Scientists at Harvard University say our characteristically slow development and long childhood are recent and unique to our species, and may have provided an evolutionary boost past earlier humans like Neanderthals, ScienceDaily.com reported.
The findings are based on sophisticated new analysis of teeth from 11 Neanderthal and early human fossils, researchers say.
"Teeth are remarkable time recorders, capturing each day of growth much like rings in trees reveal yearly progress," Tanya M. Smith, assistant professor of human evolutionary biology, says.
Smith and her colleagues found that young Neanderthals' teeth growth was significantly faster than in our own species, indicating that the elongation of human childhood has been a relatively recent development.
Other primates have shorter gestation, faster childhood maturation, younger age at first reproduction and a shorter overall lifespan compared to even early humans, the researchers say.
The findings add to a growing body of evidence that subtle developmental differences existed between our Neanderthal cousins and us.
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