Isolation by distance between spouses and its effect on children's growth in height

Abstract

Heterosis is thought to be an important contributor to human growth and development. Marital distance (distance between parental birthplaces) is commonly considered as a factor favoring the occurrence of heterosis and can be used as a proximate measure of its level. The aim of this study is to assess the net effect of expected heterosis resulting from marital migration on the height of offspring, controlling for midparental height and socioeconomic status (SES). Height measurements on 2,675 boys and 2,603 girls ages 6 to 18 years from Ostrowiec Świętokrzyski, Poland were analyzed along with sociodemographic data from their parents. Midparental height was calculated as the average of the reported heights of the parents. Analyses revealed that marital distance, midparental height, and SES had a significant effect on height in boys and girls. The net effect of marital distance was much more marked in boys than girls, whereas other factors showed comparable effects. Marital distance appears to be an independent and important factor influencing the height of offspring. According to the "isolation by distance" hypothesis, greater distance between parental birthplaces may increase heterozygosity, potentially promoting heterosis. We propose that these conditions may result in reduced metabolic costs of growth among the heterozygous individuals.

Human stature in the Near East and Europe ca. 10,000–1000 BC: its spatiotemporal development in a Bayesian errors-in-variables model

“…Increased spatial mobility is likely to have resulted in increasingly mixed gene pools in the populations of the Old World. In such populations, heterosis effects, i.e., the observation that genetically remote individuals have larger offspring (Kozieł et al 2011), might not only have increased stature variability but also average stature. Moreover, increased social mobility as a by-effect of social stratification is thought to be associated with stature increase due to the so-called community effect that views stature as a biologically expressed signal on social status (Bogin et al 2015;Hermanussen and Scheffler 2016).…”

“…As a highly complex trait, it is thought to be determined by genetic factors by up to 90% (Silventoinen 2003;Lango Allen et al 2010;Dubois et al 2012;Wood et al 2014), and the responsible genes are not distributed equally between populations (Turchin et al 2012). In addition, heterosis effects are discussed based on the observation that genetically remote individuals have larger offspring (Kozieł et al 2011), and molecular epigenetics suggest that prenatal exposure to adverse conditions can have lasting consequences for the life course (Heijmans et al 2008;Tobi et al 2014), while it even appears possible that poor health can be passed on to later generations (Gowland 2015). Moreover, stature can also be modified on the phenotypic level, since detrimental natural and sociocultural conditions during the growth period can cause adult stature to stay behind the genetic potential.…”

Heterosis: Many Genes, Many Mechanisms—End the Search for an Undiscovered Unifying Theory

“…However, many interspecific hybrids suffer from reduced longevity and reductions in fertility. Heterosis in humans has been proposed, sometimes controversially, to affect multiple phenotypes including attractiveness [1], IQ [2,3], and height [4][5][6]. In agricultural settings, there are numerous examples in which heterosis has been harnessed to create more productive and more uniform products including livestock [7][8][9][10][11] and crop plants (reviewed in [12][13][14][15][16][17][18][19]).…”

Effect of marital distance on birth weight and length of offspring

“…Thus, in both cases possible benefits of heterosis, such as better growth and development outcomes may be attributed to a higher level of heterozygosity of offspring whose parents' marital distance was greater (for more discussion see: Kozieł et al 2011).…”