In the previous number of years, the presumption of many paleoanthropologists that early human forefathers had an extended infancy period much like that of modern people has been questioned by research studies based on two sorts of tooth analysis. One opportunity of this dental work, states B. Holly Smith of the University of Michigan in Ann Arbor, shows that the pattern of tooth eruption in early hominids, or human-like animals, is more like that of apes than people.
In an update on a report in NATURE last year, Smith discussed tooth development in 15 very early hominid juvenile jaws compared with dental development in living human beings and apes. 2 robust australopithecine species, members of a group that split from the human lineage and ultimately ended up being extinct, share an unique tooth eruption pattern “that is only ostensibly human-like,’ says Smith. “The pattern appears like neither apes nor human beings.’ Smith adds that Australopithecus afarensis, thought by many private investigators to be the earliest understood hominid, has an ape-like eruption sequence, as do A. africanus, Homo habilis and H. erectus, all extensively thought about to be in the human lineage.
Smith’s work, suggesting a relatively brief maturation period in very early hominids, is in agreement with a current research study of the timing of very early hominid tooth development by Timothy G. Bromage and C. Christopher Dean of College University in London, England (SN: 10/26/85, p. 260). They made use of an electron scanning microscope to count ridges on the enamel surface area that, according to research studies of modern-day people and various other creatures, type at the rate of about one weekly. Australopithecine and early Homo adolescent teeth displayed quick, ape-like development.
The two lines of dental proof suggest, states Smith, that prolonged care of gradually developing babies and cultural arrangements to deal with this necessity did not emerge up until relatively late in human advancement.
The information likewise show, notes Smith, that tooth development in modern humans and apes under three years of age “is not nearly as different as we thought it was. Clear distinctions just arise at later ages.’.