1
|
Kralick AE, O'Connell CA, Bastian ML, Hoke MK, Zemel BS, Schurr TG, Tocheri MW. Beyond Dimorphism: Body Size Variation Among Adult Orangutans Is Not Dichotomous by Sex. Integr Comp Biol 2023; 63:907-921. [PMID: 37061788 PMCID: PMC10563650 DOI: 10.1093/icb/icad015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/23/2023] [Accepted: 04/04/2023] [Indexed: 04/17/2023] Open
Abstract
Among extant great apes, orangutans are considered the most sexually dimorphic in body size. However, the expression of sexual dimorphism in orangutans is more complex than simply males being larger than females. At sexual maturity, some male orangutans develop cheek pads (flanges), while other males remain unflanged even after becoming reproductively capable. Sometimes flange development is delayed in otherwise sexually mature males for a few years. In other cases, flange development is delayed for many years or decades, with some males even spending their entire lifespan as unflanged adults. Thus, unflanged males of various chronological ages can be mistakenly identified as "subadults." Unflanged adult males are typically described as "female-sized," but this may simply reflect the fact that unflanged male body size has only ever been measured in peri-pubescent individuals. In this study, we measured the skeletons of 111 wild adult orangutans (Pongo spp.), including 20 unflanged males, 45 flanged males, and 46 females, resulting in the largest skeletal sample of unflanged males yet studied. We assessed long bone lengths (as a proxy for stature) for all 111 individuals and recorded weights-at-death, femoral head diameters, bi-iliac breadths, and long bone cross-sectional areas (CSA) (as proxies for mass) for 27 of these individuals, including seven flanged males, three adult confirmed-unflanged males, and three young adult likely-unflanged males. ANOVA and Kruskal-Wallis tests with Tukey and Dunn post-hoc pairwise comparisons, respectively, showed that body sizes for young adult unflanged males are similar to those of the adult females in the sample (all P ≥ 0.09 except bi-iliac breadth), whereas body sizes for adult unflanged males ranged between those of adult flanged males and adult females for several measurements (all P < 0.001). Thus, sexually mature male orangutans exhibit body sizes that range from the female end of the spectrum to the flanged male end of the spectrum. These results exemplify that the term "sexual dimorphism" fails to capture the full range of variation in adult orangutan body size. By including adult unflanged males in analyses of body size and other aspects of morphology, not as aberrations but as an expected part of orangutan variation, we may begin to shift the way that we think about features typically considered dichotomous according to biological sex.
Collapse
Affiliation(s)
- Alexandra E Kralick
- Department of Anthropology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Caitlin A O'Connell
- Department of Anthropology, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Anthropology, Rutgers, the State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Meredith L Bastian
- Proceedings of the National Academy of Sciences, Washington, DC 20001, USA
| | - Morgan K Hoke
- Department of Anthropology & Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Babette S Zemel
- Division of Gastroenterology, Hepatology and Nutrition, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
- , Department of Pediatrics, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Theodore G Schurr
- Department of Anthropology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Matthew W Tocheri
- Department of Anthropology, Lakehead University, Thunder Bay, ON P7B 5E1, Canada
- Human Origins Program, Department of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013, USA
- Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage, University of Wollongong, Wollongong NSW 2522, Australia
| |
Collapse
|
2
|
Pampush JD, Fuselier EJ, Yapuncich GS. Using BayesModelS to provide Bayesian- and phylogenetically-informed primate body mass predictions. J Hum Evol 2021; 161:103077. [PMID: 34688978 DOI: 10.1016/j.jhevol.2021.103077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 09/01/2021] [Accepted: 09/01/2021] [Indexed: 10/20/2022]
Abstract
An accurate prediction of the body mass of an extinct species can greatly inform the reconstruction of that species' ecology. Therefore, paleontologists frequently predict the body mass of extinct taxa from fossilized materials, particularly dental dimensions. Body mass prediction has traditionally been performed in a frequentist statistical framework, and accounting for phylogenetic relationships while calibrating prediction models has only recently become more commonplace. In this article, we apply BayesModelS-a phylogenetically informed Bayesian prediction method-to predict body mass in a sample of 49 euarchontan species (24 strepsirrhines, 20 platyrrhines, 3 tarsiids, 1 dermopteran, and 1 scandentian) and compare this approach's body mass prediction accuracy with other commonly used techniques, namely ordinary least squares, phylogenetic generalized least squares, and phylogenetic independent contrasts (PICs). When predicting the body masses of extant euarchontans from dental and postcranial variables, BayesModelS and PICs have substantially higher predictive accuracy than ordinary least squares and phylogenetic generalized least squares. The improved performances of BayesModelS and PIC are most evident for dentally derived body mass proxies or when body mass proxies have high degrees of phylogenetic covariance. Predicted values generated by BayesModelS and PIC methods also show less variance across body mass proxies when applied to the Eocene adapiform Notharctus tenebrosus. These more explicitly phylogenetically based methods should prove useful for predicting body mass in a paleontological context, and we provide executive scripts for both BayesModelS and PIC to increase ease of application.
