Brachycephalization

Brachycephalization (from other Greek. Βραχύς “short” and ϰεφαλή “head”) is the process of changing the shape of a person’s head towards high values ​​of the head index , which occurs in certain populations over a certain period of time. The result of this process is the gradual expansion and rounding of the skull ^[1] . Contrasted with dolichokephalization - the process of reducing the values ​​of the head pointer ^{[2] [3]} .

Brachycephalization in a series of processes of a long-term change in anthropological signs and properties of a person, such as gracialization or epoch-making acceleration refers to the processes of epoch-making variability ^{[4] [5]} . Like most such processes, brachycephalization is recorded according to the study of paleoanthropological materials . Thus, studies of the fossil remains of humans in the Paleolithic show the absolute predominance of dolichokephaly in humans during this era. Mesobrachicranian skulls appear only in the Late Paleolithic - in the Solutra . In finds, approaching in time to the Neolithic period , there is an increasing change in the size of the skulls in the direction of brachykran values . In the material of the Neolithic excavations, whole series of brachicran skulls are already presented. Later, in the Middle Ages , beginning in the second half of the 2nd millennium A.D. e. , the rate of brachycephalization is markedly accelerated ^[1] . Meanwhile, in some regions of the planet from the 1950-1970s, debrachycephalization began to be noted - the values ​​of the head pointer began to return to lower indicators ^[6] .

Brachycephalization is observed in a large number of human groups and populations , the continuity of changes of which can be traced for a long time ^{[2] [3]} . The most widely observed brachycephalization is in Northern Eurasia . This process is less common in North America (among the Indians ), the Middle East and North Africa . A number of areas of brachycephalization practically did not affect - mainly tropical regions of South Asia and Oceania , as well as African regions inhabited by representatives of the black race ^[1] . In contrast to brachycephalization, the reverse process, dolichokephalization, is relatively rare in humans ^{[2] [3]} .

There are a number of assumptions that explain the causes of brachycephalization, but there is no universally accepted hypothesis in modern anthropology . Brachycephalization, most likely, is part of the evolutionary process of spherical skull ^{[1] [2] [3]} .