Human Interaction with North American Pleistocene Proboscideans

在国家科学基金会的支持下， 一系列猛犸象和乳齿象的牙本质叠层 他们生活在CA之间。一万两千年前在北方 美国参考费舍尔博士先前的研究表明， 这些物种的颊齿表现出牙本质层压， 记录个人生活史的细节。连续顺序 分层表示年、双周和日周期， 增生的牙本质对这些模式的分析产生了以下数据 季节性死亡率、年龄、性别、生长率、性生活年龄 成熟和产犊。这些因素是敏感的性质 以及动物所处的生态压力程度 并表现出可预测的反应模式， 改变营养状况和/或捕食压力。与这些 费舍尔博士将量化这些生命史轨迹， 两个物种在灭绝之前他会比较 结果与数据从现存的大象从一系列的 环境.在此基础上，他将确定 导致了猛犸象和乳齿象的灭绝 更新世 人们早就知道，最后一个冰河时代的结束， 北美许多动物物种的灭绝。而 这一事实是无可争议的，原因尚待确定。而 一些科学家认为， 但另一些人指出，这些主要的预防措施似乎 与人类猎人聚集在北 相信过度捕猎导致了它们的灭亡。的 费舍尔博士将收集的数据允许，他相信， 区分这些可能的原因。 这项研究之所以重要，有几个原因。它将提供 洞察史前人类行为的古人类学家 和生计模式。它还将揭示 人类捕食、环境交换和 物种灭绝是当今一个重要的问题。

With National Science Foundation support Dr. Fisher will study tusk dentin laminations in a series of mammoths and mastodonts which lived between ca. 12,000 and 10,000 years ago in North America. Prior work by Dr. Fisher has shown that the tusks and cheek teeth of these species exhibit dentinal laminations that record details of individual life history. Successive orders of lamination represent annual, fortnightly and daily cycles in accreted dentin. Analyses of these patterns yield data on seasonal mortality, age, sex, growth rates, age at sexual maturity and calving. These factors are sensitive to the nature and degree of ecological stress to which the animal had been subjected and demonstrate predictable patterns of response to altered nutritional status and/or predation pressure. With such data Dr. Fisher will quantify these life history trails for the two species just before their time of extinction. He will compare the results with data from extant elephants from a range of environments. On this basis he will determine the factors which led to the extinction of mammoths and mastodonts at the end of the Pleistocene. It has long been known that the end of the last Ice Age saw the extinction of many species of animals in North America. While this fact is undisputed the cause has yet to be determined. While some scientists argue that environmental change alone is responsible, others note that these major extinctions seem to coincide with the appearance of human hunter gathers in North America and believe that overhunting led to their demise. The data Dr. Fisher will collect allows, he believes, for a distinction between these possible causes. This research is important for several reasons. It will provide paleoanthropologists with insight into prehistoric human behavior and subsistence patterns. It will also shed light on the relationships between human predation, environmental exchange and species extinction, a problem of major significance today.