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1.
The surfperch genus Embiotoca currently comprises two species, Embiotoca jacksoni , the black surfperch, and Embiotoca lateralis , the striped surfperch. Originally, however, Louis Agassiz described a third species in the genus Embiotoca , the rainbow surfperch, Embiotoca caryi . This latter name was changed by Louis' son, Alexander, to Hypsurus caryi , a name that remains valid. In this study, new molecular data (3545 bp of DNA from four mitochondrial and two nuclear DNA regions) indicated that the rainbow surfperch should be retained within the genus Embiotoca , a result consistent with recent morphological data. Adaptive radiation combined with sexual selection resulting in rapid morphological changes in the rainbow surfperch may have contributed to the conflicting position of this species.  相似文献   

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Understanding the basis of specificity in an intermolecular interaction is a common if difficult task; designing a specific intermolecular interaction is much more challenging. A new technique is described that has applications to both problems, at least with regard to nucleic acids. The power of this method lies in its ability to isolate extremely rare sequences with precisely specified properties from very large pools of random sequences.  相似文献   

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It has widely been recognized that the media play a key role in framing debates about genetic issues. This paper provides an overview of the major areas of debate within the social scientific literature on media, public understanding of science and human genetics. It evaluates current approaches to assessing the role of the media in influencing public policy debates. It argues that an analysis of the strategies of news sources should occupy a central role in furthering understanding about the ways in which various social actors seek to influence public policy agendas. At present, within the field of human genetics, only a handful of researchers have systematically examined the strategies of news sources from the perspective of the sources themselves. While recent research has focused upon identifying the major sources and how they are used in science reporting, there remains much to be done in uncovering the processes of negotiation and contestation among social actors prior to issues gaining media coverage.  相似文献   

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The population of Easter Island is one of the most interesting extant human communities due to its unique demographic history, its geographic isolation, and the development of an incomparable culture characterized by the towering "Moais" and its enigmatic writing. Following the colonization of its population by Polynesians from the Mangarevan Islands in the 5th century AD, the island remained isolated up until the middle of the 20th century. Under these conditions, with endogamy levels fluctuating between 61.04-96.54% and given such a small population, a high rate of inbreeding, and consequently, an elevated level of genetic relationships would be expected. Using data from church and civil records, we calculated the consanguinity of the population of Rapa Nui. The results of this analysis do not support the hypothesis of a high level of consanguinity (alpha = 0.00028 and F(t) = 0.0007, with F(r) = 0.00586 and F(n) = -0.00519), suggesting instead the existence of a strategy used to avoid marriage between close relatives. To explain these observations, the structure and exchange dynamics of the population were studied in the tribes, known locally as "Mata." The results of this analysis suggest a tendency toward the avoidance of inbreeding within tribes, in order to decrease the rate of endogamy in each group. This is consistent with ethnographic observations from the beginning of the 20th century that support the existence of strict regulations to prevent inbreeding between closely related individuals. Furthermore, we confirm that this situation dates back to a period before the "refounding" of Easter Island. Our results demonstrate that conditions of geographical isolation are not in themselves sufficient to produce an elevated inbreeding coefficient, revealing Easter Island as an interesting example of how cultural rules can shape the genetic structure of a population.  相似文献   

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Surnames are cultural markers of shared ancestry within human populations. The Y chromosome, like many surnames, is paternally inherited, so men sharing surnames might be expected to share similar Y chromosomes as a signature of coancestry. Such a relationship could be used to connect branches of family trees, to validate population genetic studies based on isonymy, and to predict surname from crime-scene samples in forensics. However, the link may be weak or absent due to multiple independent founders for many names, adoptions, name changes and nonpaternities, and mutation of Y haplotypes. Here, rather than focusing on a single name, we take a general approach by seeking evidence for a link in a sample of 150 randomly ascertained pairs of males who each share a British surname. We show that sharing a surname significantly elevates the probability of sharing a Y-chromosomal haplotype and that this probability increases as surname frequency decreases. Within our sample, we estimate that up to 24% of pairs share recent ancestry and that a large surname-based forensic database might contribute to the intelligence-led investigation of up to approximately 70 rapes and murders per year in the UK. This approach would be applicable to any society that uses patrilineal surnames of reasonable time-depth.  相似文献   

