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MtDNA analysis of global populations support that major population expansions began before Neolithic Time.

Zheng HX, Yan S, Qin ZD, Jin L - Sci Rep (2012)

Bottom Line: With the benefit of 1000 Genome Project, we were able to analyze a total of 910 samples from 11 populations in Africa, Europe and Americas.Furthermore, major population expansions were estimated after Last Glacial Maximum but before Neolithic Time, also corresponding to the result of major lineage expansions.Considering results in current and previous study, global mtDNA evidence showed that rising temperature after Last Glacial Maximum offered amiable environments and might be the most important factor for prehistorical human expansions.

View Article: PubMed Central - PubMed

Affiliation: MOE Key Laboratory of Contemporary Anthropology and Center for Evolutionary Biology, School of Life Sciences and Institutes of Biomedical Sciences, Fudan University, Shanghai, China.

ABSTRACT
Agriculture resulted in extensive population growths and human activities. However, whether major human expansions started after Neolithic Time still remained controversial. With the benefit of 1000 Genome Project, we were able to analyze a total of 910 samples from 11 populations in Africa, Europe and Americas. From these random samples, we identified the expansion lineages and reconstructed the historical demographic variations. In all the three continents, we found that most major lineage expansions (11 out of 15 star lineages in Africa, all autochthonous lineages in Europe and America) coalesced before the first appearance of agriculture. Furthermore, major population expansions were estimated after Last Glacial Maximum but before Neolithic Time, also corresponding to the result of major lineage expansions. Considering results in current and previous study, global mtDNA evidence showed that rising temperature after Last Glacial Maximum offered amiable environments and might be the most important factor for prehistorical human expansions.

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Related in: MedlinePlus

American expansion lineages from median-joining network.Star expansions were selected from median-joining network of 184 Ameican mtDNA coding region sequences corresponding to rCRS positions 577–16023.Blue, CLM; yellow, MXL; Green, PUR. Red squares and numbers indicate clusters with distinct expansions. 1, A2; 2, A2w; 3, B2; 4, B2d; 5, C1; 6, D1. Branch length is proportional to steps of mutations and red arrows indicate the root.
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f6: American expansion lineages from median-joining network.Star expansions were selected from median-joining network of 184 Ameican mtDNA coding region sequences corresponding to rCRS positions 577–16023.Blue, CLM; yellow, MXL; Green, PUR. Red squares and numbers indicate clusters with distinct expansions. 1, A2; 2, A2w; 3, B2; 4, B2d; 5, C1; 6, D1. Branch length is proportional to steps of mutations and red arrows indicate the root.

Mentions: For Native Americans, we observed six expansions of lineages, of which four (A2, B2, C1 and D1) were shared by different populations. The four lineages were also the main constitutions and founding lineages in American gene pool303132. The remaining 2 lineages, B2d and A2w were CLM-specific (see Figure 6). As expected, we found some African L lineages and European N lineages which might be admixed from recent contacts with immigrants. For example, in MXL, African component (U6) was about 3% and European component (H, V and W) was about 12% (Table S4), similar to the recent analysis in random Mexican sample (3.1% and 13.6% respectively)33. To analyze the lineages autochthonous to the New World, we focused on the classical Native American haplogroups A2, B2, C1, D1 and D4h3, of which the former 4 haplogroups showed star-like patterns. Time estimates were generated according to different methods and rates (Table S2), and the ages of 4 main clusters (A2, B2, C1 and D1) were between the LGM and 13 kya. According to the previous model, these lineages expanded rightly after the LGM via a coastal (Pacific) route from Northern refuge (Beringia) towards the south. The dispersal to the whole America continent was accomplished in a very short time, probably in just several thousand years313234353637.


MtDNA analysis of global populations support that major population expansions began before Neolithic Time.

Zheng HX, Yan S, Qin ZD, Jin L - Sci Rep (2012)

American expansion lineages from median-joining network.Star expansions were selected from median-joining network of 184 Ameican mtDNA coding region sequences corresponding to rCRS positions 577–16023.Blue, CLM; yellow, MXL; Green, PUR. Red squares and numbers indicate clusters with distinct expansions. 1, A2; 2, A2w; 3, B2; 4, B2d; 5, C1; 6, D1. Branch length is proportional to steps of mutations and red arrows indicate the root.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3475341&req=5

f6: American expansion lineages from median-joining network.Star expansions were selected from median-joining network of 184 Ameican mtDNA coding region sequences corresponding to rCRS positions 577–16023.Blue, CLM; yellow, MXL; Green, PUR. Red squares and numbers indicate clusters with distinct expansions. 1, A2; 2, A2w; 3, B2; 4, B2d; 5, C1; 6, D1. Branch length is proportional to steps of mutations and red arrows indicate the root.
Mentions: For Native Americans, we observed six expansions of lineages, of which four (A2, B2, C1 and D1) were shared by different populations. The four lineages were also the main constitutions and founding lineages in American gene pool303132. The remaining 2 lineages, B2d and A2w were CLM-specific (see Figure 6). As expected, we found some African L lineages and European N lineages which might be admixed from recent contacts with immigrants. For example, in MXL, African component (U6) was about 3% and European component (H, V and W) was about 12% (Table S4), similar to the recent analysis in random Mexican sample (3.1% and 13.6% respectively)33. To analyze the lineages autochthonous to the New World, we focused on the classical Native American haplogroups A2, B2, C1, D1 and D4h3, of which the former 4 haplogroups showed star-like patterns. Time estimates were generated according to different methods and rates (Table S2), and the ages of 4 main clusters (A2, B2, C1 and D1) were between the LGM and 13 kya. According to the previous model, these lineages expanded rightly after the LGM via a coastal (Pacific) route from Northern refuge (Beringia) towards the south. The dispersal to the whole America continent was accomplished in a very short time, probably in just several thousand years313234353637.

Bottom Line: With the benefit of 1000 Genome Project, we were able to analyze a total of 910 samples from 11 populations in Africa, Europe and Americas.Furthermore, major population expansions were estimated after Last Glacial Maximum but before Neolithic Time, also corresponding to the result of major lineage expansions.Considering results in current and previous study, global mtDNA evidence showed that rising temperature after Last Glacial Maximum offered amiable environments and might be the most important factor for prehistorical human expansions.

View Article: PubMed Central - PubMed

Affiliation: MOE Key Laboratory of Contemporary Anthropology and Center for Evolutionary Biology, School of Life Sciences and Institutes of Biomedical Sciences, Fudan University, Shanghai, China.

ABSTRACT
Agriculture resulted in extensive population growths and human activities. However, whether major human expansions started after Neolithic Time still remained controversial. With the benefit of 1000 Genome Project, we were able to analyze a total of 910 samples from 11 populations in Africa, Europe and Americas. From these random samples, we identified the expansion lineages and reconstructed the historical demographic variations. In all the three continents, we found that most major lineage expansions (11 out of 15 star lineages in Africa, all autochthonous lineages in Europe and America) coalesced before the first appearance of agriculture. Furthermore, major population expansions were estimated after Last Glacial Maximum but before Neolithic Time, also corresponding to the result of major lineage expansions. Considering results in current and previous study, global mtDNA evidence showed that rising temperature after Last Glacial Maximum offered amiable environments and might be the most important factor for prehistorical human expansions.

Show MeSH
Related in: MedlinePlus