A Pre-registered Meta-analysis Based on Three Empirical Studies Reveals No Association Between Prenatal (Amniotic) Cortisol Exposure and Fluctuating Asymmetry in Human Infants

Developmental instability (DI) reflects an organism’s inability to develop an ideal phenotype when challenged by genetic and environmental insults. DI can be estimated via the proxy measure of fluctuating asymmetry (FA), i.e., the small random deviations from perfect bilateral symmetry observed in the morphology of paired traits. The mechanisms involved in the genesis of FA in human populations are relatively unknown, though animal research indicates that hormonal processes may be involved. As maternal stress during pregnancy is detrimental to various developmental processes, elevated prenatal cortisol may represent a causal factor in the subsequent emergence of an asymmetrical phenotype. The main purpose of this pre-registered meta-analysis based on three empirical studies was to investigate whether mid-trimester amniotic cortisol levels predict subsequent FA in finger lengths of infants from Germany, Portugal, and the UK. No statistically significant relationships were observed, and meta-analytic combination of the effect size estimates yielded a null result. We did, however, detect significant positive correlations between the cortisol present in the amniotic fluid and maternal plasma in the Portuguese cohort, and observed that FA in the German cohort was significantly lower at 70-months than at either 9- or 20-months. Taken together, the current findings run contrary to animal research showing that elevated prenatal corticosterone exposure leads to increased FA. However, this may be because a single cortisol assay obtained via amniocentesis is an inadequate proxy for average gestational exposure, and/or that prenatal cortisol levels at an earlier (i.e., first rather than second trimester) stage of pregnancy is what explains variance in subsequent FA.publishersversionpublishe

A Comparison of Craniofacial Asymmetry in Gorilla gorilla gorilla and Pan troglodytes troglodytes

Fluctuating asymmetry (FA) – random deviations from bilateral symmetry in an organism’s paired features – is a good candidate for investigating developmental stability. This easily accessible measurement can be used to understand the relationship between stress and development across organisms, and growth rate plays a vital role in developmental processes. Few studies have investigated craniofacial FA in non-human primates, and those that have suggest that levels of FA are higher in slower growing species. This study examines craniofacial FA in two primate species (Pan troglodytes troglodytes and Gorilla gorilla gorilla; n=81) to elucidate the effect of growth rate on FA in non-human apes. Results suggest that Gorilla exhibits higher levels of FA than Pan, and male gorillas show higher levels of FA than female gorillas. These results indicate that FA is correlated with growth rate, meaning that species with slower growth (i.e., Pan) may have greater developmental stability. Further analyses will help tease apart the factors contributing to differential response to environmental and genetic stress to contribute to a broader understanding of primate canalization and developmental stability

Understanding the Environmental and Genetic Influence on Fluctuating Asymmetry and Developmental Instability in Primates

This dissertation explored the impact of environmental factors on the development and perpetuation of fluctuating asymmetry (FA) and sought to understand the role evolution may play in the FA exhibited in two primate populations: the free-ranging Cayo Santiago rhesus macaques (Macaca mulatta) and the Southwest National Primate Research Center olive baboons (Papio hamadryas anubis). Demographic, ontogenetic, secular, external, and genetic factors were examined. Specifically, this dissertation investigated FA over all ontogenetic stages, across decades, between sexes, in association with ecological catastrophes, and with tooth pathology to try and tease apart factors that may influence FA and developmental instability. This dissertation also estimated the heritability and evolvability of FA and used FA levels over decades to examine the role of evolutionary mechanisms on FA. In all, results show that the age at which a macaque experiences a hurricane and baboon antemortem tooth loss impact levels of FA. They also show that sex-related differences are present in the population of baboons but not the macaques. Additionally, FA does not seem to change ontogenetically in either the macaque or baboon population, and secular changes were only found in male baboons where FA decreased over time. Lastly, the heritability and evolvability of FA in the macaque and baboon populations were extremely low, though higher in baboons than macaques. This work suggests that FA levels may be sex-specific in species with extreme sexual dimorphism, and FA generally seems not to change over ontogeny in these populations. Secular changes in FA appear possible in primates, although the pattern remains ambiguous. This work also shows that ecological catastrophes such as hurricanes are likely critical determinants of FA later in life if experienced in utero. Lastly, FA seems to have some additive genetic variation that is subject to selection, though minimal. Overall, this work offers additional resolution in teasing apart factors contributing to FA and points to minimal genetic influence on FA levels

