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

Abstract

This study's objective was to discern the degree of relatedness between and within subdivisions of seven of these communities based on patterns of surname variation and genealogical data. We applied surname analyses (n= 592) to evaluate inter-and intrapopulation variation, consanguinity and substructure estimates and isolation by distance, and used a genealogically based marital (Conzemius 1927;Lehmann 1920;Loveland 1975;Roberts 1978Roberts [1827; Romero 1996). They subsisted on horticulture, hunting, and fishing, continually moving across their territory in small family units to exploit a variety of microenvironments based on seasonality. Group mobility allowed them to avoid the coast and migrate up river to more interior localities, effectively shielding them from flooding, hurricanes, and the outbreak of infectious diseases associated with climatologic events ( Despite changes to the traditional Rama subsistence strategy, group mobility, and land access, field researchers from this study (P.M. and N.B.) recently documented domestic networks connecting communities to their home base across many kilometers (Baldi 2013).Given that these communities are relatively recent phenomena which have not previously been investigated, this study seeks to ascertain the degree of relatedness between and within subdivisions of seven Rama communities based on geographical patterns of surname variation and genealogical data. In order to evaluate surname variation and population subdivisions, it is assumed that the distribution of marital surnames tends to deviate from panmixia due to geographic distance and sociocultural factors. In theory, non-random mating will also have an effect on gene frequencies (Barrai et al. 2002). Deviation from panmixia can be indirectly assessed through the use of methods based on isonymy, or the study and analysis of recurring surnames within a given pedigree (Lasker 1969). 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). 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).The integration of genealogical information with genetic studies has recently been recognized as an important source of information on mutational, ...

Population History and Mitochondrial Genetic Substructure of the Rama Amerindians from Nicaragua

“…To these samples, we added 75 additional samples collected by Melton et al (2013) (total n = 265). Details on geographical locations and general information on each Rama community visited during fieldwork are summarized in Baldi et al (2014).…”

“…AMOVA was calculated based on geographical and kin affiliation criteria (Baldi et al 2014) using pairwise genetic differences. The R-matrix analysis was performed in ANTANA (Harpending and Rogers 1984) and displayed as a principal component analysis (PCA) plot using HVS-I mtDNA sequence data.…”

“…The gene flow between individuals of African and European ancestry was probably recent (Battistuzzi et al 1986), and it is more frequent at Rama Cay, Punta Águila, and Greytown than in any other Rama community according to admixture estimations obtained from previous surname analysis and a recent demographic survey (Baldi et al 2014;Gobierno Territorial Rama y Kriol 2007).…”

“…Recent studies in anthropological genetics and historical linguistics suggest that the Rama are related to other Chibchan speakers from SCA and northern South America (Constenla 2008;Melton et al 2013) and were significantly impacted by paternal gene flow from Europeans (Melton et al 2013). These investigations, however, have not integrated historical factors for better understanding the causes of the Rama's internal microdifferentiation that was detected by a previous study based on isonymy and genealogies (Baldi et al 2014). The present study examined the level of population microdifferentiation, based on the analysis of the first hypervariable segment (HVS-I) of mitochondrial DNA (mtDNA) of six Rama subpopulations in the southern Caribbean region of Nicaragua.…”

“…The second AMOVA divides northern (Sumu Kat, Rama Cay, and Zompopera), central (Punta Águila), and southern Rama localities (Indian River and Greytown). The third AMOVA tested two groups based on kinship relationships previously proposed by Baldi et al (2014); Punta Águila differentiated from the remaining five localities of the Rama territory. Table 5 presents the results of the first AMOVA based on the separation of eastern-western and northern-southern localities and shows significant differentiation among these groupings (F CT = 0.10183, p < 0.001).…”