| 1. |
- Bergström, Anders, et al.
(författare)
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Grey wolf genomic history reveals a dual ancestry of dogs
- 2022
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 607:7918, s. 313-320
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Tidskriftsartikel (refereegranskat)abstract
- The grey wolf (Canis lupus) was the first species to give rise to a domestic population, and they remained widespread throughout the last Ice Age when many other large mammal species went extinct. Little is known, however, about the history and possible extinction of past wolf populations or when and where the wolf progenitors of the present-day dog lineage (Canis familiaris) lived. Here we analysed 72 ancient wolf genomes spanning the last 100,000 years from Europe, Siberia and North America. We found that wolf populations were highly connected throughout the Late Pleistocene, with levels of differentiation an order of magnitude lower than they are today. This population connectivity allowed us to detect natural selection across the time series, including rapid fixation of mutations in the gene IFT88 40,000–30,000 years ago. We show that dogs are overall more closely related to ancient wolves from eastern Eurasia than to those from western Eurasia, suggesting a domestication process in the east. However, we also found that dogs in the Near East and Africa derive up to half of their ancestry from a distinct population related to modern southwest Eurasian wolves, reflecting either an independent domestication process or admixture from local wolves. None of the analysed ancient wolf genomes is a direct match for either of these dog ancestries, meaning that the exact progenitor populations remain to be located.
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| 2. |
- Cappellini, Enrico, et al.
(författare)
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Early Pleistocene enamel proteome from Dmanisi resolves Stephanorhinus phylogeny
- 2019
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 574:7776, s. 103-
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Tidskriftsartikel (refereegranskat)abstract
- The sequencing of ancient DNA has enabled the reconstruction of speciation, migration and admixture events for extinct taxa(1). However, the irreversible post-mortem degradation(2) of ancient DNA has so far limited its recovery-outside permafrost areasto specimens that are not older than approximately 0.5 million years (Myr)(3). By contrast, tandem mass spectrometry has enabled the sequencing of approximately 1.5-Myr-old collagen type I-4. and suggested the presence of protein residues in fossils of the Cretaceous period(5)-although with limited phylogenetic use(6). In the absence of molecular evidence, the speciation of several extinct species of the Early and Middle Pleistocene epoch remains contentious. Here we address the phylogenetic relationships of the Eurasian Rhinocerotidae of the Pleistocene epoch(7-9), using the proteome of dental enamel from a Stephanorhinus tooth that is approximately 1.77-Myr old, recovered from the archaeological site of Dmanisi (South Caucasus, Georgia)(10). Molecular phylogenetic analyses place this Stephanorhinus as a sister group to the Glade formed by the woolly rhinoceros (Coelodonta antiquitatis) and Merck's rhinoceros (Stephanorhinus kirchbergensis). We show that Coelodonta evolved from an early Stephanorhinus lineage, and that this latter genus includes at least two distinct evolutionary lines. The genus Stephanorhinus is therefore currently paraphyletic, and its systematic revision is needed. We demonstrate that sequencing the proteome of Early Pleistocene dental enamel overcomes the limitations of phylogenetic inference based on ancient collagen or DNA. Our approach also provides additional information about the sex and taxonomic assignment of other specimens from Dmanisi. Our findings reveal that proteomic investigation of ancient dental enamel-which is the hardest tissue in vertebrates(11), and is highly abundant in the fossil record-can push the reconstruction of molecular evolution further back into the Early Pleistocene epoch, beyond the currently known limits of ancient DNA preservation.
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| 3. |
- Dalen, Love, et al.
(författare)
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Partial Genetic Turnover in Neandertals : Continuity in the East and Population Replacement in the West
- 2012
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Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 29:8, s. 1893-1897
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Tidskriftsartikel (refereegranskat)abstract
- Remarkably little is known about the population-level processes leading up to the extinction of the neandertal. To examine this, we use mitochondrial DNA sequences from 13 neandertal individuals, including a novel sequence from northern Spain, to examine neandertal demographic history. Our analyses indicate that recent western European neandertals (< 48 kyr) constitute a tightly defined group with low mitochondrial genetic variation in comparison with both eastern and older (> 48 kyr) European neandertals. Using control region sequences, Bayesian demographic simulations provide higher support for a model of population fragmentation followed by separate demographic trajectories in subpopulations over a null model of a single stable population. The most parsimonious explanation for these results is that of a population turnover in western Europe during early Marine Isotope Stage 3, predating the arrival of anatomically modern humans in the region.
