PubMed · 11634664
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
E Cayón Armella. 1983. [Not Available].. https://pubmed.ncbi.nlm.nih.gov/11634664/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
We report a comparative genetic characterization of two population isolates with parallel demographic histories: the Central Valley of Costa Rica (CVCR) and Antioquia (in northwest Colombia). The analysis of mtDNA, Y-chromosome and autosomal polymorphisms shows that Antioquia and the CVCR are genetically very similar, indicating that closely related parental populations founded these two isolates. In both populations, the male ancestry is predominantly European, whereas the female ancestry is mostly Amerind. In agreement with their isolation, the Amerindian mtDNA diversity of Antioquia and the CVCR is typical of ethnically-defined native populations and is markedly lower than in other Latin American populations. A comparison of linkage disequilibrium (LD) at 18 marker pairs in Antioquia and the CVCR shows that markers in LD in both populations are located at short genetic distances (<approximately 1 cM), whereas markers separated by greater distances are in LD only in the CVCR. This difference probably reflects stochastic variation of LD at the limited number of genome regions compared. The genetic similarity of the populations from Antioquia and the CVCR together with differences in LD between them should be exploitable for the identification and fine mapping of shared disease-related gene variants.
Explore the source record for details and available documents.
The distribution of plant species, the species compositions of different sites, and the factors that affect them in tropical rain forests are not well understood. The main hypotheses are that species composition is either (i) uniform over large areas, (ii) random but spatially autocorrelated because of dispersal limitation, or (iii) patchy and environmentally determined. Here we test these hypotheses, using a large data set from western Amazonia. The uniformity hypothesis gains no support, but the other hypotheses do. Environmental determinism explains a larger proportion of the variation in floristic differences between sites than does dispersal limitation; together, these processes explain 70 to 75% of the variation. Consequently, it is important that management planning for conservation and resource use take into account both habitat heterogeneity and biogeographic differences.