The man of two million years ago, "homo erectus" skipped this problematic stage and passed into adulthood within 12 years; The intermediate stage appeared only half a million years ago; The reason: the brain was still small like a monkey
By: Walla system! 6/12/2001
Prehistoric man's mother, it turns out, had far fewer problems because, according to new research, he skipped the problematic period of puberty. The magazine "Nature" publishes that scientists believe that the ancient man "Homo erectus" developed like a monkey and thus skipped from childhood straight to adulthood without the intermediate stages.
Only in the more "advanced models" of early man did puberty appear to allow man to go through a longer learning process. Homo erectus was common in Africa about two million years ago and was characterized by an appearance approaching a human because of its shorter hands (as opposed to the long ape hands). The new study, based on fossilized teeth found, determined that Homo erectus did not have a graded puberty period. With the help of the teeth, it is possible to accurately determine what developmental stage a person is in in his life. By a thorough examination of the teeth, it is possible to determine how long it took for the tooth to grow using inner rings (similar to a tree). The findings showed that Homo erectus passed from childhood to adulthood after only 12 years, while it takes 20 years for modern man.
The new study reveals that the long intermediate stage of puberty appeared in humans only about half a million years ago. The reason Homo erectus did not pass the intermediate stage was his much smaller brain than that of modern man.
Puberty, a million and a half years ago
20/12/2001
Compared to chimpanzees and gorillas, humans take a long time to reach adulthood.
Compared to chimpanzees and gorillas, humans take a long time to reach adulthood. New research suggests that the ancestors of modern humans adopted this slow schedule only at a relatively late stage of evolution: one and a half million years ago, Homo erectus, one of the ancestors of humans, still reached adulthood in a relatively short time.
Chimpanzees and gorillas reach maturity at the age of 12-11. In humans, on the other hand, this happens at the age of 18 to 20. Previous studies have found that the distant ancestors of man matured quickly, but it is not clear when the more recent ancestors of man began to adopt the slow pace of development.
To examine this, researchers use dental fossils: tiny marks on the teeth serve researchers like tree rings: they allow them to deduce what the rate of formation of the tooth enamel was, and hence what the rate of maturation was.
Alan Walker, a professor of anthropology and biology at Penn State University, said that the accepted hypothesis among researchers was that Homo erectus reached maturity at a late age because its skeleton resembled that of modern humans. However, in a study published on December 6 in the journal Nature, Walker and his colleagues report that this hypothesis is incorrect.
Walker and his colleagues studied fossil teeth of Australopithecus, a human ancestor that lived 5 million to 2 million years ago; of Homo erectus, who lived about a million and a half years ago; And of Neanderthal man, who lived 120 thousand years ago. The research showed that the rate of development of Homo erectus was fast, and that only in Neanderthal man the rate resembles that of modern man.
That is, the change in the rate of development occurred at some time between Homo erectus and Neanderthal man - a conclusion that, while consistent with previous studies, narrows the range of years in which the change occurred.
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