{"title":"Relative limb strength and locomotion in Homo habilis.","authors":"Christopher Ruff","doi":"10.1002/ajpa.20907","DOIUrl":null,"url":null,"abstract":"<p><p>The Homo habilis OH 62 partial skeleton has played an important, although controversial role in interpretations of early Homo locomotor behavior. Past interpretive problems stemmed from uncertain bone length estimates and comparisons using external bone breadth proportions, which do not clearly distinguish between modern humans and apes. Here, true cross-sectional bone strength measurements of the OH 62 femur and humerus are compared with those of modern humans and chimpanzees, as well as two early H. erectus specimens-KNM-WT 15000 and KNM-ER 1808. The comparative sections include two locations in the femur and two in the humerus in order to encompass the range of possible section positions in the OH 62 specimens. For each combination of section locations, femoral to humeral strength proportions of OH 62 fall below the 95% confidence interval of modern humans, and for most comparisons, within the 95% confidence interval of chimpanzees. In contrast, the two H. erectus specimens both fall within or even above the modern human distributions. This indicates that load distribution between the limbs, and by implication, locomotor behavior, was significantly different in H. habilis from that of H. erectus and modern humans. When considered with other postcranial evidence, the most likely interpretation is that H. habilis, although bipedal when terrestrial, still engaged in frequent arboreal behavior, while H. erectus was a completely committed terrestrial biped. This adds to the evidence that H. habilis (sensu stricto) and H. erectus represent ecologically distinct, parallel lineages during the early Pleistocene.</p>","PeriodicalId":7587,"journal":{"name":"American journal of physical anthropology","volume":null,"pages":null},"PeriodicalIF":2.6000,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/ajpa.20907","citationCount":"132","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"American journal of physical anthropology","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1002/ajpa.20907","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ANTHROPOLOGY","Score":null,"Total":0}
引用次数: 132
Abstract
The Homo habilis OH 62 partial skeleton has played an important, although controversial role in interpretations of early Homo locomotor behavior. Past interpretive problems stemmed from uncertain bone length estimates and comparisons using external bone breadth proportions, which do not clearly distinguish between modern humans and apes. Here, true cross-sectional bone strength measurements of the OH 62 femur and humerus are compared with those of modern humans and chimpanzees, as well as two early H. erectus specimens-KNM-WT 15000 and KNM-ER 1808. The comparative sections include two locations in the femur and two in the humerus in order to encompass the range of possible section positions in the OH 62 specimens. For each combination of section locations, femoral to humeral strength proportions of OH 62 fall below the 95% confidence interval of modern humans, and for most comparisons, within the 95% confidence interval of chimpanzees. In contrast, the two H. erectus specimens both fall within or even above the modern human distributions. This indicates that load distribution between the limbs, and by implication, locomotor behavior, was significantly different in H. habilis from that of H. erectus and modern humans. When considered with other postcranial evidence, the most likely interpretation is that H. habilis, although bipedal when terrestrial, still engaged in frequent arboreal behavior, while H. erectus was a completely committed terrestrial biped. This adds to the evidence that H. habilis (sensu stricto) and H. erectus represent ecologically distinct, parallel lineages during the early Pleistocene.
期刊介绍:
The American Journal of Physical Anthropology (AJPA) is the official journal of the American Association of Physical Anthropologists. The Journal is published monthly in three quarterly volumes. In addition, two supplements appear on an annual basis, the Yearbook of Physical Anthropology, which publishes major review articles, and the Annual Meeting Issue, containing the Scientific Program of the Annual Meeting of the American Association of Physical Anthropologists and abstracts of posters and podium presentations. The Yearbook of Physical Anthropology has its own editor, appointed by the Association, and is handled independently of the AJPA. As measured by impact factor, the AJPA is among the top journals listed in the anthropology category by the Social Science Citation Index. The reputation of the AJPA as the leading publication in physical anthropology is built on its century-long record of publishing high quality scientific articles in a wide range of topics.