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Population differentiation of Southern Indian male lineages correlates with agricultural expansions predating the caste system

2013-05-20T04:43:09Z

Title: Population differentiation of Southern Indian male lineages correlates with agricultural expansions predating the caste system Author: ArunKumar, GaneshPrasad; ... et al.; Genographic Consortium Abstract: Previous studies that pooled Indian populations from a wide variety of geographical locations, have obtained contradictory conclusions about the processes of the establishment of the Varna caste system and its genetic impact on the origins and demographic histories of Indian populations. To further investigate these questions we took advantage that both Y chromosome and caste designation are paternally inherited, and genotyped 1,680 Y chromosomes representing 12 tribal and 19 non-tribal (caste) endogamous populations from the predominantly Dravidian-speaking Tamil Nadu state in the southernmost part of India. Tribes and castes were both characterized by an overwhelming proportion of putatively Indian autochthonous Y-chromosomal haplogroups (H-M69, F-M89, R1a1-M17, L1-M27, R2-M124, and C5-M356; 81% combined) with a shared genetic heritage dating back to the late Pleistocene (10–30 Kya), suggesting that more recent Holocene migrations from western Eurasia contributed, <20% of the male lineages. We found strong evidence for genetic structure, associated primarily with the current mode of subsistence. Coalescence analysis suggested that the social stratification was established 4–6 Kya and there was little admixture during the last 3 Kya, implying a minimal genetic impact of the Varna(caste) system from the historically-documented Brahmin migrations into the area. In contrast, the overall Y-chromosomal patterns, the time depth of population diversifications and the period of differentiation were best explained by the emergence of agricultural technology in South Asia. These results highlight the utility of detailed local genetic studies within India, without prior assumptions about the importance of Varna rank status for population grouping, to obtain new insights into the relative influences of past demographic events for the population structure of the whole of modern India. Description: Christina J. Adler, Alan Cooper, Clio S.I. Der Sarkissian and Wolfgang Haak are contributors to the Genographic Consortium

Land use changes imperil South-East Asian biodiversity

2013-04-10T05:31:05Z

Title: Land use changes imperil South-East Asian biodiversity Author: Sodhi, Navjot Singh; Posa, Mary Rose C.; Peh, Kelvin S-H.; Koh, Lian Pin; Soh, Malcolm C. K.; Lee, Tien Ming; Lee, Janice S. H.; Wanger, Thomas Cherico; Brook, Barry W.

Last chance to see: the role of phylogeography in the preservation of tropical biodiversity

2013-04-24T02:12:08Z

Title: Last chance to see: the role of phylogeography in the preservation of tropical biodiversity Author: Macqueen, Peggy Ellen Abstract: Habitat loss and anthropogenic climate change are primary threats to global biological diversity and ecosystem stability. International efforts to halt the effects of climate change and to slow the loss of biodiversity are now focused on the tropical biome. Specifically, and in recognition of the substantial contribution to climate warming made by deforestation in developing countries, the UN-REDD+ programme has been established to provide incentives for stopping tropical deforestation. This programme also places emphasis on rewarding measures for the conservation of biodiversity. However, the effective integration of carbon storage and biodiversity conservation goals in countries participating in the REDD+ programme will require greater research effort. In particular, in order to maximize our chances of preserving biological diversity, it will be essential to consider diversity at a population level, as well as at a species and ecosystem level. Phylogeographic studies should be an integral part of this population-level research effort as they can be used to document regional biological diversity, provide baseline genetic data to monitor changes in genetic diversity, allow the identification of evolutionary refugia, and provide evolutionary context for current patterns of diversity. The REDD+ initiative has the potential to provide an internationally well-supported framework for reducing forest habitat loss and protecting tropical diversity, and may, therefore, provide the impetus needed for increased biodiversity research effort. In conjunction with the recent development of the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES), phylogeographic research may now be considered more explicitly in the development of national environmental policies and in planning for biodiversity conservation.

A lost link between a flightless parrot and a parasitic plant and the potential role of coprolites in conservation paleobiology

2013-03-25T02:30:11Z

Title: A lost link between a flightless parrot and a parasitic plant and the potential role of coprolites in conservation paleobiology Author: Wood, Jamie Russell; Wilmshurst, Janet Mary; Worthy, Trevor Henry; Holzapfel, Avi S.; Cooper, Alan