Sexual Dimorphism in Antropology

Using the technique of generalized photo portrait, a distinct sexual dimorphism has been found in the Turkmen’s population: there is just one type of female portrait and two types of male portraits (Pavlovski, 1980). Similar phenomenon has been found in craniology of Bashkirs: there was a monomodal distribution of characters for female skulls and tetra modal distribution for male skulls (Yusupov, 1986). Same pattern has been identified based on dermatoglyphics: when females had a form of just one adjacent ethnic group and men had a form characteristic of another adjacent ethnic group. In Udmurt population females had Volga-Vyatka region type (N.-W.) of dermatoglyphics, while males—of E.-Siberian type (Dolinova, 1989). Also Kavgasova noted resemblance in dermatoglyphics between Bulgarian and Turkish men, while women were close to Lithuanian type.

Population	Type of Phenotype
Population	Women	Men
Bashkirs	1 type	4 types
Udmurts	1 type (“N.-W.”)	1 type (“E.-Siberian”)
Bulgars	1 type (“Lithuanian”)	11 type (“Turkish”)
Japanese	1 type	1 type

These paradoxes get natural explanation from the new theory. Transmission of genetic information from parents to their progeny can occur through four channels: mother → daughter, mother → son, father → daughter и father → son. Common part of information (I_common), which is the same for both sexes, is transmitted stochastically through all four channels. Therefore it is mixed fast and is distributed homogeneously in both sexes.

“New” ecological part of information (I_new), that is in the male sex already, but not in the female sex yet, is transmitted through the male line only (father → son). This way it is delayed in the male subsystem for some time. Another, “old” part of information (I_old), which was already lost by the male sex, but still present in females, transmitted through the female line only (mother → daughter). The information contained in the male genome is I_male = I_common + I_new , whereas the information in the female genome is I_female = I_common + I_old . The lifetime of “new” and “old” information is significantly more than a life time of one generation, therefore different results will be observed depending on how the mixing of ethnoses was happened.

Symmetric hybridization. At symmetric hybridization the contribution of man and woman’s genotypes from both ethnoses into hybrid posterity is identical. Each ethnos provides all three genetical parts—common, man's and woman’s. As only the general part of the information quickly mixes up in hybrid ethnos, there should be two types of men and women. Since distinctions between initial ethnoses frequently have divergent character man's types will be more precisely allocated.

Asymmetric hybridization. If mixing of ethnoses occurs asymmetrically, so that two genders from one ethnos participate in hybridization, and only one gender—from another ethnos, then two different scenarios are possible. In the first case there can be 2 types of men and 1 type of women in the hybrid posterity (the conqueror - man in the defeated country), because the “old” part of the information (explicitly female) from the ethnos – conqueror is missing.

In the second case, on the contrary, there will be 1 type of men and 2 types of women (the captured women brought into the country of the conqueror), because the missing part will be “new” (man's of the defeated ethnos). Thus in an area of hybridization the geographical change of sexual dimorphism can be observed which can be linked with a historical direction of migrations.

It is interesting to note, that the island population (Japanese) in full conformity with the theory appears monomodal for both sexes. Hence, population sexual dimorphism can serve as another genetic criterion for verification of historical and ethnographic concepts. Thus it can be not only morphological (for example, on dermatoglifics, epicanthus etc.), but also a physiological (for example by a spectrum of groups of blood, enzymes, antibodies), ethological or psychological.

This concept provides a natural and simple explanation of the differences, of inter-specific, inter-racial, or international reciprocal hybrids which are related to the hybridization direction, because the reciprocal hybrids possess the common I_common , and get I_new and I_old from different forms (compare the hinny and mule). If the descendants obtained identical information from the father and mother, then there should be no reciprocal phenomena.

Dolinova, N.A., Dermatoglyphics of Udmurts, New Studies on Ethnogenesis of Udmurts, 1989, Izhevsk: Uro Acad. Sci. SSSR, pp.108-122.

Pavlovskii, O.M., Generalized Photoportrait: What Does It Tell? Nauka i Zhizn', 1980, no.1, pp.84-90.

Yusupov, R.M., About Sexual Dimorphism and Significance of Female Samples of Skulls in Anthropology, in Jstochniki po istorii i kulture Bashkirii (References on History and Culture of Bashkiria), Ufa, 1986, pp.51-56.