Collapse
Affiliation(s)
- James D Pampush
- Department of Exercise Science, High Point University, High Point, NC 27260, USA; Department of Physician Assistant Studies, High Point University, High Point, NC 27260, USA.
| | - Edward J Fuselier
- Department of Mathematical Sciences, High Point University, High Point, NC 27260, USA
| | - Gabriel S Yapuncich
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA; Medical Education Administration, Duke University School of Medicine, Durham, NC 27710, USA
| |
Collapse
|
3
|
Ruff CB, Wunderlich RE, Hatala KG, Tuttle RH, Hilton CE, D'Août K, Webb DM, Hallgrímsson B, Musiba C, Baksh M. Body mass estimation from footprint size in hominins. J Hum Evol 2021; 156:102997. [PMID: 33993031 DOI: 10.1016/j.jhevol.2021.102997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 03/23/2021] [Accepted: 03/28/2021] [Indexed: 10/21/2022]
Abstract
Although many studies relating stature to foot length have been carried out, the relationship between foot size and body mass remains poorly understood. Here we investigate this relationship in 193 adult and 50 juvenile habitually unshod/minimally shod individuals from five different populations-Machiguenga, Daasanach, Pumé, Hadzabe, and Samoans-varying greatly in body size and shape. Body mass is highly correlated with foot size, and can be predicted from foot area (maximum length × breadth) in the combined sample with an average error of about 10%. However, comparisons among populations indicate that body shape, as represented by the body mass index (BMI), has a significant effect on foot size proportions, with higher BMI samples exhibiting relatively smaller feet. Thus, we also derive equations for estimating body mass from both foot size and BMI, with BMI in footprint samples taken as an average value for a taxon or population, estimated independently from skeletal remains. Techniques are also developed for estimating body mass in juveniles, who have relatively larger feet than adults, and for converting between foot and footprint size. Sample applications are given for five Pliocene through Holocene hominin footprint samples from Laetoli (Australopithecus afarensis), Ileret (probable Homo erectus), Happisburgh (possible Homo antecessor), Le Rozel (archaic Homo sapiens), and Barcin Höyük (H. sapiens). Body mass estimates for Homo footprint samples appear reasonable when compared to skeletal estimates for related samples. However, estimates for the Laetoli footprint sample using the new formulae appear to be too high when compared to skeletal estimates for A. afarensis. Based on the proportions of A.L. 288-1, this is apparently a result of relatively large feet in this taxon. A different method using a ratio between body mass and foot area in A.L. 288-1 provides estimates more concordant with skeletal estimates and should be used for A. afarensis.
Collapse
Affiliation(s)
- Christopher B Ruff
- Center for Functional Anatomy and Evolution, Johns Hopkins University School of Medicine, 1800 E. Monument St., Baltimore, MD, 21111, USA.
