Repetition of the same pairs of names in marriages in Fogo Island, Newfoundland, and genetic variation

Abstract

Surnames can be used to investigate the genetic structure of human populations. The repeated-pairs approach (RP) uses information on the repetition of the same pairs of names from marital data sets to indicate the influence of clanlike behavior on mate choice. RP estimates the subdivision of the population into subgroups that breed among themselves and the kind of inbreeding ascribed to the Wahlund effect. The application of this method to the Fog0 Island, Newfoundland, data set indicates a large percentage excess of observed over random repetitions. Presumably at least a part of this excess in the island population is due to denominational subdivision and endogamy. The expected relationship between RP and heterozygosity is observed in this case. Given these results, it would seem worthwhile to explore the relationship between the frequency of repetitions of pairs of surnames in marriages and genetic variation in other populations as well and, at the same time, to begin to inquire into the validity of such assumptions concerning the use of surnames as the monophyletic origin of common names.

Effect of Recent Historical Events on Migration and Isonymic Stratification among the Rama Amerindians from Nicaragua

“…If two populations have different allele frequencies, the overall heterozygosity is reduced causing population subdivisions or population substructure which can result from geographic barriers to gene flow (genetic drift) and/or other culturally associated behaviors of preferential mating systems. The resulting impact on gene frequencies is known as the Wahlund effect, which is defined as a reduction of heterozygosity in a population caused by subpopulation structure (Koertvelyessy et al 1988). This statistic is calculated by the formula:…”

“…For this reason, surname distributions can be used for inferring genetic structure, admixture, genetic drift, and estimates of the intensity and directionality of human migrations (Darlu et al 2012;Koertvelyessy et al 1988;Lasker 1985;Rodríguez-Larralde et al 2011). Non-random or assortative mating in human populations can result in surname stratification or subdivision while geographic isolation, conflicts, religion, and other cultural behaviors can contribute to their spatial distribution (Fix 1999;Koertvelyessy et al 1988;North and Crawford 1996). Isonymic models have been applied to wide ranging studies covering small groups, such as those found in households and villages, to large populations representing entire countries or even continents (Colantonio et al 2003;Darlu et al 2012).…”

“…Ideally, isonymic models assume that surnames have monophyletic origins and are transmitted from parents to biological children, simulating neutral alleles (Colantonio et al 2003;Lasker 1991). For this reason, surname distributions can be used for inferring genetic structure, admixture, genetic drift, and estimates of the intensity and directionality of human migrations (Darlu et al 2012;Koertvelyessy et al 1988;Lasker 1985;Rodríguez-Larralde et al 2011). Non-random or assortative mating in human populations can result in surname stratification or subdivision while geographic isolation, conflicts, religion, and other cultural behaviors can contribute to their spatial distribution (Fix 1999;Koertvelyessy et al 1988;North and Crawford 1996).…”

Effects of religion, economics, and geography on genetic structure of Fogo Island, Newfoundland

“…Tilting is the only all Irish Catholic community and is the most endogamous (Koertvelyessy et al, 1988). Although reproductive isolation due to religious affiliation is diminishing, the decline in endogamy rates among the Catholics of Fog0 is significantly less than among the Protestant groups.…”

“…The unique history of Newfoundland offers a n opportunity to examine the interactions of migration, geography, religion, and economic factors on the observed genetic variation in fishing villages. Koertvelyessy et al (1988), using the repeated-pairs approach (RP), documented a n excess of observed over random surname repetitions, most likely a result of religious subdivisions of Fog0 Island.…”