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An informative set of biallelic polymorphisms was used to study the structure of Y-chromosome variability in a sample from the Mediterranean islands of Corsica and Sicily, and compared with data on Sardinia to gain insights into the ethnogenesis of these island populations. The results were interpreted in a broader Mediterranean context by including in the analysis neighboring populations previously studied with the same methodology. All samples studied were enclosed in the comparable spectrum of European Y-chromosome variability. Pronounced differences were observed between the islands as well as in the percentages of haplotypes previously shown to have distinctive patterns of continental phylogeography. Approximately 60% of the Sicilian haplotypes are also prevalent in Southern Italy and Greece. Conversely, the Corsican sample had elevated levels of alternative haplotypes common in Northern Italy. Sardinia showed a haplotype ratio similar to that observed in Corsica, but with a remarkable difference in the presence of a lineage defined by marker M26, which approaches 35% in Sardinia but seems absent in Corsica. Although geographically adjacent, the data suggest different colonization histories and a minimal amount of recent gene flow between them. Our results identify possible ancestral continental sources of the various island populations and underscore the influence of founder effect and genetic drill The Y-chromosome data are consistent with comparable mtDNA data at the RFLP haplogroup level of resolution, as well as linguistic and historic knowledge. KEY WORDS Y-chromosome; population genetics; Mediterranean populations

Cultural inheritance can be considered as a mechanism of adaptation made possible by communication, which has reached its greatest development in humans and can allow long-term conservation or rapid change of culturally transmissible traits depending on circumstances and needs. Conservativeness/flexibility is largely modulated by mechanisms of sociocultural transmission. An analysis was carried out by testing the fit of three models to 47 cultural traits (classified in six groups) in 277 African societies. Model A (demic diffusion) is conservation over generations, as shown by correlations of cultural traits with language, used as a measure of historical connection. Model B (environmental adaptation) is measured by correlation to the natural environment. Model C (cultural diffusion) is the spread to neighbors by social contact in an epidemic-like fashion and was tested by measuring the tightness of geographic clustering of the traits. Most traits examined, in particular those affecting family structure and kinship, showed great conservation over generations, as shown by the fit of model A. They are most probably transmitted by family members. This is in agreement with the theoretical demonstration that cultural transmission in the family (vertical) is the most conservative one. Some traits show environmental effects, indicating the importance of adaptation to physical environment. Only a few of the 47 traits showed tight geographic clustering indicating that their spread to nearest neighbors follows model C, as is usually the case for transmission among unrelated people (called horizontal transmission).

A new method of genetic dating supports the out-of-Africa theory of human evolution. Using 30 microsatellite polymorphisms and the average mutation rate as 5.6 multiplied by 10 to the -4th power, researchers estimated the split in the African and the non-African human populations to be 156,000 years ago. A calibrated mutation rate based on archaeological data estimates the time to be about 130,000 years ago.

Analysis of nuclear DNA restriction polymorphisms, obtained from various extant human samples, helps study human evolution and the relationship between humans and primates. These polymorphisms reveal that alleles, isolated from humans belonging to eight different populations, are similar to those found in chimpanzees. The presence of identical alleles in two or more species characterized polymorphism.

The comparison of an evolutionary tree of a set of global human populations constructed from genetic data to a linguistic classification tree shows sufficient similarities to suggest the coevolution of languages and genes. However, this apparent correlation must be supported by statistical tests. The Monte Carlo approach was used to test the correlation between linguistic and genetic evolutionary history. The results showed that the correlation between the two histories are stronger than 10(super -3), suggesting a signifiant relationship. Possible explanations for the coevolution of genetic and cultural characters are discussed.

Wilson's disease is a disorder of copper metabolism. The gene for Wilson's disease is especially common, and about 1 in 90 of all people carry this gene. Wilson's disease is recessive: the disease results when an individual inherits one of the disease genes from each of his or her parents. The gene for Wilson's disease is located on chromosome 13. Using the techniques of molecular biology, it is now possible to locate the gene within the chromosome with great precision. In the past, researchers could identify the location of a gene only when nearby genetic markers were available for correlation. Now it is possible to use DNA fragments to examine regions of chromosomes where classic markers are few and far between. Studying 52 families affected by Wilson's disease in North America, Europe, and the Middle East, it was possible to determine that the most likely location for the Wilson's disease gene was between two DNA markers on the long arm of chromosome 13, near q14. A larger number of families will have to be studied before the definitive assignment can be made. A clinically important result of this finding is that it may be possible to determine the likelihood of Wilson's disease in children who have not yet begun to develop symptoms. It should be emphasized that a true screening test has not been accomplished, but rather that the odds for a particular child in a family with a history of Wilson's disease may be calculated. For some genetic disorders, such a determination may be of only academic interest. But Wilson's disease may be treated with penicillamine, which binds excess copper that has accumulated and helps the body eliminate it. Therefore, the identification of children with the disorder prior to the development of symptoms may result in the early initiation of treatment with improved results. (Consumer Summary produced by Reliance Medical Information, Inc.)

We have analysed data of three European populations speaking non-Indoeuropean languages: Hungarians, Lapps, and Finns. Principal coordinate analysis shows that Lapps are almost exactly intermediate between people located geographically near the Ural mountains and speaking Uralic languages, and central and northern Europeans. Hungarians and Finns are definitely closer to Europeans. An analysis of genetic admixture between Uralic and European ancestors shows that Lapps are slightly more than 50% European, Hungarians are 87% European, and Finns are 90% European. There is basic agreement between these conclusions and historical data on Hungary. Less is known about Finns and very little about Lapps.

The construction of human evolutionary trees incorporating polymorphic microsatellite details enables the understanding of evolutionary relations. This approach is applicable only to human populations and not among ape species possibly due to allele length variation constraints. The microsatellite diversity, unlike other nuclear markers, is highest in Africa, thus reinforcing the possible African origin for humans.