We conclude that although these linguistically related populations in geographic proximity demonstrate a high degree of paternal genetic differentiation, recent demographic events have dramatically altered the paternal genetic structure of the regions Amerindian populations.

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, ...

The Rama are a coastal population from southern Nicaragua who in large part were able to resist, at least for a time, the cultural changes and social reorganization brought on by colonial and modern influences. Historical information leaves the Rama origins and biological relationships with nearby extinct and extant groups ambiguous. The objective of this study was to examine the internal genetic microdifferentiation based on the first hypervariable region of the mitochondrial DNA (mtDNA) from a sample of approximately 20% of the population, and to expand the few available historical and anthropological data on the Rama by exploring the effects of cultural practices and historical events on genetic structure, providing an integrative perspective on the Rama genetic history. When considering differences in the spatial distribution and genetic diversity of the mtDNA haplotypes together with historical information on the Rama, a noteworthy pattern emerges. (a) Haplotypes are differentially distributed among a central Rama community (Punta Águila) compared with the other five peripheral communities (analysis of molecular variance: F CT = 0.10, p < 0.001), and their distribution is consistent with the historical relocation of this population after their split from Punta Gorda in the 18th century. (b) Differential genetic signatures found among central and peripheral Rama communities resemble two population histories: one of stability (haplogroup A2) and other of expansion (haplogroup B2), supporting the possibility that these patterns of genetic microdifferentiation between central and peripheral populations resulted from the 18th-century unification in southern Nicaragua of the Rama and a group of Voto migrants from Costa Rica that later split off and moved to the Bay of Bluefields.

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Cover sheet Cover sheetTitle Effect of recent historical events on migration and isonymic stratification among the Rama Amerindians from Nicaragua