TY - JOUR
T1 - Variation and diversity in Homo erectus
T2 - a 3D geometric morphometric analysis of the temporal bone
AU - Terhune, Claire E.
AU - Kimbel, William
AU - Lockwood, Charles A.
N1 - Funding Information:
For access to extant and fossil collections we thank the following individuals and institutions: Bruce Latimer, Yohannes Haile-Selassie, and Lyman Jellema, Cleveland Museum of Natural History (Cleveland, OH); Ian Tattersall, Ken Mowbray, and Gary Sawyer, American Museum of Natural History (New York, NY); Diane Hawkey, Arizona State University (Tempe, AZ); Wim van Neer, Royal Museum of Central Africa (Tervuren, Belgium); Richard Thorington and Linda Gordon, National Museum of Natural History (Washington, DC); David Pilbeam, Peabody Museum (Harvard University, Cambridge, MA); John Harrison, Powell-Cotton Museum (Birchington, Kent, UK). We also thank Gary Schwartz, Mark Spencer, Will Harcourt-Smith, Susan Antón, and three anonymous reviewers who provided technical expertise, constructive criticism, and helpful comments on prior drafts of this manuscript. This work was supported by US National Science Foundation grant BCS-9982022, a faculty grant-in-aid from Arizona State University, a Graduate Research Grant from the Arizona State University Department of Anthropology, and a Collections Study Grant from the American Museum of Natural History.
PY - 2007/7
Y1 - 2007/7
N2 - Although the level of taxonomic diversity within the fossil hominin species Homo erectus (sensu lato) is continually debated, there have been relatively few studies aiming to quantify the morphology of this species. Instead, most researchers have relied on qualitative descriptions or the evaluation of nonmetric characters, which in many cases display continuous variation. Also, only a few studies have used quantitative data to formally test hypotheses regarding the taxonomic composition of the "erectus" hypodigm. Despite these previous analyses, however, and perhaps in part due to these varied approaches for assessing variation within specimens typically referred to H. erectus (sensu lato) and the general lack of rigorous statistical testing of how variation within this taxon is partitioned, there is currently little consensus regarding whether this group is a single species, or whether it should instead be split into separate temporal or geographically delimited taxa. In order to evaluate possible explanations for variation within H. erectus, we tested the general hypothesis that variation within the temporal bone morphology of H. erectus is consistent with that of a single species, using great apes and humans as comparative taxa. Eighteen three-dimensional (3D) landmarks of the temporal bone were digitized on a total of 520 extant and fossil hominid crania. Landmarks were registered by Generalized Procrustes Analysis, and Procrustes distances were calculated for comparisons of individuals within and between the extant taxa. Distances between fossil specimens and between a priori groupings of fossils were then compared to the distances calculated within the extant taxa to assess the variation within the H. erectus sample relative to that of known species, subspecies, and populations. Results of these analyses indicate that shape variation within the entire H. erectus sample is generally higher than extant hominid intraspecific variation, and putative H. ergaster specimens are significantly different from other specimens in H. erectus (sensu lato). However, shape distances within geographical groups of H. erectus are also high, and OH 9 and Dmanisi 2280 are morphologically distinct from the Koobi Fora specimens that are sometimes classified as H. ergaster. These findings suggest that, although H. erectus may be composed of multiple species, the differentiation is complex, and specimens cannot easily be grouped geographically or chronologically. Consequently, more complicated scenarios seeking to explain the observed variation within H. erectus must be considered.
AB - Although the level of taxonomic diversity within the fossil hominin species Homo erectus (sensu lato) is continually debated, there have been relatively few studies aiming to quantify the morphology of this species. Instead, most researchers have relied on qualitative descriptions or the evaluation of nonmetric characters, which in many cases display continuous variation. Also, only a few studies have used quantitative data to formally test hypotheses regarding the taxonomic composition of the "erectus" hypodigm. Despite these previous analyses, however, and perhaps in part due to these varied approaches for assessing variation within specimens typically referred to H. erectus (sensu lato) and the general lack of rigorous statistical testing of how variation within this taxon is partitioned, there is currently little consensus regarding whether this group is a single species, or whether it should instead be split into separate temporal or geographically delimited taxa. In order to evaluate possible explanations for variation within H. erectus, we tested the general hypothesis that variation within the temporal bone morphology of H. erectus is consistent with that of a single species, using great apes and humans as comparative taxa. Eighteen three-dimensional (3D) landmarks of the temporal bone were digitized on a total of 520 extant and fossil hominid crania. Landmarks were registered by Generalized Procrustes Analysis, and Procrustes distances were calculated for comparisons of individuals within and between the extant taxa. Distances between fossil specimens and between a priori groupings of fossils were then compared to the distances calculated within the extant taxa to assess the variation within the H. erectus sample relative to that of known species, subspecies, and populations. Results of these analyses indicate that shape variation within the entire H. erectus sample is generally higher than extant hominid intraspecific variation, and putative H. ergaster specimens are significantly different from other specimens in H. erectus (sensu lato). However, shape distances within geographical groups of H. erectus are also high, and OH 9 and Dmanisi 2280 are morphologically distinct from the Koobi Fora specimens that are sometimes classified as H. ergaster. These findings suggest that, although H. erectus may be composed of multiple species, the differentiation is complex, and specimens cannot easily be grouped geographically or chronologically. Consequently, more complicated scenarios seeking to explain the observed variation within H. erectus must be considered.
KW - Hominids
KW - Hominins
KW - Homo ergaster
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U2 - 10.1016/j.jhevol.2007.01.006
DO - 10.1016/j.jhevol.2007.01.006
M3 - Article
C2 - 17512034
AN - SCOPUS:34249715683
SN - 0047-2484
VL - 53
SP - 41
EP - 60
JO - Journal of human evolution
JF - Journal of human evolution
IS - 1
ER -