Understanding the Environmental and Genetic Influence on Fluctuating Asymmetry and Developmental Instability in Primates

This dissertation explored the impact of environmental factors on the development and perpetuation of fluctuating asymmetry (FA) and sought to understand the role evolution may play in the FA exhibited in two primate populations: the free-ranging Cayo Santiago rhesus macaques (Macaca mulatta) and the Southwest National Primate Research Center olive baboons (Papio hamadryas anubis). Demographic, ontogenetic, secular, external, and genetic factors were examined. Specifically, this dissertation investigated FA over all ontogenetic stages, across decades, between sexes, in association with ecological catastrophes, and with tooth pathology to try and tease apart factors that may influence FA and developmental instability. This dissertation also estimated the heritability and evolvability of FA and used FA levels over decades to examine the role of evolutionary mechanisms on FA. In all, results show that the age at which a macaque experiences a hurricane and baboon antemortem tooth loss impact levels of FA. They also show that sex-related differences are present in the population of baboons but not the macaques. Additionally, FA does not seem to change ontogenetically in either the macaque or baboon population, and secular changes were only found in male baboons where FA decreased over time. Lastly, the heritability and evolvability of FA in the macaque and baboon populations were extremely low, though higher in baboons than macaques. This work suggests that FA levels may be sex-specific in species with extreme sexual dimorphism, and FA generally seems not to change over ontogeny in these populations. Secular changes in FA appear possible in primates, although the pattern remains ambiguous. This work also shows that ecological catastrophes such as hurricanes are likely critical determinants of FA later in life if experienced in utero. Lastly, FA seems to have some additive genetic variation that is subject to selection, though minimal. Overall, this work offers additional resolution in teasing apart factors contributing to FA and points to minimal genetic influence on FA levels

Facial fluctuating asymmetry in three species of colobus monkeys

Fluctuating asymmetry (FA) in biological structures has historically been used as a proxy for developmental instability (DI), and therefore stress in development. Facial bones, specifically cranial bones, are of particular interest for FA analysis. To better understand differences in environmental stressors, particularly in the context of anthropogenic change, facial FA has been quantified in three species of colobus monkeys; two of these species (Piliocolobus badius and Colobus polykomos) are sympatric and inhabit the Taï region of Côte d'Ivoire. An additional population of southern Kenyan C. angolensis palliatus was included for comparative analysis; these populations represent a gradient of stress. Landmarks were imposed on primate crania using Viewbox 4 software; using geomorph and morphoJ, relative differences in FA were quantified through PCAs and FA component variance tests. The results from this project offer weak support in favor of this gradient, with significant evidence (p=0.035) suggesting this population of Taï P. badius demonstrates a greater response to stress than the population of C. angolensis palliatus. Given recent alarming trends in P. badius conservation, future work comparing responses to stress among various populations and species of Piliocolobus is desired.No embargoAcademic Major: Anthropological Science

Facial attractiveness among rhesus macaques (Macaca mulatta) : manipulating and measuring preferences for conspecifics' facial characteristics

The face holds a central role in both human and nonhuman primate social interactions, through the communication of feelings and intentions via facial expressions and by acting as a means of recognising individuals. Humans, however, also employ their faces in mate attraction and assessment, an area that has received little attention in nonhuman primates. Many researchers have proposed that human aesthetic judgments of facial attractiveness have a biological basis, and these preferences have evolved via sexual selection processes during human evolution. The use of the face in attractiveness assessments need not be limited to humans. Rather, there is good reason to suggest that this may also apply to other nonhuman primates, based on homologies in the way in which primates use their faces, and on evidence that the face is a site of sexual selection for many primate species. It was the aim of this thesis to explore whether facial traits may also play a role in judgements of attractiveness in a nonhuman primate, the rhesus macaque( Macaca mulatta), in an effort to understand whether humans are unique in utilising the face as a mechanism of mate assessment. Three factors that are reported to influence facial attractiveness in humans are facial symmetry, sexual dimorphism, and averageness. To assess whether they also play a role in nonhuman primates, a series of experiments were conducted where digital images of adult male and female rhesus macaque faces were altered for these features. Opposite-sexed images were then displayed to adult males and females in a captive setting. Eye gaze measures were utilised to assess visual preference for, and the relative importance of, these traits. These experiments yielded mixed results. Increasing facial symmetry of opposite-sexed conspecifics positively influenced the dependent gaze measures employed here. Manipulating degree of facial sexual dimorphism had little influence on the visual gaze of either sex. Facial averageness positively influenced visual preferences for opposite-sexed conspecifics among both sexes, although increasing degree of averageness did not. The last topic to be explored was facial colouration. Rhesus macaques like, various other species of anthropoid primates, possess facial displays of red secondary sexual colouration. As above, animals viewed digitally altered pale and red versions of opposite-sexed conspecifics. Although females displayed preferences for red male faces, males displayed no clear preferences based on female facial colour. This raises the possibility that male and female facial colour may serve different roles in intraspecific signaling. While it cannot be concluded that visual preferences are indeed indicative of real-life preferences, the results do indicate that animals are not indifferent to variations in conspecific facial features. The present findings have important implications regarding the evolution of facial attractiveness, as they provide the first experimental evidence suggesting that facial features may serve as a mechanism for mate selection across primate taxa and that both human and nonhuman primates may employ similar criteria to appraise facial attractiveness

