| 1. |
- Gilbert, T., et al.
(författare)
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DNA from Pre-Clovis Human Coprolites in Oregon, North America
- 2008
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 320:5877, s. 786-789
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Tidskriftsartikel (refereegranskat)abstract
- The timing of the first human migration into the Americas and its relation to the appearance of the Clovis technological complex in North America at about 11,000 to 10,800 radiocarbon years before the present ( C-14 years B. P.) remains contentious. We establish that humans were present at Paisley 5 Mile Point Caves, in south- central Oregon, by 12,300 C-14 years B. P., through the recovery of human mitochondrial DNA ( mtDNA) from coprolites, directly dated by accelerator mass spectrometry. The mtDNA corresponds to Native American founding haplogroups A2 and B2. The dates of the coprolites are > 1000 C-14 years earlier than currently accepted dates for the Clovis complex.
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| 2. |
- Valdiosera, C., et al.
(författare)
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Surprising migration and population size dynamics in ancient Iberian brown bears (Ursus arctos)
- 2008
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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. ; 105:13, s. 5123-5128
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Tidskriftsartikel (refereegranskat)abstract
- The endangered brown bear populations (Ursus arctos) in Iberia have been suggested to be the last fragments of the brown bear population that served as recolonization stock for large parts of Europe during the Pleistocene. Conservation efforts are intense, and results are closely monitored. However, the efforts are based on the assumption that the Iberian bears are a unique unit that has evolved locally for an extended period. We have sequenced mitochondrial DNA (mtDNA) from ancient Iberian bear remains and analyzed them as a serial clataset, monitoring changes in diversity and occurrence of European haplogroups over time. Using these data, we show that the Iberian bear population has experienced a dynamic, recent evolutionary history. Not only has the population undergone mitochondrial gene flow from other European brown bears, but the effective population size also has fluctuated substantially. We conclude that the Iberian bear population has been a fluid evolutionary unit, developed by gene flow from other populations and population bottlenecks, far from being in genetic equilibrium or isolated from other brown bear populations. Thus, the current situation is highly unusual and the population may in fact be isolated for the first time in its history.
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| 3. |
- Leonard, JA, et al.
(författare)
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Ancient DNA : From individuals to populations
- 2006
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Ingår i: Molecular Markers, PCR, Bioinformatics and Ancient DNA. - : Science Publishers, New York.
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 4. |
- Willerslev, Eske, et al.
(författare)
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Ancient biomolecules from deep ice cores reveal a forested Southern Greenland
- 2007
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 317:5834, s. 111-114
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Tidskriftsartikel (refereegranskat)abstract
- It is difficult to obtain fossil data from the 10% of Earth's terrestrial surface that is covered by thick glaciers and ice sheets, and hence, knowledge of the paleoenvironments of these regions has remained limited. We show that DNA and amino acids from buried organisms can be recovered from the basal sections of deep ice cores, enabling reconstructions of past flora and fauna. We show that high-altitude southern Greenland, currently lying below more than 2 kilometers of ice, was inhabited by a diverse array of conifer trees and insects within the past million years. The results provide direct evidence in support of a forested southern Greenland and suggest that many deep ice cores may contain genetic records of paleoenvironments in their basal sections.
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