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To study the genetic variability of the HLA loci A, B, DR, and DQ in the Netherlands, we analyzed more than 13,000 typings provided by the Dutch National Reference Laboratory for Histocompatibility. To investigate any possibly existing population structure, we subdivided the typings by the geographic location of residency of donors and by the historical belonging of their surnames to given provinces. Concerning possible geographic patterns, we found no significant differences between the four provinces examined (North Holland, South Holland, Utrecht, Zeeland). To assess whether such a negative result was related to recent immigration to the area (the richest of the country) that erased possible preexisting patterns of HLA diversity, we reprocessed the database according to the surnames of HLA donors. We obtained two groups: (1) those having a surname typical of the four provinces they inhabit and (2) those with surnames coming from elsewhere. Such an analysis was made possible because of the availability of a database concerning the geographic origin of most Dutch surnames. Even with this surname-based approach, no major differences were found. We conclude that either the western part of the Netherlands was genetically homogeneous before the official introduction of Dutch surnames two centuries ago by Napoleon or surnames have no power in dissecting HLA variability; that is, such variability is the result of recombination phenomena that surnames cannot mirror because they are transmitted virtually unchanged generation after generation. A comparable study by other investigators recommended the use of family names to identify rare HLA haplotypes in France, but now, concerning the Netherlands, we find opposite results. We suggest that a few typing centers may be sufficient to type bone marrow donors, because HLA genetic differences between the different provinces of the Netherlands are extremely low. To maximize the number of donors, such centers should be located in areas providing the easiest access to the largest population of possible donors, thus disregarding the search for a local variability that we did not find.  相似文献   

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The evolution of surnames: an analysis of their distribution and extinction   总被引:6,自引:0,他引:6  
Surname distribution and evolution can be analyzed by a theory put forward for neutral mutation by Karlin and McGregor. This theory allows us to predict the distribution of surnames, and to predict immigration on the basis of knowledge of population size, and of the total number of different surnames or, in lieu of the latter, a quantity known as random isonymy.Another approach allows us to predict probabilities of extinction after any number of generations and various sets of conditions. The predictions of these theories have been tested successfully on a number of empirical data from the Upper Parma Valley.  相似文献   

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Surnames are traditionally used in population genetics as "quasi-genetic" markers (i.e., analogs of genes) when studying the structure of the gene pool and the factors of its microevolution. In this study, spatial variation of Russian surnames was analyzed with the use of computer-based gene geography. Gene geography of surnames was demonstrated to be promising for population studies on the total Russian gene pool. Frequencies of surnames were studied in 64 sel'sovets (rural communities; a total of 33 thousand persons) of 52 raions (districts) of 22 oblasts (regions) of the European part of Russia. For each of 75 widespread surnames, an electronic map of its frequency was constructed. Summary maps of principal components were drawn based on all maps of individual surnames. The first 5 of 75 principal components accounted for half of the total variance, which indicates high resolving power of surnames. The map of the first principal component exhibits a trend directed from the northwestern to the eastern regions of the area studied. The trend of the second component was directed from the southwestern to the northern regions of the area studied, i.e., it was close to latitudinal. This trend almost coincided with the latitudinal trend of principal components for three sets of data (genetic, anthropological, and dermatoglyphical). Therefore, the latitudinal trend may be considered the main direction of variation of the Russian gene pool. The similarity between the main scenarios for the genetic and quasi-genetic markers demonstrates the effectiveness of the use of surnames for analysis of the Russian gene pool. In view of the dispute between R. Sokal and L.L. Cavalli-Sforza about the effects of false correlations, the maps of principal components of Russian surnames were constructed by two methods: through analysis of maps and through direct analysis of original data on the frequencies of surnames. An almost complete coincidence of these maps (correlation coefficient rho = 0.96) indicates that, taking into account the reliability of the data, the resultant maps of principal components have no errors of false correlations.  相似文献   

