Dispersion dimorphism in human populations

Abstract

The aim of this paper is to verify the existence of dispersion (or variability) dimorphism in several anthropometric traits, i.e., some skeletal, muscular, and adipose dimensions, and to provide an evaluation of this scarcely considered aspect of sex differences. This research focuses on two human samples from two different European regions, Sardinia (Italy) and the Basque Country (Spain). Twenty-three anthropometric measurements were taken. A first qualitative analysis was carried out comparing the profiles of the coefficients of variation of each variable in both sexes. Secondly, the equality of variability was verified with different tests. In the normal case, Student's t-test, as proposed by Sokal and Braumann ([1980] Syst. Zool. 29:50-63), was applied. In the more general case, it was necessary to resort to resampling techniques. A suitable bootstrap test was constructed and the results were compared, when possible, with those obtained by other methods. The measurements showed parallel trends in the two populations. In particular, subcutaneous skinfolds showed significant dispersion dimorphism, with the greatest coefficients of variation in men. We suggest that this result was linked to stronger canalization in female dimensions related to the reproductive function and influenced by sociocultural factors. We also suggest defining dispersion dimorphism, whose existence is confirmed by the results presented in this paper, as a descriptive pattern of phenotype variability in both sexes that can be specific of a given class of anthropometric traits.

Testing the equality of two coefficients of variation: a new Bayesian approach

“…Based on the BDM we conclude that only one hypothesis can be rejected, that is the equality between the coefficients of variation for men's and women's skinfolds tricepts. The final conclusions go in the same direction as [10].…”

“…We focus on the CVs comparisons among men and women. The same data were presented and analysed in [10], where the bootstrap test for the difference of CVs developed in [5] was applied to evaluate sexual dimorphism. Among the 20 measurements in the dataset, we applied the Bayesian Discrepancy Test to a subsample of 10 which can be assumed to be normally distributed.…”

“…In this analysis we consider a small selection of 3 miRNAs among those which were found to be differentially expressed (see [18]). Given that we only know the posterior distribution up to a normalising constant, the application of MCMC methods is necessary in order to calculate the probabilities (10). In particular, following the literature on Bayesian inference for a Skew-Normal distribution (see [16]), a Gibbs-sampler has been used.…”

Ethnic variability of growth processes through the prism of sexual dimorphism of body dimensions (based on data of early and first childhood children)

“…Однако в подобных работах редко уделяется специальное внимание проблеме полового диморфизма морфофункционального статуса и ростовых процессов как количественной характеристике и маркеру межгруппового разнообразия. В настоящей работе подтверждено, что ПД размеров тела является, вне зависимости от возраста обследованного контингента, самостоятельным информативным количественным индикатором межгруппового соматического разнообразия, маркируя разные стратегии адаптации и разную экочувствительность мужского и женского пола в целом [Зимина, 2019;Stinson, 1985;, в том числе в связи с этническим фактором [Дерябин, 2008;Зимина, 2019;Marini et al, 2005;.…”

Morphofunctional adaptation of young students living in different cities of Russia

“…Ïðè ýòîì èíòåðåñíî îòìåòèòü, ÷òî þíîøåé ñ íèçêèì ÓÔÑ â Àðõàíãåëüñêå (24%) â 2 ðàçà áîëüøå, ÷åì äåâóøåê ñ òàêèìè aeå ïîêàçàòåëÿìè (12%; p=0,013). Ýòè äàííûå ïîäòâåðaeäàþò øèðîêî ðàñïðîñòðàíåííóþ ãèïîòåçó î áîëüøåé ñåíñèòèâíîñòè ìóaeñêîãî ïîëà ê ñòðåññîâîìó âîçäåéñòâèþ ýêîëîãè÷åñêèõ è ñîöèàëüíûõ ôàêòîðîâ [Ãåîäàêÿí, 2004;Buffa et al, 2001;Marini et al, 2005]. Ïî ðåçóëüòàòàì ñðàâíèòåëüíîãî àíàëèçà ïîêàçàòåëåé îáùåé àäàïòàöèè (ïî ìåòîäó Áàåâñêîãî [Áàåâñêèé, Áåðñåíåâà, 2008]) íàèáîëüøåå êîëè÷åñòâî ïðåäñòàâèòåëåé ñ íåóäîâëåòâîðèòåëüíîé àäàïòàöèåé è ñðûâîì àäàïòàöèè â íàøåì èññëåäîâàíèè âûÿâëåíî ó þíîøåé è äåâóøåê èç Àðõàíãåëüñêà è Ñàðàíñêà (òàáë.…”