for National Geographic News
Bucking conventional wisdom, a new study says early members of our species, Homo sapiens, may have known what it was like to be a kid.
A long childhood is considered one of things that separate so-called modern humans from the first Homo sapiens and older human species, such as Homo erectus.
Now a study of a 160,000-year-old early Homo sapiens child found in North Africa may change how early—and where—we think modern humans arose.
A Study With Teeth
European researchers used x-ray imaging to study the growth patterns of teeth in the juvenile fossil found in Morocco. Similar to tree rings, the patterns are a record of aging.
What they revealed is that this fossil is the earliest known human with a long childhood, according to Tanya Smith, an anthropologist at the Max Planck Institute for Evolutionary Anthropology in Germany.
In the teeth the scientists found signs of modern-human development patterns—that is, relatively long periods of slow development and growth. A prolonged childhood is seen as necessary for the type of learning that leads to culture and complex society.
The juvenile fossil "showed an equivalent degree of tooth development to living [modern] human children at the same age," the report authors write.
According to the researchers, the study challenges theories about when and where humans acquired modern bodies and behaviors.
The findings also may help prove that "modern biological, behavioral, and cultural characteristics" were relative latecomers in the past six million years of human evolution.
(Related: "Adolescence Came Late in Human Evolution, Study Shows" [December 5, 2001].)
"These findings are in contrast to studies that suggest that earlier fossil hominins [humans and our ancestral species] possessed short growth periods, which were more similar to chimpanzees than to living humans," the study authors write in this week's issue of the journal Proceedings of the National Academy of Sciences.
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