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McEvoy B  Bradley DG 《Human genetics》2006,119(1-2):212-219
Ireland has one of the oldest systems of patrilineal hereditary surnames in the world. Using the paternal co-inheritance of Y-chromosome DNA and Irish surnames, we examined the extent to which modern surname groups share a common male-line ancestor and the general applicability of Y-chromosomes in uncovering surname origins and histories. DNA samples were collected from 1,125 men, bearing 43 different surnames, and each was genotyped for 17 Y-chromosome short tandem repeat (STR) loci. A highly significant proportion of the observed Y-chromosome diversity was found between surnames demonstrating their demarcation of real and recent patrilineal kinship. On average, a man has a 30-fold increased chance of sharing a 17 STR Y-chromosome haplotype with another man of the same surname but the extent of congruence between the surname and haplotype varies widely between surnames and we attributed this to differences in the number of early founders. Some surnames such as O’Sullivan and Ryan have a single major ancestor, whereas others like Murphy and Kelly have numerous founders probably explaining their high frequency today. Notwithstanding differences in their early origins, all surnames have been extensively affected by later male introgession. None examined showed more than about half of current bearers still descended from one original founder indicating dynamic and continuously evolving kinship groupings. Precisely because of this otherwise cryptic complexity there is a substantial role for the Y-chromosome and a molecular genealogical approach to complement and expand existing sources.  相似文献   

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Surnames of grandparents were collected from children in the primary schools of the Albanian-Italian, Croat-Italian and Greek-Italian villages of southern Italy and Sicily. The coefficients of relationships by isonymy show almost no relationship with ethnicity. Ethnolinguistic minorities of southern Italy and Sicily are geographically subdivided into two main clusters: the first cluster comprises the Albanian, Croat and Greek communities of the Adriatic area; and the second cluster comprises the Albanian and Greek communities of the Ionian, Thirrenian and Sicilian areas.  相似文献   

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As a part of a wider analysis of population and genetic exchange between Spain and Portugal, the long-term pattern of Portuguese immigration to the Canary Islands was studied by means of the frequency of Portuguese surnames. A database of 1,995,833 individuals was obtained from the Spanish National Statistics Institute (2006). Among the 826 most frequent surnames to appear, 79 surnames of Portuguese origin were selected. The distribution of these surnames by municipalities and islands, the Fisher index of diversity, and the Lasker inter-population relationship coefficients R(ij) were considered. These coefficients were inter-correlated and correlated with other variables that could have influenced the distribution of surnames. From the observed distribution of the frequency of surnames, a non-random migration pattern conditioned by economic factors was found. The greatest diversity of surnames existed in cane cultivating areas after the first arrival of Portuguese immigrants. A later dispersion of surnames among islands was correlated with the inter-island geographic distances. In some islands the arrival of new immigrants continued due to their strategic location within the Canary archipelago. The Canary Islands reveal a high frequency and diversity of Portuguese surnames. The results also prove a heterogeneous distribution of these surnames throughout the archipelago. In contrast to the Portuguese archipelagos, some Canary localities have received immigrants continuously because of their economic importance in sugar cane cultivation and strategic geographic location on the maritime routes to Africa and America.  相似文献   

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The following study compares the distribution of surnames in the populations of Western Slovenian municipalities, which were part of the Italian state until the end of the Second World War. The analyses have been carried out firstly by assessing the similarity of different populations to one another so as to verify possible aggregations; secondly, by figuring these relationships of similarity in a representation through unrooted tree (NJ); finally, by applying spatial autocorrelation to the distribution of surnames in the territory so as to highlight possible processes in the diffusion of people in the area under examination. On the whole, it seems likely that the population living in the area is geographically quite stable, although some differences may be noted depending both on the geography of the territory, particularly in the northern part, and on peculiar historical and socioeconomic conditions, which at the same time have characterized and modified the demographic structure of some of these municipalities.  相似文献   

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