日本人群的源流一直是東亞地區(qū)人類學(xué)、考古學(xué)和遺傳學(xué)研究的熱點之一,。1991年，埴原和郎（Hanihara Kazuro）提出了著名的“二重構(gòu)造理論”（dual structure model）來解釋日本人群的歷史。該模型認為,，來自東南亞地區(qū)舊石器時代晚期人群首先移居到日本列島，創(chuàng)造了日本新石器文化——繩文文化（Jomon Culture）,，生產(chǎn)方式以狩獵采集為主,；隨著源自東北亞地區(qū)的第二批移民的到來，日本進入到以彌生文化（Yayoi Culture）為代表的銅石并用時代，生產(chǎn)方式轉(zhuǎn)為農(nóng)業(yè)栽培,；這兩批移民的經(jīng)過相互混合,，逐漸形成了今天的日本人群。然而,，關(guān)于繩文文化是如何向彌生文化轉(zhuǎn)變的問題卻依舊備受爭議,。
在中國科學(xué)院昆明動物研究所張亞平院士的指導(dǎo)下，博士研究生彭旻晟嘗試著從人類遺傳學(xué)的角度來探討這個問題,。通過對已發(fā)表的952條日本人群的線粒體DNA（mtDNA）基因組進行分析,，研究人員重建了日本人群的群體動態(tài)歷史。結(jié)果顯示,，源自距今約5千年前的群體快速增長事件對現(xiàn)今日本人群的母系遺傳庫的形成起到了重要的作用,。該時期大約對應(yīng)于日本繩文時代中期，考古學(xué)證據(jù)表明當(dāng)時的生產(chǎn)技術(shù)有了一定的進步,，先民甚至開始馴化一些植物（例如稗子和葫蘆）,，因此人口經(jīng)歷也了顯著的增長。
有意思的是,，這次群體快速增長一直持續(xù)至今,，表明繩文文化向彌生文化的轉(zhuǎn)變是一個“平順”的過程，即不同時代的人口增長的態(tài)勢是相互銜接的,。這提示出,，由于具備了相關(guān)的一些農(nóng)業(yè)生產(chǎn)經(jīng)驗，繩文先民能夠很快掌握隨后由彌生時代移民傳入的,、更為先進的農(nóng)業(yè)生產(chǎn)方式（例如水稻的水田栽培）,，繼而在隨后的彌生時代依舊保持人口的快速增長。
該研究發(fā)表在國際開源刊物《公共科學(xué)圖書館—綜合》（PLoS ONE）上,。（生物谷Bioon.com）
生物谷推薦原文出處：
PLoS ONE doi:10.1371/journal.pone.0021509
Inferring the Population Expansions in Peopling of Japan
Min-Sheng Peng, Ya-Ping Zhang
Background
Extensive studies in different fields have been performed to reconstruct the prehistory of populations in the Japanese archipelago. Estimates the ancestral population dynamics based on Japanese molecular sequences can extend our understanding about the colonization of Japan and the ethnogenesis of modern Japanese.
Methodology/Principal Findings
We applied Bayesian skyline plot (BSP) with a dataset based on 952 Japanese mitochondrial DNA (mtDNA) genomes to depict the female effective population size (Nef) through time for the total Japanese and each of the major mtDNA haplogroups in Japanese. Our results revealed a rapid Nef growth since ~5 thousand years ago had left ~72% Japanese mtDNA lineages with a salient signature. The BSP for the major mtDNA haplogroups indicated some different demographic history.
Conclusions/Significance
The results suggested that the rapid population expansion acted as a major force in shaping current maternal pool of Japanese. It supported a model for population dynamics in Japan in which the prehistoric population growth initiated in the Middle Jomon Period experienced a smooth and swift transition from Jomon to Yayoi, and then continued through the Yayoi Period. The confounding demographic backgrounds of different mtDNA haplogroups could also have some implications for some related studies in future.
