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Unformatted text preview: own children reach age 15 and reproduce.
For our purposes, then, any archaic individual judged to be
30 years old or more qualified as an older adult—one old enough
to have become a grandparent. But the beauty of the OY ratio
approach is that regardless of whether maturation occurred at
10, 15 or 20 years, the number of older and younger individuals
in a sample would be unaffected because the start of older adulthood would change accordingly. And because we were only
looking to place the fossils in these two broad categories, we
could include large numbers of smaller fossil samples in our
analysis without worrying about uncertainties in absolute ages.
We calculated the OY ratios for four large aggregates of fossil samples totaling 768 individuals spanning a period of three
million years. One aggregate comprised later australopithecines—those primitive relatives of “Lucy,” who lived in East Africa and South Africa from three million to 1.5 million years
ago. Another aggregate consisted of early members of our genus, Homo, from around the globe...
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This note was uploaded on 02/20/2013 for the course ANTH 101 taught by Professor Roseman during the Spring '12 term at University of Illinois, Urbana Champaign.
- Spring '12