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Genetic and linguistic coevolution in Northern Island Melanesia.

Hunley K, Dunn M, Lindström E, Reesink G, Terrill A, Healy ME, Koki G, Friedlaender FR, Friedlaender JS - PLoS Genet. (2008)

Bottom Line: There we found some of the strongest recorded correlations between genetic, linguistic, and geographic distances.We also found that, throughout the region, linguistic features have generally been less likely to diffuse across population boundaries than genes.The results from our study, based on exceptionally fine-grained data, show that local genetic and linguistic exchange are likely to obscure evidence of the early history of a region, and that language barriers do not particularly hinder genetic exchange.

View Article: PubMed Central - PubMed

Affiliation: Department of Anthropology, University of New Mexico, Albuquerque, NM, USA. khunley@unm.edu

ABSTRACT
Recent studies have detailed a remarkable degree of genetic and linguistic diversity in Northern Island Melanesia. Here we utilize that diversity to examine two models of genetic and linguistic coevolution. The first model predicts that genetic and linguistic correspondences formed following population splits and isolation at the time of early range expansions into the region. The second is analogous to the genetic model of isolation by distance, and it predicts that genetic and linguistic correspondences formed through continuing genetic and linguistic exchange between neighboring populations. We tested the predictions of the two models by comparing observed and simulated patterns of genetic variation, genetic and linguistic trees, and matrices of genetic, linguistic, and geographic distances. The data consist of 751 autosomal microsatellites and 108 structural linguistic features collected from 33 Northern Island Melanesian populations. The results of the tests indicate that linguistic and genetic exchange have erased any evidence of a splitting and isolation process that might have occurred early in the settlement history of the region. The correlation patterns are also inconsistent with the predictions of the isolation by distance coevolutionary process in the larger Northern Island Melanesian region, but there is strong evidence for the process in the rugged interior of the largest island in the region (New Britain). There we found some of the strongest recorded correlations between genetic, linguistic, and geographic distances. We also found that, throughout the region, linguistic features have generally been less likely to diffuse across population boundaries than genes. The results from our study, based on exceptionally fine-grained data, show that local genetic and linguistic exchange are likely to obscure evidence of the early history of a region, and that language barriers do not particularly hinder genetic exchange. In contrast, global patterns may emphasize more ancient demographic events, including population splits associated with the early colonization of major world regions.

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Related in: MedlinePlus

Simulated and observed heat plots for the branching model.The heat plots are color-coded representations of the square matrix of within- and between-population allelic identities. The level of allelic identity is indicated by the color-scale at the bottom of each plot. The diagonals represent the within population allelic identities, and the off-diagonals represent the between-population identities. Population names are located above and to the left of the matrix. The Oceanic-speaking populations are shaded in gray. (A,B) The populations are clustered first by language group, then by island. (B) The circled population groupings have high allelic identity even though the populations are in different language groups. (C) The populations are clustered only by island and neighborhood.
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pgen-1000239-g003: Simulated and observed heat plots for the branching model.The heat plots are color-coded representations of the square matrix of within- and between-population allelic identities. The level of allelic identity is indicated by the color-scale at the bottom of each plot. The diagonals represent the within population allelic identities, and the off-diagonals represent the between-population identities. Population names are located above and to the left of the matrix. The Oceanic-speaking populations are shaded in gray. (A,B) The populations are clustered first by language group, then by island. (B) The circled population groupings have high allelic identity even though the populations are in different language groups. (C) The populations are clustered only by island and neighborhood.

Mentions: As mentioned, Figure 2 shows the presumed history of population splits used as the basis for the simulated branching model. Figure 3A shows the simulated heat plot derived from the simulations of this branching history. The simulated allelic identities in Figure 3A are lowest between the Oceanic and Papuan populations, higher between populations on different islands, higher still between populations within islands, and highest within populations. The level of allelic identity is also uniform between populations at different levels in the hierarchy, reflecting the isolation of branches following ancient population splits. The hierarchical organization and the uniformity of allelic identity within major clusters are fundamental properties of the branching process.