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| 4. |
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| 5. |
- Ersmark, Erik, et al.
(författare)
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Population demography and genetic diversity in the Pleistocene cave lion
- 2015
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Ingår i: Open Quaternary. - : Ubiquity Press, Ltd.. - 2055-298X. ; 1:1
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Tidskriftsartikel (refereegranskat)abstract
- With a range that covered most of northern Eurasia and parts of North America, the cave lion (Panthera spelaea) was one of the most widespread carnivores of the Late Pleistocene. Earlier ancient DNA analyses have shown that it is distinct from modern lions, and have suggested a demographic decline in Beringia during marine isotope stage 3 (MIS 3). Here, we further investigate the Late Pleistocene population dynamics in more detail by combining a powerful algorithm that couples MCMC with coalescent simulations under an approximate Bayesian computation framework. We use an ancient DNA dataset of previously published (n = 34) and new radiocarbon dated specimens (n = 14). Phylogenetic and network analyses based on the mitochondrial control region and the ATP8 gene identified two major haplogroups, one of which appears to vanish around 41,000 cal a BP. The approximate Bayesian computation analysis suggested a decline in effective population size (Ne) in Beringia of at least a 2-fold magnitude that began approximately 47,000 cal a BP, followed by an increase in Ne, most likely around 18,000 cal a BP. The cave lion went through a demographic bottleneck during MIS 3, which may have lasted for several tens of thousands of years, and only recovered shortly before the species' extinction. Several other large mammal species display similar declines in genetic diversity in Beringia during MIS 3, suggesting that major environmental changes might have affected megafaunal populations during this time period.
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| 6. |
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| 7. |
- Liu, Shiping, et al.
(författare)
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Population Genomics Reveal Recent Speciation and Rapid Evolutionary Adaptation in Polar Bears
- 2014
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Ingår i: Cell. - : Elsevier BV. - 0092-8674 .- 1097-4172. ; 157:4, s. 785-794
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Tidskriftsartikel (refereegranskat)abstract
- Polar bears are uniquely adapted to life in the High Arctic and have undergone drastic physiological changes in response to Arctic climates and a hyper-lipid diet of primarily marine mammal prey. We analyzed 89 complete genomes of polar bear and brown bear using population genomic modeling and show that the species diverged only 479-343 thousand years BP. We find that genes on the polar bear lineage have been under stronger positive selection than in brown bears; nine of the top 16 genes under strong positive selection are associated with cardiomyopathy and vascular disease, implying important reorganization of the cardiovascular system. One of the genes showing the strongest evidence of selection, APOB, encodes the primary lipoprotein component of low-density lipoprotein (LDL); functional mutations in APOB may explain how polar bears are able to cope with life-long elevated LDL levels that are associated with high risk of heart disease in humans.
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| 8. |
- Sarkissian, Clio Der, et al.
(författare)
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Unveiling the Ecological Applications of Ancient DNA From Mollusk Shells
- 2020
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Ingår i: Frontiers in Ecology and Evolution. - : Frontiers Media SA. - 2296-701X. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The shells of marine mollusks represent promising metagenomic archives of the past, adding to bones, teeth, hairs, and environmental samples most commonly examined in ancient DNA research. Seminal work has established that DNA recovery from marine mollusk shells depends on their microstructure, preservation and disease state, and that authentic ancient DNA could be retrieved from specimens as old as 7,000 years. Here, we significantly push the temporal limit for shell DNA recovery to >= 100,000 years with the successful genetic characterization of one Portlandia arctica and one Mytilus mussel sample collected within a dated permafrost layer from the Taimyr Peninsula, Russia. We expand the analysis of ancient DNA in carbonate shells to a larger number of genera (Arctica, Cernuella, Crassostrea, Dreissena, Haliotis, Lymnaea, Margaritifera, Pecten, Ruditapes, Venerupis) from marine, freshwater and terrestrial environments. We demonstrate that DNA from ancient shells can provide sufficient resolution for taxonomic, phylogenetic and/or population assignment. Our results confirm mollusk shells as long-term DNA reservoirs, opening new avenues for the investigation of environmental changes, commercial species management, biological invasion, and extinction. This is especially timely in light of modern threats to biodiversity and ecosystems.
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