| | - Roshna E Wunderlich
- Department of Biology, James Madison University, MSC 7801, Harrisonburg, VA, 22807, USA
| | - Kevin G Hatala
- Department of Biology, Chatham University, Buhl Hall, Woodland Rd., Pittsburgh, PA, 15232, USA
| | - Russell H Tuttle
- Department of Anthropology, University of Chicago, 1126 East 59th Street, Chicago, IL, 60637, USA
| | - Charles E Hilton
- Department of Anthropology, University of North Carolina, 301 Alumni Bldg., Chapel Hill, NC, 27599-3115, USA
| | - Kristiaan D'Août
- Department of Musculoskeletal and Ageing Science, Institute of Life Course and Medical Sciences, University of Liverpool, 6 West Derby Street, Liverpool, L7 8TX, UK
| | - David M Webb
- Department of Anthropology and Sociology, Kutztown University, Kutztown, PA, 19530, USA
| | - Benedikt Hallgrímsson
- Department of Cell Biology & Anatomy, Alberta Children's Hospital Research Institute, McCaig Institute for Bone and Joint Health, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. NW, Calgary, Alberta, T2N 4N1, Canada
| | - Charles Musiba
- Department of Anthropology, University of Colorado Denver, NC Building, Suite 4002, 1200 Larimer Street, Denver, CO, 80217, USA
| | | |
Collapse
|
4
|
Yapuncich GS, Bowie A, Belais R, Churchill SE, Walker CS. Predicting body mass of bonobos (Pan paniscus) with human-based morphometric equations. Am J Primatol 2020; 82:e23088. [PMID: 31961002 DOI: 10.1002/ajp.23088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 11/06/2019] [Accepted: 12/15/2019] [Indexed: 01/31/2023]
Abstract
A primate's body mass covaries with numerous ecological, physiological, and behavioral characteristics. This versatility and potential to provide insight into an animal's life has made body mass prediction a frequent and important objective in paleoanthropology. In hominin paleontology, the most commonly employed body mass prediction equations (BMPEs) are "mechanical" and "morphometric": uni- or multivariate linear regressions incorporating dimensions of load-bearing skeletal elements and stature and living bi-iliac breadth as predictor variables, respectively. The precision and accuracy of BMPEs are contingent on multiple factors, however, one of the most notable and pervasive potential sources of error is extrapolation beyond the limits of the reference sample. In this study, we use a test sample requiring extrapolation-56 bonobos (Pan paniscus) from the Lola ya Bonobo sanctuary in Kinshasa, Democratic Republic of the Congo-to evaluate the predictive accuracy of human-based morphometric BMPEs. We first assess systemic differences in stature and bi-iliac breadth between humans and bonobos. Due to significant differences in the scaling relationships of body mass and stature between bonobos and humans, we use panel regression to generate a novel BMPE based on living bi-iliac breadth. We then compare the predictive accuracy of two previously published morphometric equations with the novel equation and find that the novel equation predicts bonobo body mass most accurately overall (41 of 56 bonobos predicted within 20% of their observed body mass). The novel BMPE is particularly accurate between 25 and 45 kg. Given differences in limb proportions, pelvic morphology, and body tissue composition between the human reference and bonobo test samples, we find these results promising and evaluate the novel BMPE's potential application to fossil hominins.
Collapse
Affiliation(s)
- Gabriel S Yapuncich
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina.,Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Aleah Bowie
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina
| | | | - Steven E Churchill
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina.,Evolutionary Studies Institute, University of the Witwatersrand, Wits, South Africa
| | - Christopher S Walker
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina.,Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina.,Evolutionary Studies Institute, University of the Witwatersrand, Wits, South Africa
| |
Collapse
|
5
|
Evaluating morphometric body mass prediction equations with a juvenile human test sample: accuracy and applicability to small-bodied hominins. J Hum Evol 2018; 115:65-77. [DOI: 10.1016/j.jhevol.2017.03.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 03/13/2017] [Accepted: 03/14/2017] [Indexed: 11/18/2022]
|
6
|
Yapuncich GS, Churchill SE, Cameron N, Walker CS. Morphometric panel regression equations for predicting body mass in immature humans. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 166:179-195. [DOI: 10.1002/ajpa.23422] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 12/20/2017] [Accepted: 01/13/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Gabriel S. Yapuncich
- Department of Molecular Biomedical Sciences, College of Veterinary MedicineNorth Carolina State UniversityNorth Carolina 27607
- Department of Evolutionary AnthropologyDuke UniversityDurham North Carolina 27708
| | - Steven E. Churchill
- Department of Evolutionary AnthropologyDuke UniversityDurham North Carolina 27708
- Evolutionary Studies InstituteUniversity of the WitwatersrandWits 2050 South Africa
| | - Noël Cameron
- Evolutionary Studies InstituteUniversity of the WitwatersrandWits 2050 South Africa
- School of Sport, Exercise and Health SciencesLoughborough UniversityLoughborough, LE11 3TU United Kingdom
| | - Christopher S. Walker
- Department of Molecular Biomedical Sciences, College of Veterinary MedicineNorth Carolina State UniversityNorth Carolina 27607
- Department of Evolutionary AnthropologyDuke UniversityDurham North Carolina 27708
- Evolutionary Studies InstituteUniversity of the WitwatersrandWits 2050 South Africa
