個々の全ゲノム配列からヒトの人口史の推論
1The Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK.
Nature
|July 15, 2011
まとめ
人口の歴史は,10万~6万年前に東アジアと欧州の集団に明確なボトルネックがあることを示している. アフリカの集団は,より軽度のボトルネックを経験し,より早く回復し,すべての集団は6万~25万年前に大きくなっていた.
科学分野:
- 集団遺伝学 人口遺伝学
- 人間の進化 人類の進化
- パレオゲノミクスとは
背景:
- 人口規模の歴史を理解することは,人間の進化研究にとって極めて重要です.
- 以前の研究で,東アジアとヨーロッパの集団における,アフリカ外での分散に関連した創設者イベント (ボトルネック) が特定されました.
- 既存の研究は,しばしば簡略化された人口統計モデルに依存し,正確なボトルネックタイミングが欠けている.
研究 の 目的:
- 1万年前から100万年前までの人類の人口規模に関する詳細な歴史を提示する.
- 以前の研究と比較して,人口規模の変化に関する仮定を減らすために.
- 人口のボトルネックのタイミングと重さを推論するために,異なる人間のグループで.
主な方法:
- パアウェイズ・シーケンシャル・マルコヴィアン・コアレスセント (PSMC) モデルの適用.
- 多種多様な個体 (中国人,韓国人,ヨーロッパ人,ヨルバ人) の完全な二倍体ゲノム配列の分析.
- 集団の大きさの変化に関する仮定は少なかった.
主要な成果:
- ヨーロッパ人と中国人の人口は10~20億年前まで,同じ規模の歴史を共有していた.
- ヨーロッパと中国では10~60年前,深刻なボトルネックが発生した.
- アフリカの個体群は,より軽く,早期に回復するボトルネックを経験し,60〜250年前には,おそらくサブストラクチャのせいで,効果的な個体群のサイズが上昇した.
- 人間の遺伝的差異化は100〜120年前に始まり,遺伝的交換は20〜40年前まで続いていた.
結論:
- この研究は,モデル仮定が少ないヒト集団の精巧な人口統計的歴史を提供します.
- 人口の大きさの大きな変動とボトルネックが,異なる人類の祖先で発生した.
- 推論は,ヒトの遺伝的差異化と集団間の遺伝子フローの複雑なタイムラインを示唆しています.
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