Childhood's long history.You're lucky. Compared to other animals, you get to be a kid for a long time before you have to strike off on your own. Recent studies suggest that people have been enjoying long childhoods for many thousands of years. Some of this research has focused on several human teeth found in Morocco in 1968. On the basis of earlier studies of the molecules in these teeth, scientists estimate that their owner lived 160,000 years ago. [ILLUSTRATION OMITTED] In more recent studies of the Moroccan fossil, scientists from the Max Planck Institute for Evolutionary Anthropology The Max Planck Institute for Evolutionary Anthropology is a research institute for evolutionary anthropology based in Leipzig, Germany founded in 1997. It is part of the Max Planck Institute network. The Institute currently employs three-hundred and thirty-four people. in Leipzig, Germany, looked at a molar molar /mo·lar/ (mo´lar) 1. pertaining to a mole of a substance. 2. a measure of the concentration of a solute, expressed as the number of moles of solute per liter of solution. Symbol M, , or mol/L. (back tooth Noun 1. back tooth - a tooth situated at the back of the mouth posterior tooth - hard bonelike structures in the jaws of vertebrates; used for biting and chewing or for attack and defense ), a front tooth that was just starting to grow, and a canine (sharp, pointed side tooth) that hadn't yet broken through the gums. The researchers used a new X-ray technique to study these teeth and the hard substance called enamel that covers them. As kids grow, new layers of enamel form on their teeth every 7 to 9 days. Growing teeth also develop growth rings that are similar to the growth rings in tree trunks. By counting layers and rings in fossil teeth, scientists can tell how old the teeth--and the child who owned them--were. Using the new X-ray technique, the German scientists could count the layers and examine growth rings without damaging the teeth. In the past, scientists had to cut open teeth to count enamel layers enamel layer n. See ameloblastic layer. and rings. Results showed that the teeth belonged to a child who was 7 years, 10 months, old when he or she died. The fossil teeth looked just like the teeth of a modern 7-year-old. That suggests that kids who lived 160,000 years ago grew at about the same rate as modern kids do. "The [new] study pushes back clear evidence for humanlike growth to 160,000 years ago," remarks anthropologist B. Holly Smith of the University of Michigan (body, education) University of Michigan - A large cosmopolitan university in the Midwest USA. Over 50000 students are enrolled at the University of Michigan's three campuses. The students come from 50 states and over 100 foreign countries. in Ann Arbor Ann Arbor, city (1990 pop. 109,592), seat of Washtenaw co., S Mich., on the Huron River; inc. 1851. It is a research and educational center, with a large number of government and industrial research and development firms, many in high-technology fields such as . In another study, a different group of scientists used a similar X-ray technique to look at the molars of Neandertals who lived 127,000 years ago. These teeth also appeared to grow like ours do. Next, scientists want to use the new X-ray method to analyze even older tooth fossils. Recent evidence suggests that childhoods started to get longer around 1.6 million years ago in an ancestral human species called Homo erectus Homo erectus (hō`mō ērĕk`təs), extinct hominid living between 1.6 million and 250,000 years ago. Homo erectus is thought to have evolved in Africa from H. habilis, the first member of the genus Homo. . Our species, Homo sapiens Homo sapiens (Latin; “wise man”) Species to which all modern human beings belong. The oldest known fossil remains date to c. 120,000 years ago—or much earlier (c. , didn't exist until about 200,000 years ago. Childhood has a long history. Enjoy yours while you can! -- E. Sohn |
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