Dimorphism In Stature Research Articles

Latitudinal patterns in human stature and sexual stature dimorphism

Background: There exists substantial variation in human stature and sexual stature dimorphism that has been attributed to both genetic and environmental variables. A few studies have previously investigated possible relationships between latitude and stature, building on the idea that variation in climate can influence body size (Bergmann's rule). This change in body size can in turn have influenced sexual stature dimorphism (in accordance with Rensch's rule).Aim: The present study investigated whether latitude is associated with variation in human mean stature and sexual stature dimorphism.Subjects and methods: Phylogenetic and non-phylogenetic analyses were conducted on a cross-cultural sample of 124 human populations.Results: The results indicate that both male and female mean stature increase with increasing distance from the equator. While sexual stature dimorphism also was positively related to latitude in the non-phylogenetic test, this relationship disappeared when using a phylogenetic comparative method. Evidence was also found for curved relationships between latitude and both male and female stature, as well as stature dimorphism, all indicating a maximum at around 40° from the equator.Conclusions: The results of the present study indicate that both male and female stature are weakly associated with latitude. It is possible that these relationships are evolved responses to variation in climate. No unequivocal conclusion could be drawn regarding a possible relationship between latitude and sexual stature dimorphism.

Variable preferences for sexual dimorphism in stature (SDS): Further evidence for an adjustment in relation to own height

In contemporary Western populations, some physical characteristics are sexually dimorphic, and it is known that these traits also affect human mate preferences. Height is one such characteristic, and evidence suggests that females prefer taller over shorter males, indeed, taller males have been found to have greater reproductive success. However, relative height is also important with ‘Sexual Dimorphism in Stature’ (SDS) calculated as male height/female height. Pawlowski (2003) showed that people adjust their preferences for SDS in relation to their own height in order to increase their potential pool of partners. The aim of the present study was to replicate Pawlowski’s study on a larger sample of participants, and to investigate the universality of the reported preference adjustment within European societies. We present data of 1102 men and women from three countries (Germany, Austria, and the UK) that confirm Pawlowski’s original data on a Polish sample. Moreover, the mechanism of an adjustment of SDS preferences in relation to own height was found in all three countries, suggesting that height dependent partner preference is a genuine feature in Western societies.

Stature and sexual stature dimorphism in Sweden, from the 10th to the end of the 20th century

Mean stature in a population has been observed to vary with living conditions. If, and how, this affects sexual dimorphism in stature is not fully understood. We analyzed stature data from Swedish populations from the 10th to the end of the 20th century to investigate if male stature is more plastic than female stature in response to environmental changes. Further, we examined if there, as a consequence of this, exists an allometric relationship between male and female stature that is not caused by genetic factors, coupling greater stature with greater dimorphism. We found no significant change in stature from the 10th century to the 17th century, but a clear increase in both male and female stature during the 20th century, most likely because of improved living conditions. Regression analyses revealed no consistent change in sexual stature dimorphism over time for any of the time periods, including the 20th century. Further, we found no significant allometric relationship between male and female stature, and could consequently not identify any significant relationship between stature and stature dimorphism. Thus, contrary to previous suggestions, the regressions did not provide support for the assertion that male stature is more sensitive to environmental changes than female stature, nor that stature dimorphism increases with increasing stature.

Sexual dimorphism in stature of adult Northern Nigerians

The present study investigated sexual dimorphism in stature (height) of a population of northern Nigerians resident in the Ilorin Township. The study population comprised two hundred and fifty (250) young adults; this consisted of 150 males and 100 females, aged 18 –29 years. In each subject, height was measured using the Avery height and weight scale; from the data obtained, absolute and relative sex difference in stature were extrapolated. A value of 5.5% was obtained for relative sex difference in stature of the study population; this indicates that northern Nigerians have the least sexual dimorphism in stature when compared to the values of 5.9% and 5.7% earlier reported for western and eastern Nigerians respectively. The regional variation in sex dimorphism in stature of adult Nigerians, as observed in this study, was possibly due to a combination of nutritional, socio-economic and genetic factors. Keywords: sexual dimorphism in adult stature The Tropical Journal of Health Sciences Vol. 13(1) 2006: 33-35

Women's preferences for sexual dimorphism in height depend on menstrual cycle phase and expected duration of relationship

Human mate preferences are related to many morphological traits, such as female waist-to-hip ratio (WHR), body mass index (BMI), male height or facial symmetry. People also vary in preferences for sexual dimorphism in stature (SDS = male height/female height) between themselves and a potential partner. Here, we demonstrate that women adjust their preference for SDS not only in relation to their own height but also in relation to (1) the phase of menstrual cycle during which their preferences were studied and (2) the sexual strategy (short- versus long-term) they were asked to choose. Taller males (larger SDS) were preferred more often when women were in the follicular (i.e. fertile) phase of their menstrual cycle and when the partners were chosen for short-term relationships. These effects were independent of woman's height. The results show that women in a potentially fertile phase of their menstrual cycle and when choosing a partner who might be less likely to invest in children select genes of taller males.

Variable preferences for sexual dimorphism in height as a strategy for increasing the pool of potential partners in humans.

Human mate preferences are known to be related to a number of morphological traits. Those relating to female waist-to-hip ratio or body mass index and to male height appear to be distinctive mate-choice criteria and are known to be related to reproductive success. In addition to absolute height, a possibly important mate-choice criterion may be relative height, i.e. the extent of sexual dimorphism in stature (SDS = male height/female height) between oneself and a potential partner. Here, I demonstrate that people adjust their preferences for SDS in relation to their own height in order to increase the potential pool of partners. This causes nonlinearity in assortative mating in relation to height and shows that in relation to intrapopulational SDS both men and women are responsible for stabilizing selection.