| |
Collapse
|
7
|
Cardoso HFV, Vandergugten JM, Humphrey LT. Age estimation of immature human skeletal remains from the metaphyseal and epiphyseal widths of the long bones in the post-natal period. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2016; 162:19-35. [DOI: 10.1002/ajpa.23081] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 07/22/2016] [Accepted: 08/13/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Hugo F. V. Cardoso
- Department of Archaeology; Simon Fraser University; Burnaby British Columbia V5A 1S6 Canada
| | - John M. Vandergugten
- Department of Archaeology; Simon Fraser University; Burnaby British Columbia V5A 1S6 Canada
| | - Louise T. Humphrey
- Human Origins Group, Department of Palaeontology; The Natural History Museum; London SW7 5BD United Kingdom
| |
Collapse
|
8
|
Mays S. Estimation of stature in archaeological human skeletal remains from Britain. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2016; 161:646-655. [DOI: 10.1002/ajpa.23068] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/20/2016] [Accepted: 08/01/2016] [Indexed: 11/08/2022]
Affiliation(s)
- S. Mays
- Research Department, Historic EnglandFort CumberlandEastney PortsmouthPO4 9LD
| |
Collapse
|
9
|
Niskanen M, Maijanen H, McCarthy D, Junno JA. Application of the anatomical method to estimate the maximum adult stature and the age-at-death stature. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2013; 152:96-106. [PMID: 23907777 DOI: 10.1002/ajpa.22332] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 06/10/2013] [Indexed: 11/08/2022]
Abstract
This study focuses on the age adjustment of statures estimated with the anatomical method. The research material includes 127 individuals from the Terry Collection. The cadaveric stature (CSTA)-skeletal height (SKH) ratios indicate that stature loss with age commences before SKH reduction. Testing three equations to estimate CSTA at the age at death and CSTA corrected to maximum stature from SKH indicates that the age correction of stature should reflect the pattern of age-related stature loss to minimize estimation error. An equation that includes a continuous and linear age correction through the entire adult age range [Eq. (1)] results in curvilinear stature estimation error. This curvilinear stature estimation error can be largely avoided by applying a second linear equation [Eq. (2)] to only individuals older than 40 years. Our third equation [Eq. (3)], based on younger individuals who have not lost stature, can be used to estimate maximum stature. This equation can also be applied to individuals of unknown or highly uncertain age, because it provides reasonably accurate estimates until about 60/70 years at least for males.
Collapse
Affiliation(s)
- Markku Niskanen
- Department of Archaeology, University of Oulu, Oulu, 90014, Finland
| | | | | | | |
Collapse
|
10
|
Differences between Neandertal and modern human infant and child growth models. J Hum Evol 2012; 63:140-9. [DOI: 10.1016/j.jhevol.2012.04.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 04/26/2012] [Accepted: 04/26/2012] [Indexed: 11/18/2022]
|
11
|
Maijanen H. Testing Anatomical Methods for Stature Estimation on Individuals from the W. M. Bass Donated Skeletal Collection. J Forensic Sci 2009; 54:746-52. [DOI: 10.1111/j.1556-4029.2009.01053.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
12
|
Estimation of African apes’ body size from postcranial dimensions. Primates 2009; 50:211-20. [DOI: 10.1007/s10329-009-0131-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Accepted: 01/20/2009] [Indexed: 10/21/2022]
|
13
|
Breuer T, Robbins MM, Boesch C. Using photogrammetry and color scoring to assess sexual dimorphism in wild western gorillas (Gorilla gorilla). AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2007; 134:369-82. [PMID: 17657788 DOI: 10.1002/ajpa.20678] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Investigating sexual dimorphism is important for our understanding of its influence on reproductive strategies including male-male competition, mate choice, and sexual conflict. Measuring physical traits in wild animals can be logistically challenging and disruptive for the animals. Therefore body size and ornament variation in wild primates have rarely been quantified. Gorillas are amongst the most sexually dimorphic and dichromatic primates. Adult males (silverbacks) possess a prominent sagittal crest, a pad of fibrous and fatty tissue on top of the head, have red crest coloration, their saddle appears silver, and they possess a silverline along their stomach. Here we measure levels of sexual dimorphism and within-male variation of body length, head size, and sexual dichromatism in a population of wild western gorillas using photogrammetry. Digital photogrammetry is a useful and precise method to measure sexual dimorphism in physical traits yielding sexual dimorphism indices (ISD), similar to those derived from traditional measurements of skeletal remains. Silverbacks were on an average 1.23 times longer in body length than adult females. Sexual dimorphism of head size was highest in measures of crest size (max ISD: 60.4) compared with measures of facial height (max ISD: 24.7). The most sexually dimorphic head size measures also showed the highest within-sex variation. We found no clear sex differences in crest coloration but there was large sexual dichromatism with high within-male variation in saddle coloration and silverline size. Further studies should examine if these sexually dimorphic traits are honest signals of competitive ability and confer an advantage in reproductive success.
