| 1. |
- Karmin, Monika, et al.
(författare)
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A recent bottleneck of Y chromosome diversity coincides with a global change in culture.
- 2015
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051 .- 1549-5469. ; 25:4
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Tidskriftsartikel (refereegranskat)abstract
- It is commonly thought that human genetic diversity in non-African populations was shaped primarily by an out-of-Africa dispersal 50-100 thousand yr ago (kya). Here, we present a study of 456 geographically diverse high-coverage Y chromosome sequences, including 299 newly reported samples. Applying ancient DNA calibration, we date the Y-chromosomal most recent common ancestor (MRCA) in Africa at 254 (95% CI 192-307) kya and detect a cluster of major non-African founder haplogroups in a narrow time interval at 47-52 kya, consistent with a rapid initial colonization model of Eurasia and Oceania after the out-of-Africa bottleneck. In contrast to demographic reconstructions based on mtDNA, we infer a second strong bottleneck in Y-chromosome lineages dating to the last 10 ky. We hypothesize that this bottleneck is caused by cultural changes affecting variance of reproductive success among males.
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| 2. |
- Lorenzen, Eline D., et al.
(författare)
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Species-specific responses of Late Quaternary megafauna to climate and humans
- 2011
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 479:7373, s. 359-364
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Tidskriftsartikel (refereegranskat)abstract
- Despite decades of research, the roles of climate and humans in driving the dramatic extinctions of large-bodied mammals during the Late Quaternary period remain contentious. Here we use ancient DNA, species distribution models and the human fossil record to elucidate how climate and humans shaped the demographic history of woolly rhinoceros, woolly mammoth, wild horse, reindeer, bison and musk ox. We show that climate has been a major driver of population change over the past 50,000 years. However, each species responds differently to the effects of climatic shifts, habitat redistribution and human encroachment. Although climate change alone can explain the extinction of some species, such as Eurasian musk ox and woolly rhinoceros, a combination of climatic and anthropogenic effects appears to be responsible for the extinction of others, including Eurasian steppe bison and wild horse. We find no genetic signature or any distinctive range dynamics distinguishing extinct from surviving species, emphasizing the challenges associated with predicting future responses of extant mammals to climate and human-mediated habitat change.
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| 3. |
- Alves, Isabel, et al.
(författare)
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Human genetic structure in Northwest France provides new insights into West European historical demography
- 2024
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- The demographical history of France remains largely understudied despite its central role toward understanding modern population structure across Western Europe. Here, by exploring publicly available Europe-wide genotype datasets together with the genomes of 3234 present-day and six newly sequenced medieval individuals from Northern France, we found extensive fine-scale population structure across Brittany and the downstream Loire basin and increased population differentiation between the northern and southern sides of the river Loire, associated with higher proportions of steppe vs. Neolithic-related ancestry. We also found increased allele sharing between individuals from Western Brittany and those associated with the Bell Beaker complex. Our results emphasise the need for investigating local populations to better understand the distribution of rare (putatively deleterious) variants across space and the importance of common genetic legacy in understanding the sharing of disease-related alleles between Brittany and people from western Britain and Ireland.
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| 4. |
- Anderung, Cecilia, 1972-
(författare)
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Genetic Analyses of Bovid Remains and the Origin of Early European Cattle
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aurochs Bos primigenius, extinct since 1627, was the wild progenitor of cattle. It is believed that all European cattle originate from one domestication event in the Near East 10 000 years ago. However, it is evident from the archaeological record that the aurochs survived into historic time and spent many years existing alongside domestic cattle. Thus, a question posed is whether aurochsen were locally domesticated or incorporated into early domestic cattle stock.In this thesis, genetic techniques are applied to ancient and modern DNA from bovids in order to study questions relating to the origin of early European cattle. DNA from ancient specimens is fragmented and in greatly reduced quantity. Therefore mitochondrial DNA, present in many copies in the living cell, has long been dominating the ancient DNA research field. Analyses of ancient DNA presented in this work are based on both mitochondrial DNA and nuclear DNA, through the study of Single Nuclear Polymorohism (SNPs). A method for typing ancient SNPs was developed and applied to ancient cattle bones.Mitochondrial DNA of cattle is structured into five geographically distributed lineages, the dominant lineage in Europe is also found in the Near East where additional lineages are found. This pattern has been attributed to the proposed domestication event in the Near East from where cattle carrying the single lineage were brought to Europe. However, the results presented here show that cattle domestication was more complicated than previously suggested. SNP data from extant cattle and bones from cattle and aurochs point towards a hybridisation event. European cattle appear indeed to have been domesticated in the Near East and brought in to the European continent from there. However, once in Europe, hybridisation with local aurochsen took place. It appears therefore that today’s cattle descend both from both Anatolian and European aurochsen.