Estudos sobre razão digital (2D:4D) : métodos de medida, força muscular e desempenho esportivo no tênis

Orientador : Profª. Drª. Rosana Nogueira de MoraisTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Biologia Celular e Molecular. Defesa: Curitiba, 19/12/2016Inclui referências : f. 64-72;80-91Área de concentração : FisiologiaResumo: Durante o período embrionário a ação dos androgênios tem papel determinante na diferenciação sexual, no desenvolvimento dos órgãos sexuais masculinos e, naturalmente, produzem efeitos masculinizantes no cérebro. A baixa razão 2D:4D, obtida pela divisão do comprimento do segundo dedo (indicador) pelo quarto dedo (anelar), é apontada como indicador de androgenização pré-natal e associada com desempenho esportivo em muitas modalidades. Nós analisamos a associação da medida da razão 2D:4D com desempenho esportivo, caracteristicas fisicas, psicológicas e hormonais. Foram três estudos apresentados no formato de artigo. No estudo 1 analisanos a medida da razão 2D:4D direta (diretamente na mão do sujeito) e a medida indireta (em imagens da mão por escâner) de 114 homens e 90 mulheres e, adicionalmente, realizamos uma revisão de literatura minuciosa para comparar nossos dados. Demonstramos que há um efeito direcional no qual a medida direta da razão 2D:4D tende a ser maior que a medida indireta, ou seja, a medida indireta superestima o grau de androgenização pré-natal. No estudo 2, avaliamos, a produção de força muscular, liberação de testosterona, cortisol, agressividade e estabilidade emocional em 89 homens adultos, quando expostos a um vídeo contendo imagens de agressão no esporte (situação desafiadora) comparando com os mesmos em situação controle. Foi demostrado que a situação desafiadora modula um aumento de força muscular, de agressividade e de concentração de testosterona e ainda diminui a estabilidade emocional. A maior produção de força na situação de desafio, foi associada por regressão múltipla com baixa razão 2D:4D e a maior controle emocional. No estudo 3, avaliamos a razão 2D:4D de 64 tenistas infanto-juvenis do sexo masculino e observamos que a menor razão 2D:4D foi associada em 35% com melhor desempenho tenístico, em 20% com maior produção de força muscular, em 9% com maior potência muscular de membros inferiores e em 7% com maior índice de autoconfiança. Não encontramos associação da razão 2D:4D com concentrações hormonais, apenas confirmamos o resultado do estudo 2, no qual ocorre um aumento de testosterona em 13% quando os sujeitos foram submetidos aos desafios dos testes físicos. Por fim, indicamos que há associação da razão 2D:4D e desempenho no tênis, porém estudos em mulheres e mais aspectos necessitam ser investigados para entender melhor qual componentes explicam a relação da androgenização pré-natal e desempenho no tênis. Mesmo assim, apresentamos dados suficientes para sugerimos que a medida da razão 2D:4D pode auxiliar treinadores, como medida adicional, na avaliação física de jovens atletas. Palavras-chave: Diferenciação sexual, Razão do dedo, 2D:4D, medida direta e indireta, força estatística, testosterona, agressão, força de preensão manual. 2D:4D.Abstract: Prenatal androgenization plays an important role in human brain development and influences human behaviour. Digit ratio (2D:4D), the relative lengths of the index finger (2D) and the ring finger (4D), is a putative marker for prenatal testosterone and is correlated with performance in many sports. This thesis analysed the relationship between 2D:4D ratio with sport performance and physical, psychological and endocrine characteristics. It divided in three studies, and in the first one we investigated a methodological question regarding 2D:4D measuring. We compared direct versus indirect measurement of digit ratio (114 males and 90 females). And reviewed the literature on this issue. We found that direct 2D:4D measuring tends to be larger than indirect ones, indicating that direct and indirect mean 2D:4D's should not be compared in between-population studies. On the second study, we hypothesised that correlation between 2D:4D and strength may be strongest in challenge conditions when short-term changes occur in steroid hormones. The challenge condition increased Handgrip strength (HGS), and elicited modest changes in testosterone (T), physical aggression and emotional stability. HGS correlated negatively with left hand 2D:4D. In a multiple regression, left hand 2D:4D was negatively related to HGS and emotional stability was positively related to HGS. In the control condition HGS was not correlated with 2D:4D. Our conclusions were that 2D:4D is a negative correlate of strength in challenge situations and this finding may in part explain associations between 2D:4D and sports performance. In the third study, we assessed 64 male junior tennis players and found that low 2D:4D ratios were associated in 35% with better tennis performance, in 20% with higher HGS, in 9% with explosive muscular strength and in 7% with best self-confidence. There was no relationship between 2D:4D ratios and steroid hormones, although, as we found on study two there was a T increase in 13% after the physical tests challenge. Finally, we suggest that there are associations with 2D:4D ratios and junior tennis performance, however, studies in female junior tennis players and other sports-related variables are still needed. We suggest that 2D:4D ratios could help sports coaches as an additional measure on young athlete assessments. Key words: Sexual Differentiation, Digit Ratio, 2D:4D; direct vs indirect measurement; Tennis; Testosterone; Aggression; Hand-grip Strengt

