TY - JOUR A1 - Casas-Marce, Mireia A1 - Marmesat, Elena A1 - Soriano, Laura A1 - Martinez-Cruz, Begona A1 - Lucena-Perez, Maria A1 - Nocete, Francisco A1 - Rodriguez-Hidalgo, Antonio A1 - Canals, Antoni A1 - Nadal, Jordi A1 - Detry, Cleia A1 - Bernaldez-Sanchez, Eloisa A1 - Fernandez-Rodriguez, Carlos A1 - Perez-Ripoll, Manuel A1 - Stiller, Mathias A1 - Hofreiter, Michael A1 - Rodriguez, Alejandro A1 - Revilla, Eloy A1 - Delibes, Miguel A1 - Godoy, Jose A. T1 - Spatiotemporal Dynamics of Genetic Variation in the Iberian Lynx along Its Path to Extinction Reconstructed with Ancient DNA JF - Molecular biology and evolution N2 - There is the tendency to assume that endangered species have been both genetically and demographically healthier in the past, so that any genetic erosion observed today was caused by their recent decline. The Iberian lynx (Lynx pardinus) suffered a dramatic and continuous decline during the 20th century, and now shows extremely low genome- and species-wide genetic diversity among other signs of genomic erosion. We analyze ancient (N = 10), historical (N = 245), and contemporary (N = 172) samples with microsatellite and mitogenome data to reconstruct the species' demography and investigate patterns of genetic variation across space and time. Iberian lynx populations transitioned from low but significantly higher genetic diversity than today and shallow geographical differentiation millennia ago, through a structured metapopulation with varying levels of diversity during the last centuries, to two extremely genetically depauperate and differentiated remnant populations by 2002. The historical subpopulations show varying extents of genetic drift in relation to their recent size and time in isolation, but these do not predict whether the populations persisted or went finally extinct. In conclusion, current genetic patterns were mainly shaped by genetic drift, supporting the current admixture of the two genetic pools and calling for a comprehensive genetic management of the ongoing conservation program. This study illustrates how a retrospective analysis of demographic and genetic patterns of endangered species can shed light onto their evolutionary history and this, in turn, can inform conservation actions. KW - Iberian lynx KW - ancient DNA KW - paleogenetics KW - genetic erosion KW - endangered species Y1 - 2017 U6 - https://doi.org/10.1093/molbev/msx222 SN - 0737-4038 SN - 1537-1719 VL - 34 SP - 2893 EP - 2907 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Alberti, Federica A1 - Gonzalez, Javier A1 - Paijmans, Johanna L. A. A1 - Basler, Nikolas A1 - Preick, Michaela A1 - Henneberger, Kirstin A1 - Trinks, Alexandra A1 - Rabeder, Gernot A1 - Conard, Nicholas J. A1 - Muenzel, Susanne C. A1 - Joger, Ulrich A1 - Fritsch, Guido A1 - Hildebrandt, Thomas A1 - Hofreiter, Michael A1 - Barlow, Axel T1 - Optimized DNA sampling of ancient bones using Computed Tomography scans JF - Molecular ecology resources N2 - The prevalence of contaminant microbial DNA in ancient bone samples represents the principal limiting factor for palaeogenomic studies, as it may comprise more than 99% of DNA molecules obtained. Efforts to exclude or reduce this contaminant fraction have been numerous but also variable in their success. Here, we present a simple but highly effective method to increase the relative proportion of endogenous molecules obtained from ancient bones. Using computed tomography (CT) scanning, we identify the densest region of a bone as optimal for sampling. This approach accurately identifies the densest internal regions of petrous bones, which are known to be a source of high-purity ancient DNA. For ancient long bones, CT scans reveal a high-density outermost layer, which has been routinely removed and discarded prior to DNA extraction. For almost all long bones investigated, we find that targeted sampling of this outermost layer provides an increase in endogenous DNA content over that obtained from softer, trabecular bone. This targeted sampling can produce as much as 50-fold increase in the proportion of endogenous DNA, providing a directly proportional reduction in sequencing costs for shotgun sequencing experiments. The observed increases in endogenous DNA proportion are not associated with any reduction in absolute endogenous molecule recovery. Although sampling the outermost layer can result in higher levels of human contamination, some bones were found to have more contamination associated with the internal bone structures. Our method is highly consistent, reproducible and applicable across a wide range of bone types, ages and species. We predict that this discovery will greatly extend the potential to study ancient populations and species in the genomics era. KW - ancient DNA KW - computer tomography KW - palaeogenomics KW - paleogenetics KW - petrous bone Y1 - 2018 U6 - https://doi.org/10.1111/1755-0998.12911 SN - 1755-098X SN - 1755-0998 VL - 18 IS - 6 SP - 1196 EP - 1208 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Almathen, Faisal A1 - Charruau, Pauline A1 - Mohandesan, Elmira A1 - Mwacharo, Joram M. A1 - Orozco-terWengel, Pablo A1 - Pitt, Daniel A1 - Abdussamad, Abdussamad M. A1 - Uerpmann, Margarethe A1 - Uerpmann, Hans-Peter A1 - De Cupere, Bea A1 - Magee, Peter A1 - Alnaqeeb, Majed A. A1 - Salim, Bashir A1 - Raziq, Abdul A1 - Dessie, Tadelle A1 - Abdelhadi, Omer M. A1 - Banabazi, Mohammad H. A1 - Al-Eknah, Marzook A1 - Walzer, Chris A1 - Fayer, Bernard A1 - Hofreiter, Michael A1 - Peters, Joris A1 - Hanotte, Olivier A1 - Burger, Pamela A. T1 - Ancient and modern DNA reveal dynamics of domestication and cross-continental dispersal of the dromedary JF - Proceedings of the National Academy of Sciences of the United States of America N2 - Dromedaries have been fundamental to the development of human societies in arid landscapes and for long-distance trade across hostile hot terrains for 3,000 y. Today they continue to be an important livestock resource in marginal agro-ecological zones. However, the history of dromedary domestication and the influence of ancient trading networks on their genetic structure have remained elusive. We combined ancient DNA sequences of wild and early-domesticated dromedary samples from arid regions with nuclear microsatellite and mitochondrial genotype information from 1,083 extant animals collected across the species’ range. We observe little phylogeographic signal in the modern population, indicative of extensive gene flow and virtually affecting all regions except East Africa, where dromedary populations have remained relatively isolated. In agreement with archaeological findings, we identify wild dromedaries from the southeast Arabian Peninsula among the founders of the domestic dromedary gene pool. Approximate Bayesian computations further support the “restocking from the wild” hypothesis, with an initial domestication followed by introgression from individuals from wild, now-extinct populations. Compared with other livestock, which show a long history of gene flow with their wild ancestors, we find a high initial diversity relative to the native distribution of the wild ancestor on the Arabian Peninsula and to the brief coexistence of early-domesticated and wild individuals. This study also demonstrates the potential to retrieve ancient DNA sequences from osseous remains excavated in hot and dry desert environments. KW - anthropogenic admixture KW - Camelus dromedarius KW - demographic history KW - paleogenetics KW - wild dromedary Y1 - 2016 U6 - https://doi.org/10.1073/pnas.1519508113 SN - 0027-8424 VL - 113 SP - 6707 EP - 6712 PB - National Acad. of Sciences CY - Washington ER -