Human fertility variation, size-related obstetrical performance and the evolution of sexual stature dimorphism.

In several animal species, change in sexual size dimorphism is a correlated response to selection on fecundity. In humans, different hypotheses have been proposed to explain the variation of sexual dimorphism in stature, but no consensus has yet emerged. In this paper, we evaluate from a theoretical and an empirical point of view the hypothesis that the extent of sexual dimorphism in human populations results from the interaction between fertility and size-related obstetric complications. We first developed an optimal evolutionary model based on extensive simulations and then we performed a comparative analysis for a total set of 38 countries worldwide. Our optimization modelling shows that size-related mortality factors do indeed have the potential to affect the extent of sexual stature dimorphism. Comparative analysis using generalized linear modelling supports the idea that maternal death caused by deliveries and complications of pregnancy (a variable known to be size related) could be a key determinant explaining variation in sexual stature dimorphism across populations. We discuss our results in relation to other hypotheses on the evolution of sexual stature dimorphism in humans.

Sexual dimorphism in stature and women's work: A phylogenetic cross-cultural analysis

The following cultural variables were tested for their association with sexual dimorphism: sexual division of labor, type of subsistence (hunting and agriculture), and polygyny. The transmission of these traits among populations was investigated. All the traits were found to be associated with phylogeny, indicating that they are inherited from mother to daughter populations. A cross-cultural comparative method was used which controls for the statistical effects of similarity due to common ancestry (Galton's problem). Cross-cultural variation in sexual dimorphism in stature is negatively associated with women's contribution to subsistence. Women are taller, relative to men, in societies where women contribute more to food production. This may be because female nutritional status is better in these societies. No relationship was found between sexual dimorphism and other aspects of subsistence or polygyny. These results are discussed in relation to other studies of sexual dimorphism in modern and archaeological populations, and in relation to cross-cultural variation in sex-biased parental investment.

Sexual dimorphism in stature and women's work: A phylogenetic cross‐cultural analysis

Sexual dimorphism in stature and women's work: A phylogenetic cross‐cultural analysis

Inuit Sex-Ratio Variation: Population Control, Ethnographic Error, or Parental Manipulation? [and Comments and Reply

Inuit Sex-Ratio Variation: Population Control, Ethnographic Error, or Parental Manipulation? [and Comments and Reply

Femoral lengths and stature in Plio‐Pleistocene hominids

This study reports the femoral lengths of 31 Plio-Pleistocene hominids dated between 3.1 and 0.7 million years ago, and uses those lengths to estimate stature by way of the femur-stature ratio reported by Feldesman et al. (Am. J. Phys. Anthropol. 78:219-220, 1989). By this method the average female Australopithecus afarensis is 105 cm and the average male is 151 cm. The respective values are 115 and 138 cm for A. africanus. As defined by Howell (In VJ Maglio and HBS Cooke (eds): The Evolution of African Mammals. Cambridge: Harvard University Press, 1978) and Johanson et al. (Kirtlandia 28:1-14, 1978), Homo habilis is a sexually dimorphic species, with females standing 118 cm and males 157 cm. Such apparently strong dimorphism may be due to the possibility that there are actually two species of nonrobust hominids between 2 and 1.7 m.y.a. The estimate for the female Australopithecus boisei is 124 cm and for the male, 137 cm, but these estimates are especially difficult to be certain of because there are no femora that can be positively identified as male A. boisei. Australopithecus robustus is estimated to be 110 cm (female) and 132 cm (male). African Homo erectus stood 160 cm (female) and 180 cm (male). From these estimates several generalizations are apparent. First, there is apparently strong sexual dimorphism in stature in A. afarensis and H. habilis, but less in the other species. Second, the "robust" australopithecines were relatively small statured. Third, it is apparently not true that humans have been getting progressively taller throughout their evolutionary history. Some individuals were as tall as modern humans 3 m.y.a., by 2 m.y.a. one individual stood about 173 cm, and by 1.7 m.y.a. a stature of 180+ cm was not uncommon.

Subsistence practices and human sexual dimorphism of stature

Hypotheses recently advanced by Brace & Ryan (1980) and Frayer (1980) suggest links between changes in human sexual dimorphism and changes in technology and subsistence practices. In this paper we test these hypotheses using a sample of extant human groups. Results indicate that extant agriculturalists exhibit a greater degree of sexual dimorphism in stature than extant hunter-gatherers. Moreover, the data analysed in this paper do not indicate that a more equal division of labor is associated with a decrease in human height sexual dimorphism.

Stature at Tikal, Guatemala: Implications for Ancient Maya Demography and Social Organization

AbstractThis paper presents an analysis of stature of the prehistoric population from the Maya site of Tikal, Guatemala. From this analysis, based on 55 skeletons from the Tikal burial series, three important conclusions emerge with respect to ancient Maya demography and social organization. (1) Tikal was settled by people of moderate stature, and this remained relatively stable over several centuries. A marked reduction in male stature in Late Classic times may be indicative of a situation of nutritional stress, which may have had something to do with the collapse of Classic Maya civilization. (2) Stature differences between those buried in tombs and others at Tikal suggest that, in the last century B.C., a distinct ruling class developed at Tikal. This simple class division of rulers and commoners may have become more complex in Late Classic times. (3) There was a marked sexual dimorphism in stature between males and females at Tikal. This is probably partially genetic and partially a reflection of relatively lower status for women as opposed to men in Maya society.