Collapse
Affiliation(s)
- Thomas Breuer
- Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103 Leipzig, Germany.
| | | | | |
Collapse
|
14
|
Ruff C. Body size prediction from juvenile skeletal remains. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2007; 133:698-716. [PMID: 17295297 DOI: 10.1002/ajpa.20568] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
There are currently no methods for predicting body mass from juvenile skeletal remains and only a very limited number for predicting stature. In this study, stature and body mass prediction equations are generated for each year from 1 to 17 years of age using a subset of the Denver Growth Study sample, followed longitudinally (n = 20 individuals, 340 observations). Radiographic measurements of femoral distal metaphyseal and head breadth are used to predict body mass and long bone lengths are used to predict stature. In addition, pelvic bi-iliac breadth and long bone lengths are used to predict body mass in older adolescents. Relative prediction errors are equal to or smaller than those associated with similar adult estimation formulae. Body proportions change continuously throughout growth, necessitating age-specific formulae. Adult formulae overestimate stature and body mass in younger juveniles, but work well in 17-year-olds from the sample, indicating that in terms of body proportions they are representative of the general population. To illustrate use of the techniques, they are applied to the juvenile Homo erectus (ergaster) KNM-WT 15000 skeleton. New body mass and stature estimates for this specimen are similar to previous estimates derived using other methods. Body mass estimates range from 50 to 53 kg, and stature was probably slightly under 157 cm, although a precise stature estimate is difficult to determine due to differences in linear body proportions between KNM-WT 15000 and the Denver reference sample.
Collapse
Affiliation(s)
- Christopher Ruff
- Center for Functional Anatomy and Evolution, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
15
|
Haeusler M, McHenry HM. Body proportions of Homo habilis reviewed. J Hum Evol 2004; 46:433-65. [PMID: 15066379 DOI: 10.1016/j.jhevol.2004.01.004] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2002] [Accepted: 01/21/2004] [Indexed: 11/25/2022]
Abstract
The ratio of fore- to hindlimb size plays an important role in our understanding of human evolution. Although Homo habilis was relatively modern craniodentally, its body proportions are commonly believed to have been more apelike than in the earlier Australopithecus afarensis. The evidence for this, however, rests, on two fragmentary skeletons, OH 62 and KNM-ER 3735. The upper limb of the better-preserved OH 62 from Olduvai Gorge is long and slender, but its hindlimb is represented mainly by the proximal portion of a thin femur of uncertain length. The present analysis shows that upper-to-lower limb shaft proportions of both OH 62 and AL 288-1 (A. afarensis) fall in the modern human range of variation, although OH 62 also falls inside that of chimpanzees due to their overlap in small individuals. Despite being more fragmentary, the larger-bodied KNM-ER 3735 lies outside the chimpanzee range and close to the human mean. Because the differences between any of the three individuals are compatible with the range of variation seen in extant hominoid groups, it is not legitimate to infer more primitive upper-to-lower limb shaft proportions for either H. habilis or A. afarensis. Femur length of OH 62 can only be estimated by comparison. Its closest match in size and morphology is with the gracile OH 34 specimen, which therefore provides a better analogue for the reconstruction of OH 62 than the stocky AL 288-1 femur that is traditionally used. OH 34's slender proportions are hardly due to abrasion, but match those of a modern human of that body-size, suggesting that the relative length of OH 62's leg may have been human-like. Brachial proportions, however, remained primitive. Long legs may imply long distance terrestrial travel. Perhaps this adaptation evolved early in the genus Homo, with H. habilis providing an early representative of this important change.