Genetic and linguistic coevolution in Northern Island Melanesia.

Hunley K, Dunn M, Lindström E, Reesink G, Terrill A, Healy ME, Koki G, Friedlaender FR, Friedlaender JS - PLoS Genet. (2008)

Simulated and observed heat plots for the branching model.The heat plots are color-coded representations of the square matrix of within- and between-population allelic identities. The level of allelic identity is indicated by the color-scale at the bottom of each plot. The diagonals represent the within population allelic identities, and the off-diagonals represent the between-population identities. Population names are located above and to the left of the matrix. The Oceanic-speaking populations are shaded in gray. (A,B) The populations are clustered first by language group, then by island. (B) The circled population groupings have high allelic identity even though the populations are in different language groups. (C) The populations are clustered only by island and neighborhood.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2570610&req=5

pgen-1000239-g003: Simulated and observed heat plots for the branching model.The heat plots are color-coded representations of the square matrix of within- and between-population allelic identities. The level of allelic identity is indicated by the color-scale at the bottom of each plot. The diagonals represent the within population allelic identities, and the off-diagonals represent the between-population identities. Population names are located above and to the left of the matrix. The Oceanic-speaking populations are shaded in gray. (A,B) The populations are clustered first by language group, then by island. (B) The circled population groupings have high allelic identity even though the populations are in different language groups. (C) The populations are clustered only by island and neighborhood.
Mentions: As mentioned, Figure 2 shows the presumed history of population splits used as the basis for the simulated branching model. Figure 3A shows the simulated heat plot derived from the simulations of this branching history. The simulated allelic identities in Figure 3A are lowest between the Oceanic and Papuan populations, higher between populations on different islands, higher still between populations within islands, and highest within populations. The level of allelic identity is also uniform between populations at different levels in the hierarchy, reflecting the isolation of branches following ancient population splits. The hierarchical organization and the uniformity of allelic identity within major clusters are fundamental properties of the branching process.

Bottom Line: There we found some of the strongest recorded correlations between genetic, linguistic, and geographic distances.We also found that, throughout the region, linguistic features have generally been less likely to diffuse across population boundaries than genes.The results from our study, based on exceptionally fine-grained data, show that local genetic and linguistic exchange are likely to obscure evidence of the early history of a region, and that language barriers do not particularly hinder genetic exchange.

View Article: PubMed Central - PubMed

Affiliation: Department of Anthropology, University of New Mexico, Albuquerque, NM, USA. khunley@unm.edu

ABSTRACT
Recent studies have detailed a remarkable degree of genetic and linguistic diversity in Northern Island Melanesia. Here we utilize that diversity to examine two models of genetic and linguistic coevolution. The first model predicts that genetic and linguistic correspondences formed following population splits and isolation at the time of early range expansions into the region. The second is analogous to the genetic model of isolation by distance, and it predicts that genetic and linguistic correspondences formed through continuing genetic and linguistic exchange between neighboring populations. We tested the predictions of the two models by comparing observed and simulated patterns of genetic variation, genetic and linguistic trees, and matrices of genetic, linguistic, and geographic distances. The data consist of 751 autosomal microsatellites and 108 structural linguistic features collected from 33 Northern Island Melanesian populations. The results of the tests indicate that linguistic and genetic exchange have erased any evidence of a splitting and isolation process that might have occurred early in the settlement history of the region. The correlation patterns are also inconsistent with the predictions of the isolation by distance coevolutionary process in the larger Northern Island Melanesian region, but there is strong evidence for the process in the rugged interior of the largest island in the region (New Britain). There we found some of the strongest recorded correlations between genetic, linguistic, and geographic distances. We also found that, throughout the region, linguistic features have generally been less likely to diffuse across population boundaries than genes. The results from our study, based on exceptionally fine-grained data, show that local genetic and linguistic exchange are likely to obscure evidence of the early history of a region, and that language barriers do not particularly hinder genetic exchange. In contrast, global patterns may emphasize more ancient demographic events, including population splits associated with the early colonization of major world regions.

Show MeSH
Related in: MedlinePlus