Faculty Publications and Creative Works 1999

One of the ways in which we recognize our faculty at the University of New Mexico is through Faculty Publications & Creative Works. An annual publication, it highlights our faculty\u27s scholarly and creative activities and achievements and serves as a compendium of UNM faculty efforts during the 1999 calendar year. Faculty Publications & Creative Works strives to illustrate the depth and breadth of research activities performed throughout our University\u27s laboratories, studios and classrooms. We believe that the communication of individual research is a significant method of sharing concepts and thoughts and ultimately inspiring the birth of new ideas. In support of this, UNM faculty during 1999 produced over 2,292 works, including 1,837 scholarly papers and articles, 78 books, 82 book chapters, 175 reviews, 113 creative works and 7 patented works. We are proud of the accomplishments of our faculty which are in part reflected in this book, which illustrates the diversity of intellectual pursuits in support of research and education at the University of New Mexico

Cross-sectional examination of sex differences in depressed youth : ruminative response theory, pubertal status, and hormones / by Jennifer L. Welsh.

"Prevalence estimates indicate that during adolescence a shift in the sex ratio of depression occurs that results in twice as many females reporting symptoms as males. The purpose of the current study was to investigate the relationship between this sex shift and a set of risk factors (ruminative coping, pubertal status, and hormones) using the tripartite model. Data were collected from 213 adolescents (between ages 12 and 19) across all stages of pubertal development (pre-, mid-, and post-puberty) through paper and pencil questionnaires and measures of hand features

The role of apparent health in face preferences

This thesis describes a series of empirical studies that investigated the role of apparent health in face preferences. Chapter 1 summarises previous work showing that facial symmetry, averageness and sexual dimorphism influence judgements of facial attractiveness. Chapter 2 describes studies demonstrating that consideration of the role of apparent health in face preferences offers insight into the motivations that underpin attraction to symmetric faces. Chapters 3-5 describe studies demonstrating that, while people generally prefer faces that appear healthy to those that appear unhealthy, characteristics of the judges (e.g. hormonal, health and developmental factors) contribute to systematic variation in women's preferences for apparent health. In the final chapter, a positive link between lifestyle health (e.g. exercise behaviour) and facial health was demonstrated. The findings described in this thesis are evidence that preferences for healthy faces are influenced by biological factors and evidence for accuracy in attributions of health to faces