Biohistory of slavery and blood pressure differences in blacks today. A hypothesis.

Abstract

Genetic factors are known to play an important role in the variations in blood pressure levels. However, genetic factors that explain the higher average blood pressure levels of western hemisphere blacks when compared with African blacks have not been seriously considered. Because the genetic makeup of a population is largely determined by biological and ecological forces in the past, an examination of the biohistory of blacks, specifically the slavery era, was conducted. An overview of the salient findings of that investigation is included in this article. The published historical evidence on the transatlantic slave trade and New World slavery (from the 16th century to the 19th century) reveals that conditions existed for "natural selection," and therefore, genetic changes were virtually inevitable in the slave populations. During this period of history, mortality was extremely high, and fertility (or reproductive success) was so low among the survivors that most plantation societies in the western hemisphere depended on a constant importation of captives (over 12 million) from Africa for the viability of the plantation communities. Because the major causes of death were salt-depletive diseases such as diarrhea, fevers, and vomiting, it is argued that individuals with an enhanced genetic-based ability to conserve salt had a distinct survival advantage over others and were, therefore, more likely to bequeath their genotype to subsequent generations of Western hemisphere blacks. Thus, it is predicted that blacks in the Americas have a greater frequency of individuals with an enhanced genetic-based ability to conserve salt than African blacks. Moreover, it is surmised that this trait is partially responsible for the higher incidence of hypertension today among western hemisphere blacks than among African blacks. Ways of testing this hypothesis are suggested by the authors.

A General Model of the Relationship between the Apportionment of Human Genetic Diversity and the Apportionment of Human Phenotypic Diversity

“…Piel et al, 2010). In many other cases of phenotypic difference, hypotheses of divergent selection-sometimes paired with gene-environment interaction-have also been proposed (Knowler et al 1983;Meindl, 1987;Zlotogora et al, 1988;Wilson & Grim, 1991;Bindon & Baker, 1998). Many such hypotheses have been criticized individually (Curtin 1992;Risch et al 2003), and concern has been raised that selective explanations for differences in health outcomes often experience a degree of endurance and importance unwarranted by the evidence (Kaufman & Hall, 2003).…”

Impact of Nativity and Race on “Stroke Belt” Mortality

“…As discussed, the mechanisms by which nativity might influence risk for cerebrovascular death are not identified by this study, although several possibilities exist. These include differences in compliance with medical care practices acquired from different regions, 24 -26 differences in dietary habits and lifestyles, [27][28][29][30] transmission of genetic susceptibility for stroke among blacks originally immigrating from West Africa, [31][32][33] and higher prevalence of low birth weight and subsequent adverse health outcomes. 34 -38 …”

19. Molekularbiologische Sozialwissenschaft?

“…So zeigt eine aktuelle schwedische Studie aus der Physiologie (Barrès et al, 2012) (Chakravarthy et al, 2004;Neel, 1962). Auf ähn-liche Art und Weise erklären manche Biologen das erhöhte Herzkreislaufrisiko der afroamerikanischen Bevölkerung der USA mit der Selektion auf den Sklavenschiffen (Wilson et al, 1991). Epigenetische Befunde werden so genutzt, einfache bio-oder kulturdeterministische Erklärungen von Risikoverteilungen zu kritisieren (Kuzawa et al, 2009 Borghol et al, 2012).…”