Long Bone Length, Stature and Time in the European Late Pleistocene and Early Holocene

185

237

The difficult birth process of humans, often described as the ''obstetric dilemma,'' is commonly assumed to reflect antagonistic selective pressures favoring neonatal encephalization and maternal bipedal locomotion. However, cephalo-pelvic disproportion is not exclusive to humans, and is present in some primate species of smaller body size. The fossil record indicates mosaic evolution of the obstetric dilemma, involving a number of different evolutionary processes, and it appears to have shifted in magnitude between Australopithecus, Pleistocene Homo, and recent human populations. Most attention to date has focused on its generic nature, rather than on its variability between populations. We reevaluate the nature of the human obstetric dilemma using updated hominin and primate literature, and then consider the contribution of phenotypic plasticity to variability in its magnitude. Both maternal pelvic dimensions and fetal growth patterns are sensitive to ecological factors such as diet and the thermal environment. Neonatal head girth has low plasticity, whereas neonatal mass and maternal stature have higher plasticity. Secular trends in body size may therefore exacerbate or decrease the obstetric dilemma. The emergence of agriculture may have exacerbated the dilemma, by decreasing maternal stature and increasing neonatal growth and adiposity due to dietary shifts. Paleodemographic comparisons between foragers and agriculturalists suggest that foragers have considerably lower rates of perinatal mortality. In contemporary populations, maternal stature remains strongly associated with perinatal mortality in many populations. Long-term improvements in nutrition across future generations may relieve the dilemma, but in the meantime, variability in its magnitude is likely to persist. Yrbk Phys The notion that maternal pelvic dimensions are subject to powerful competing demands from reproduction and locomotion is widely accepted in the biomedical and anthropological literature (Krogman, 1951;Washburn, 1960;Schultz, 1969;Rosenberg, 1992;Rosenberg and Trevathan, 1996;Wittman and Wall, 2007;Walsh, 2008;Franciscus, 2009;Trevathan, 2011). The maternal pelvis is frequently considered to be subject to two counteracting evolutionary forces: decreased height and increased mediolateral breadth in order to optimize the biomechanics of locomotion, and increased anteroposterior dimensions in order to enable birth of the unusually encephalized human infant. The compromise imposed by these antagonistic demands manifests as a difficult passage of the fetal head through the birth canal (Wittman and Wall, 2007), resulting in the birth process being a more complex and lengthy procedure in humans than in closely related species of ape (Tevathan, 1988;Rosenberg, 1992;Rosenberg and Trevathan, 2002). The antagonistic interaction of bipedalism and encephalization has been assumed to have followed the emergence of the large Homo brain within the last 2 million years (Martin, 1983).In addition to shaping the unusual mechanism of birth, h...

Section: Long‐term Trends In Staturementioning

confidence: 99%

The obstetric dilemma: An ancient game of Russian roulette, or a variable dilemma sensitive to ecology?

Wells¹,

DeSilva

Stock³

2012

185

237

“…A number of different formulae have been used to estimate stature from long bone lengths in European archeological material (e.g., see Sjøvold,1990; Hanson,1992; Formicola,1993; Giannecchini and Moggi‐Cecchi,2008; Vercellotti et al,2009; Meiklejohn and Babb,2011). Among the most widely used formulae are those of Trotter and Gleser (1952, 1958), based on modern US samples.…”

mentioning

confidence: 99%

Stature and body mass estimation from skeletal remains in the European Holocene

Ruff

Holt

Niskanen

et al. 2012

232

276

Techniques that are currently available for estimating stature and body mass from European skeletal remains are all subject to various limitations. Here, we develop new prediction equations based on large skeletal samples representing much of the continent and temporal periods ranging from the Mesolithic to the 20th century. Anatomical reconstruction of stature is carried out for 501 individuals, and body mass is calculated from estimated stature and biiliac breadth in 1,145 individuals. These data are used to derive stature estimation formulae based on long bone lengths and body mass estimation formulae based on femoral head breadth. Prediction accuracy is superior to that of previously available methods. No systematic geographic or temporal variation in prediction errors is apparent, except in tibial estimation of stature, where northern and southern European formulae are necessary because of the presence of relatively longer tibiae in southern samples. Thus, these equations should bebroadly applicable to European Holocene skeletal samples.

“…New methods of estimating stature are being published regularly with higher levels of precision for a chronologically and geographically diverse array of samples, including native North Americans (Auerbach and Ruff, 2010), ancient Egyptians (Raxter et al, 2008), and late Pleistocene and Holocene Europeans (Meiklejohn and Babb, 2011;Ruff et al, 2012). New methods of estimating stature are being published regularly with higher levels of precision for a chronologically and geographically diverse array of samples, including native North Americans (Auerbach and Ruff, 2010), ancient Egyptians (Raxter et al, 2008), and late Pleistocene and Holocene Europeans (Meiklejohn and Babb, 2011;Ruff et al, 2012).…”

mentioning

confidence: 99%

“…The study of stature in recent humans and in our fossil ancestors is currently experiencing a renaissance. New methods of estimating stature are being published regularly with higher levels of precision for a chronologically and geographically diverse array of samples, including native North Americans (Auerbach and Ruff, 2010), ancient Egyptians (Raxter et al, 2008), and late Pleistocene and Holocene Europeans (Meiklejohn and Babb, 2011;Ruff et al, 2012). Important anthropological issues that focus on stature as a critical variable include: the biological consequences of the origin and intensification of agriculture (Auerbach, 2011;Mummert et al, 2011), evolutionary changes in body proportions and body mass (Ruff and Walker, 1993;Ruff, 2000;Pomeroy and Stock, 2012), and regional variation in secular trends (Malina et al, 2010;Shin et al, 2012).…”

mentioning

confidence: 99%

Stature in Holocene foragers of North India

Lukacs

Pal

Nelson

2013

The Ganga Plain of North India provides an archaeological and skeletal record of semi-nomadic Holocene foragers in association with an aceramic Mesolithic culture. Prior estimates of stature for Mesolithic Lake Cultures (MLC) used inappropriate equations from an American White reference group and need revision. Attention is given to intralimb body proportions and geo-climatic provenance of MLC series in considering the most suitable reference population. Regression equations from ancient Egyptians are used in reconstructing stature for MLC skeletal series from Damdama (DDM), Mahadaha (MDH), and Sarai Nahar Rai (SNR). Mean stature is estimated at between 174 (MDH) and 178 cm (DDM and SNR) for males, and between 163 cm (MDH) and 179 cm (SNR) for females. Stature estimates based on ancient Egyptian equations are significantly shorter (from 3.5 to 7.1 cm shorter in males; from 3.2 to 7.5 cm shorter in females) than estimates using the American White reference group. Revised stature estimates from tibia length and from femur + tibia more accurately estimate MLC stature for two reasons: a) these elements are highly correlated with stature and have lower standard estimates of error, and b) uncertainty regarding methods of measuring tibia length is avoided. When compared with Holocene samples of native Americans and Mesolithic Europeans, MLC series from North India are tall. This aspect of their biological variation confirms earlier assessments and results from the synergistic influence of balanced nutrition from broad-spectrum foraging, body-proportions adapted to a seasonally hot and arid climate, and the functional demands of a mobile, semi-nomadic life-style.