Are OY ratios invariant ? A reply to Hawkes and O ’ Connell ( 2005 )
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چکیده
Human longevity has been difficult to study using the fossil record due to constraints on paleodemography caused by a number of variables. These constraints include: small sample sizes; under-representation of age classes, particularly juveniles; and difficulties assessing adult age at death with high precision. Life span and other population statistics that are necessary for demography are dependent on information about juveniles and precise ages of old adults, information not wellrepresented in the fossil record. We recently published a novel way to deal with the question of longevity using the OY ratiodthe ratio of older to younger adults in fossil samples (Caspari and Lee, 2004). Instead of estimating life span, this approach focuses on the number of adults that live to be old. While change in the OY ratio is not a direct
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تاریخ انتشار 2005