Wednesday 1 August 2012
The Hominini is a tribe of the subfamily Homininae; it comprises three subtribes:
Hominina, with its one genus Homo;
Australopithecina, comprising several extinct genera (see taxobox);
Panina, with its one genus Pan, the chimpanzees.
Members of the human clade, that is, the Hominini, including Homo and those species of the australopithecines that arose after the split from the chimpanzees, are called hominins.
The role of the brain in the somatic development, as well as in the establishment of the different variables of the life history pattern in vertebrates has been largely debated.
Moreover, during the last thirty years, dental development has been used as a good proxy to infer different aspects of the life history in hominins, primarily due to the correlation that exists between age at first molar eruption and brain size in the order Primates.
It has been assumed that the brain represents the pace-maker of our development. However, it has been considered that our particular phenotype is the result of a hierarchical genetic program modulated by epigenetic and environmental factors.
The particular bauplan of any kind of organisms (e.g. primates) may explain the high correlation observed between different variables of its life history pattern, brain size or dental development.
However, the correlation of these variables seems to be less reliable when dealing with low-rank taxonomical categories (i.e., species).
It has been suggested that, while there is likely some relationship between the rate of somatic development and tooth development, our brain size and maturation (and, by extension, those of other species of the genus Homo) have derived towards a particular trajectory, with a unique pattern of prenatal and postnatal time and rate of growth and, particularly, with remarkable slow brain maturation. (25992637)
It has been suggested that extremely slow brain maturation could be a very recent acquisition of the last Homo sapiens populations. (25992637)
Review of the literature suggests caution in drawing conclusions about aspects of the life history of the hominins from the information that can obtain from dental development in fossil specimens. (25992637)