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| 5. |
- Axelsson, Erik, et al.
(författare)
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The effect of ancient DNA damage on inferences of demographic histories.
- 2008
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Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 25:10, s. 2181-7
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Tidskriftsartikel (refereegranskat)abstract
- The field of ancient DNA (aDNA) is casting new light on many evolutionary questions. However, problems associated with the postmortem instability of DNA may complicate the interpretation of aDNA data. For example, in population genetic studies, the inclusion of damaged DNA may inflate estimates of diversity. In this paper, we examine the effect of DNA damage on population genetic estimates of ancestral population size. We simulate data using standard coalescent simulations that include postmortem damage and show that estimates of effective population sizes are inflated around, or right after, the sampling time of the ancestral DNA sequences. This bias leads to estimates of increasing, and then decreasing, population sizes, as observed in several recently published studies. We reanalyze a recently published data set of DNA sequences from the Bison (Bison bison/Bison priscus) and show that the signal for a change in effective population size in this data set vanishes once the effects of putative damage are removed. Our results suggest that population genetic analyses of aDNA sequences, which do not accurately account for damage, should be interpreted with great caution.
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| 6. |
- Bærholm Schnell, Ida, et al.
(författare)
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Characterisation of insect and plant origins using DNA extracted from small volumes of bee honey
- 2010
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Ingår i: Arthropod-Plant Interactions. - Dordrecht : Springer Science+Business Media B.V.. - 1872-8855 .- 1872-8847. ; 4:2, s. 107-116
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Tidskriftsartikel (refereegranskat)abstract
- A DNA-based tool was validated that potentially enables the characterisation of both plant and insect of origin of small (approximately 1 ml) samples of bee honey. Using this method, mitochondrial, nuclear and chloroplast DNA (mtDNA, nuDNA, cpDNA) markers were successfully extracted, PCR amplified, and sequenced from a range of honeys, and the relative amount of plant nuDNA and cpDNA, and bee mtDNA in the samples was quantified using quantitative real-time PCR.Short, but taxonomically informative lengths of insect and plant organelle DNA could be routinely recovered from all honey samples tested, and longer organelle, and nuclear DNA sequences can be recovered from many. The data also enabled preliminary characterisation of the quality of these different DNA sources in honey. Although the absolute quantity of the different genetic markers varied considerably between sample, a general trend was observed of insect mtDNA dominating over plant organelle DNA, and with plant nuclear DNA at the lowest levels. Furthermore there was a clear correlation between the plant DNA content and the success of the PCR assays. To maximise successful characterisation of samples, future studies are recommended to focus on the use of organelle markers, and limit the size of PCR amplicons targeted, although with appropriate sample selection and assay optimisation, other approaches may be possible.
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| 7. |
- Campos, Paula F, et al.
(författare)
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Ancient DNA analyses exclude humans as the driving force behind late Pleistocene musk ox (Ovibos moschatus) population dynamics
- 2010
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 107:12, s. 5675-5680
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Tidskriftsartikel (refereegranskat)abstract
- The causes of the late Pleistocene megafaunal extinctions are poorly understood. Different lines of evidence point to climate change, the arrival of humans, or a combination of these events as the trigger. Although many species went extinct, others, such as caribou and bison, survived to the present. The musk ox has an intermediate story: relatively abundant during the Pleistocene, it is now restricted to Greenland and the Arctic Archipelago. In this study, we use ancient DNA sequences, temporally unbiased summary statistics, and Bayesian analytical techniques to infer musk ox population dynamics throughout the late Pleistocene and Holocene. Our results reveal that musk ox genetic diversity was much higher during the Pleistocene than at present, and has undergone several expansions and contractions over the past 60,000 years. Northeast Siberia was of key importance, as it was the geographic origin of all samples studied and held a large diverse population until local extinction at approximately 45,000 radiocarbon years before present ((14)C YBP). Subsequently, musk ox genetic diversity reincreased at ca. 30,000 (14)C YBP, recontracted at ca. 18,000 (14)C YBP, and finally recovered in the middle Holocene. The arrival of humans into relevant areas of the musk ox range did not affect their mitochondrial diversity, and both musk ox and humans expanded into Greenland concomitantly. Thus, their population dynamics are better explained by a nonanthropogenic cause (for example, environmental change), a hypothesis supported by historic observations on the sensitivity of the species to both climatic warming and fluctuations.
