The constitutional type may be conceived as being the most general suchlike association of characters. Also the constitutional correlations are for the most part unexpected and unexplained, as for instance the association of the squat, oval hand form and the liability to circular insanity. On the other hand, we know that in the determination of the length of life too hereditary and constitutional factors play an important part. Examining the causes of remarkably high age, Pearl (4) states that "... the eliminated and the survivors are biologically (constitutionally) differentiated one from the other in respects other than their duration of life". The most frequent causes of death differ from each other also in the various phases of adult age. With respect to hereditary factors this means that in each period of life selection eliminates different genotypes. The chances of attaining a certain age vary from genotype to genotype. We may suppose with good reason that owing to the aforementioned genetic correlations, selective death, or rather the phenomenon of survival at various ages, bears likewise on certain characters which are interesting also from an anthropological point of view. In other terms : certain external, somatic characters influence individual viability. The question thus propounded is not limited to genetics and gerontology alone : indeed, since selective death asserts itself presumably also within the age of reproduction, its investigation is interesting likewise in respect of human evolution. As in many other fields, also in the study of selective survival pioneering work has been done by H o o t o n (2). Basing to the data of the comprehensive Irish anthropometric survey, and for numerous metric and descriptive features, he tried to assess by subjective estimation how far the divergencies between the different age groups of adult age were referable to actual age changes, and how far to selective survival. For certain quantitatively denotable characters we shall endeavour in the following to measure more accurately the influence of these two factors. Methods and materials In a population comprising the age groups of adult age and of one of the sexes, the variations of a metric character are determined by the following factors : genetic and peristatic heterogeneity, age changes, and selective survival. Utilizing the additive property of the variances, we can express this by the following formula : al = oi + a\ + o% (1) where