Search results for "COALESCENT"
showing 3 items of 43 documents
Bayesian estimation of partial population continuity using ancient DNA and spatially explicit simulations.
2017
Abstract The retrieval of ancient DNA from osteological material provides direct evidence of human genetic diversity in the past. Ancient DNA samples are often used to investigate whether there was population continuity in the settlement history of an area. Methods based on the serial coalescent algorithm have been developed to test whether the population continuity hypothesis can be statistically rejected by analysing DNA samples from the same region but of different ages. Rejection of this hypothesis is indicative of a large genetic shift, possibly due to immigration occurring between two sampling times. However, this approach is only able to reject a model of full continuity model (a tot…
A multi-gene approach reveals a complex evolutionary history in the Cyanistes species group
2011
Quaternary climatic oscillations have been considered decisive in shaping much of the phylogeographic structure around the Mediterranean Basin. Within this paradigm, peripheral islands are usually considered as the endpoints of the colonization processes. Here, we use nuclear and mitochondrial markers to investigate the phylogeography of the blue tit complex (blue tit Cyanistes caeruleus, Canary blue tit C. teneriffae and azure tit C. cyanus), and assess the role of the Canary Islands for the geographic structuring of genetic variation. The Canary blue tit exhibits strong genetic differentiation within the Canary Islands and, in combination with other related continental species, provides a…
Molecular epidemiology of HIV-1 subtype B in the Basque Country (Spain)
2012
The goal of this work was to study the HIV-1 subtype B epidemic in the Basque Country (Spain). For this, we used HIV samples submitted for genotypic testing of anti-retroviral resistance mutations from 2005 until 2008. Consequently, 2115 HIV-1 sequences comprising protease and retrotranscriptase (PR/RT) coding regions were analyzed. HIV transmission groups were identified by phylogenetic analysis. The 10 largest such groups were subsequently subjected to Bayesian phylogenetic and coalescent reconstructions, using a relaxed molecular clock model. The results obtained show that these groups have been long-standing: most of them were originated in the late 70s or early 80s, and none after the …