Epidemic cycles in agricultural populations: a cross-cultural study.

A cross-cultural analysis of mortality patterns is of interest to biological anthropologists and genetic epidemiologists. In this paper, we examine four agricultural populations from Costa Rica, Hungary, and the United States in order to determine if they suffered from a cyclical distribution of epidemics. When possible, we look at the mortality time series of adults and children separately. Of the 2 series, only 2 show significant epidemic cycles. Both are in the Hungarian groups and both affect subadults. Otherwise, the Costa Rica, U.S., and adult series of the Hungarian groups do not show any periodicity of mortality peaks. Our results indicate that epidemic cycles are not as ubiquitous in small agricultural groups as the literature would suggest.

The population structure of ten Newfoundland outports.

Island populations are most informative in the study of the genetic structure of human aggregates. These populations are often of small size, thus violating the Hardy-Weinberg assumption of infinite size. Some geographically isolated island populations are further subdivided by religion, ethnicity, and socioeconomic factors, reducing their effective sizes and facilitating genetic changes due to stochastic processes. Because of extreme geographic and social isolation, fishing communities or outports of Newfoundland have been investigated for genetic microdifferentiation through the founder effect and genetic drift (Crawford et al. 1995). The purpose of this paper is to examine the population structure of 10 Newfoundland outports using the allelic frequencies derived from 12 red cell antigens. To achieve this goal, first we calculated gene frequencies using maximum-likelihood estimation procedures. Second, we used R-matrix methods to explore population differentiation. Third, we regressed mean per-locus heterozygosity on genetic distance from the gene frequency centroid to identify the most isolated populations. On the basis of this information, the three outports of Seal Cove, Island Harbor, and Tilting were found to be genetically differentiated from the other small populations. Moreover, religious and geographic subdivisions appear to explain the observed genetic variation.

The influence of religious affiliation on surname repetition in marriages in Tiszaszalka, Hungary.

The repeated-pairs of surnames in marriages (RP) approach is applied to the population of Tiszaszalka in north-eastern Hungary. The results indicate that: (1) lineage-like behaviour in mate choice results in population subdivision in both the Catholics and the Protestants of the village; (2) unlike in some other Tiszahat villages, the isonymous and the repeating unions in Tiszaszalka occur in different lineages so, in neither of these subpopulations are isonymous and repeating unions monopolised by a few lineages; (3) religious affilitation influences the mating structure of the population as measured by RP summary scores.

PIP: Matrix methods have been devised to overcome the limitation of the isonomy method with high sampling errors. The repeated pairs (RP) of surnames in marriages approach proposed by Lasker and Kaplan in 1985 measures the effect of lineage in mate choice. Any excess of RP over the random occurrence (RP1) indicates lineage involvement via surnames. The degree of population subdivision from lineage influence on mate choice was estimated, lineage influence on repeating matings and isonomy was analyzed, and the effect of religion on mate choice in repeating and isonymous unions was explored. Marriage records were obtained in 1986 in Tiszaszalka and from the Genealogical Society in Salt Lake City, Utah (from 1806 for Protestants and from 1936 for Catholics). 1271 first marriages were analyzed: 972 Protestants and 299 Catholics. The RP and RP1 were larger among the Protestants than among the Catholics. The chi-square value for unique and nonunique surname pairs for the 2 religions was statistically significant: for total Protestant vs. incomplete Catholic and for partial Protestant vs. incomplete Catholic. The distribution of Isonymous and nonisonymous marriages of both religions was not significant indicating no inbreeding. After excluding isonymous matings the chi-square values for unique and nonunique surname pairs remained significant for both religious groups. The coefficient of isonomy indicated that both groups avoided isonymous unions since 1936, thus inbreeding was insignificant. In both groups lineage like behavior in mate choice resulted in population subdivision; religion influenced mating structure significantly and genetic variability decreased as a result. The incidence of isonomy was also low in several other villages in the region, and the RP approaches focus on husband's and wife's surnames was valuable regarding marriage patterns and genetic variability.

Surname repetition and isonymy in northeastern Hungarian marriages.

The repeated-pair (RP) approach to surnames in married couples is a measure of population subdivision resulting from the influence of lineagelike behavior in mate choice. An excess of RP over random RP implies limitations in mate choice and a reduction of genetic variability. Here we apply the RP method to data from the rural populations of Csaroda, Tiszaadony, and Tiszavid in northeastern Hungary. The results indicate small differences between RP and random RP for Tiszavid and somewhat larger differences for Tiszaadony and Csaroda. The excess of RP over random RP in Tiszavid, however, derives primarily from marriages simultaneously isonymous and repeating in only one lineage. The discrepancy between RP and random RP implies a small reduction in genetic variability.

Marital structure and genetic heterogeneity of Ramea Island, Newfoundland.

The population structure of Ramea Island, Newfoundland, is described using surname, marital migration, and serological data. Results presented indicate that Ramea is an open and heterogeneous population. It is shown, however, that this contemporary characterization has a time depth of only three decades and has resulted from a rapid population response to a single historical/economic event.