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| 8. |
- Campos, Paula F., et al.
(författare)
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Ancient DNA sequences point to a large loss of mitochondrial genetic diversity in the saiga antelope (Saiga tatarica) since the Pleistocene
- 2010
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Ingår i: Molecular Ecology. - 0962-1083 .- 1365-294X. ; 19:22, s. 4863-4875
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Tidskriftsartikel (refereegranskat)abstract
- Prior to the Holocene, the range of the saiga antelope (Saiga tatarica) spanned from France to the Northwest Territories of Canada. Although its distribution subsequently contracted to the steppes of Central Asia, historical records indicate that it remained extremely abundant until the end of the Soviet Union, after which its populations were reduced by over 95%. We have analysed the mitochondrial control region sequence variation of 27 ancient and 38 modern specimens, to assay how the species' genetic diversity has changed since the Pleistocene. Phylogenetic analyses reveal the existence of two well-supported, and clearly distinct, clades of saiga. The first, spanning a time range from >49 500 C-14 ybp to the present, comprises all the modern specimens and ancient samples from the Northern Urals, Middle Urals and Northeast Yakutia. The second clade is exclusive to the Northern Urals and includes samples dating from between 40 400 to 10 250 C-14 ybp. Current genetic diversity is much lower than that present during the Pleistocene, an observation that data modelling using serial coalescent indicates cannot be explained by genetic drift in a population of constant size. Approximate Bayesian Computation analyses show the observed data is more compatible with a drastic population size reduction (c. 66-77%) following either a demographic bottleneck in the course of the Holocene or late Pleistocene, or a geographic fragmentation (followed by local extinction of one subpopulation) at the Holocene/Pleistocene transition.
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| 9. |
- Capo, Eric, et al.
(författare)
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Lake sedimentary dna research on past terrestrial and aquatic biodiversity: Overview and recommendations
- 2021
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Ingår i: Quaternary. - : MDPI. - 2571-550X. ; 4:1
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Forskningsöversikt (refereegranskat)abstract
- The use of lake sedimentary DNA to track the long-term changes in both terrestrial and aquatic biota is a rapidly advancing field in paleoecological research. Although largely applied nowadays, knowledge gaps remain in this field and there is therefore still research to be conducted to ensure the reliability of the sedimentary DNA signal. Building on the most recent literature and seven original case studies, we synthesize the state-of-the-art analytical procedures for effective sampling, extraction, amplification, quantification and/or generation of DNA inventories from sedimentary ancient DNA (sedaDNA) via high-throughput sequencing technologies. We provide recommendations based on current knowledge and best practises.
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| 10. |
- Clemente, Florian J, et al.
(författare)
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A Selective Sweep on a Deleterious Mutation in CPT1A in Arctic Populations.
- 2014
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Ingår i: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297 .- 1537-6605. ; 95:5
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Tidskriftsartikel (refereegranskat)abstract
- Arctic populations live in an environment characterized by extreme cold and the absence of plant foods for much of the year and are likely to have undergone genetic adaptations to these environmental conditions in the time they have been living there. Genome-wide selection scans based on genotype data from native Siberians have previously highlighted a 3 Mb chromosome 11 region containing 79 protein-coding genes as the strongest candidates for positive selection in Northeast Siberians. However, it was not possible to determine which of the genes might be driving the selection signal. Here, using whole-genome high-coverage sequence data, we identified the most likely causative variant as a nonsynonymous G>A transition (rs80356779; c.1436C>T [p.Pro479Leu] on the reverse strand) in CPT1A, a key regulator of mitochondrial long-chain fatty-acid oxidation. Remarkably, the derived allele is associated with hypoketotic hypoglycemia and high infant mortality yet occurs at high frequency in Canadian and Greenland Inuits and was also found at 68% frequency in our Northeast Siberian sample. We provide evidence of one of the strongest selective sweeps reported in humans; this sweep has driven this variant to high frequency in circum-Arctic populations within the last 6-23 ka despite associated deleterious consequences, possibly as a result of the selective advantage it originally provided to either a high-fat diet or a cold environment.
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