Collapse
Affiliation(s)
- Martin Haeusler
- Department of Anthropology, University of California, Davis, CA 95616, USA.
| | | |
Collapse
|
16
|
Abstract
Three methods of measuring stature from skeletal remains are reviewed: the reconstructed skeletal length, the correspondence of long bone length to stature and the regression of stature on long bone length. Each involves problems and difficulties. For the anthropologist, there is the additional problem of applying findings from extant taxa to extinct taxa with potentially different morphologies and limb proportions. Of the various studies involving regression of the stature the findings of Trotter and Gleser are judged the most robust and useful notwithstanding problems and limitations. The lumbar vertebrae are potentially important as stature predictors. Estimation of body mass from the skeleton is also beset with problems. Eight methods are reviewed: Hartwig-Scherer's taxon independent solution, four methods involving measurements from the weight-bearing appendicular skeleton, Ruff's method using the length of the reconstructed skeleton and an estimate of body breadth, estimates from the total skeletal mass and estimates from the body mass index when the stature is known approximately. Lumbar vertebrae provide reasonable estimates of both body mass and stature and thus by derivation the body mass index. At present both forensic scientists and anthropologists lack adequate data and methods to estimate body size and shape from hominin skeletons. A further large and well-designed study using magnetic resonance imaging is required.
Collapse
|
17
|
Ohman JC, Wood C, Wood B, Crompton RH, Günther MM, Yu L, Savage R, Wang W. Stature-at-death of KNM-WT 15000. ACTA ACUST UNITED AC 2002. [DOI: 10.1007/bf02436366] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
18
|
Hens SM, Konigsberg LW, Jungers WL. Estimating stature in fossil hominids: which regression model and reference sample to use? J Hum Evol 2000; 38:767-84. [PMID: 10835261 DOI: 10.1006/jhev.1999.0382] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
coResearchers have long appreciated the significant relationship between body size and an animal's overall adaptive strategy and life history. However, much more emphasis has been placed on interpreting body size than on the actual calculation of it. One measure of size that is especially important for human evolutionary studies is stature. Despite a long history of investigation, stature estimation remains plagued by two methodological problems: (1) the choice of the statistical estimator, and (2) the choice of the reference population from which to derive the parameters. This work addresses both of these problems in estimating stature for fossil hominids, with special reference to A.L. 288-1 (Australopithecus afarensis) and WT 15000 (Homo erectus). Three reference samples of known stature with maximum humerus and femur lengths are used in this study: a large (n=2209) human sample from North America, a smaller sample of modern human pygmies (n=19) from Africa, and a sample of wild-collected African great apes (n=85). Five regression techniques are used to estimate stature in the fossil hominids using both univariate and multivariate parameters derived from the reference samples: classical calibration, inverse calibration, major axis, reduced major axis and the zero-intercept ratio model. We also explore a new diagnostic to test extrapolation and allometric differences with multivariate data, and we calculate 95% confidence intervals to examine the range of variation in estimates for A.L. 288-1, WT 15000 and the new Bouri hominid (contemporary with [corrected] Australopithecus garhi). Results frequently vary depending on whether the data are univariate or multivariate. Unique limb proportions and fragmented remains complicate the choice of estimator. We are usually left in the end with the classical calibrator as the best choice. It is the maximum likelihood estimator that performs best overall, especially in scenarios where extrapolation occurs away from the mean of the reference sample. The new diagnostic appears to be a quick and efficient way to determine at the outset whether extrapolation exists in size and/or shape of the long bones between the reference sample and the target specimen.
Collapse
Affiliation(s)
- S M Hens
- Department of Cell Biology and Anatomy, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA.
| | | | | |
Collapse
|
19
|
|
20
|
Konigsberg LW, Hens SM, Jantz LM, Jungers WL. Stature estimation and calibration: Bayesian and maximum likelihood perspectives in physical anthropology. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 1998. [DOI: 10.1002/(sici)1096-8644(1998)107:27+<65::aid-ajpa4>3.0.co;2-6] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|