A resampling approach and implications for estimating the phalangeal index from unassociated hand bones in fossil primates

Bibliographic Data

ID8311316
AuthorsVivek V Venkataraman (0000-0001-5016-4423, Department of Biological Sciences Class of 1978 Life Sciences Center, Dartmouth College Hanover NH 03755), C Rolian (0000-0002-7242-342X, University of Calgary), Adam D Gordon (0000-0002-1807-4644, Department of Anthropology University at Albany–SUNY Albany NY 12222), B A Patel (0000-0003-1844-1931, Department of Cell and Neurobiology Keck School of Medicine University of Southern California Los Angeles CA 90033, corresponding author)
Year2013
Volume151
Issue2
Pages280-289
Publication date2013-06-01
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueAmerican Journal of Physical Anthropology (JOURNAL)
Journal identifiersISSN: 0002-9483 • E-ISSN: 1096-8644
PublisherWiley (PUBLISHER • GB)
DOI10.1002/ajpa.22278
PMID23633100
OpenAlexW1826438709
LanguageEN
Citations received4
References cited40

Primate fossil assemblages often have metacarpals and phalanges from which functional/behavioral interpretations may be inferred. For example, intrinsic hand proportions can indicate hand function and substrate use. But, estimates of intrinsic hand proportions from unassociated hand elements can be imperfect due to digit misattribution. Although isolated metacarpals can be identified to a specific digit, phalanges are difficult to assign to a specific ray. We used a resampling approach to evaluate how estimates of intrinsic hand proportions are affected by such uncertainty. First, the phalangeal index—intermediate phalanx length plus proximal phalanx length divided by metacarpal length—for the third digit was calculated for associated specimens of terrestrial, semiterrestrial, and arboreal taxa. We then used resampling procedures to generate distributions of “composite digits” based on resampled ratios in which phalanges from the second, fourth, and fifth rays, and from different individuals, were chosen randomly. Results confirm that the phalangeal index for associated third digits significantly discriminates groups. We also found that resampled ratios had significantly lower means, indicating that using composite digits is prone to systematic underestimation. Resampled ratios also generated distributions with greater variance around the means that obscured distinctions between groups, although significant differences between the most arboreal and terrestrial taxa are maintained. We conclude that using unassociated phalanges to calculate a phalangeal index is prone to sampling bias. Nevertheless, a resampling approach has the potential to inform estimates of hand proportions for fossil taxa, provided that the comparative sample is constrained to mimic the fossil composition. Am J Phys Anthropol 151:280–289, 2013. © 2013 Wiley Periodicals, Inc

Arboreal locomotion · Arithmetic · Biology · Evolutionary biology · Numerical digit · Phalanx · Resampling · Statistics · Anatomy · Animal Vocal Communication and Behavior · Ecology · Evolution and Paleontology Studies · Mathematics · Paleontology · Primate Behavior and Ecology

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