The loss of biodiversity in Madagascar is contemporaneous with major demographic events 作者：Omar Alva, Anaïs Leroy, Margit Heiske, Veronica Pereda-Loth, Lenka Tisseyre, Anne Boland, Jean-François Deleuze, Jorge Rocha, Carina Schlebusch, Cesar Fortes-Lima, Mark Stoneking, Chantal Radimilahy, Jean-Aimé Rakotoarisoa, Thierry Letellier, Denis Pierron Person Envelope Current Biology：2022/11/04
Only 400 km off the coast of East Africa, the island of Madagascar is one of the last large land masses to have been colonized by humans. While many questions surround the human occupation of Madagascar, recent studies raise the question of human impact on endemic biodiversity and landscape transformation. Previous genetic and linguistic analyses have shown that the Malagasy population has emerged from an admixture that happened during the last millennium, between Bantu-speaking African populations and Austronesian-speaking Asian populations. By studying the sharing of chromosome segments between individuals (IBD determination), local ancestry information, and simulated genetic data, we inferred that the Malagasy ancestral Asian population was isolated for more than 1,000 years with an effective size of just a few hundred individuals. This isolation ended around 1,000 years before present (BP) by admixture with a small African population. Around the admixture time, there was a rapid demographic expansion due to intrinsic population growth of the newly admixed population, which coincides with extensive changes in Madagascar’s landscape and the extinction of all endemic large-bodied vertebrates. Therefore, our approach can provide new insights into past human demography and associated impacts on ecosystems. 马达加斯加岛位于东非海岸250英里（400多公里）外，是最后一批被人类殖民的大片陆地之一。虽然，目前马达加斯加岛的生物多样性也非常独特，但很久以前，这里就失去了所有的大型脊椎动物，包括巨型狐猴、象鸟、巨龟和河马。11月4日，一项发表于《当代生物学》（Current Biology）人类基因研究报告称，这些大型脊椎动物的消失与大约1000年前马达加斯加岛首次大规模的人类扩张有关。 为了了解更多马达加斯加人的起源，一个多学科联盟在2007年启动了一个名为“马达加斯加遗传和民族语言”（MAGE）的项目。在10年里，马达加斯加本地和国际研究人员走访了该岛250多个村庄，对人类文化和基因多样性进行取样。在新研究中，研究人员仔细研究了人类染色体的不同片段是如何与当地祖先信息以及计算机模拟的遗传数据共享的。综上所述，他们推断出马达加斯加人的亚洲祖先在岛上隔绝了1000多年，并且有效的人口规模只有几百人。大约1000年前，一小群说班图语的非洲人来到马达加斯加岛，结束了亚洲祖先的与世隔绝。此后，人口持续快速增长。他们认为，不断增长的人口导致马达加斯加地貌发生了广泛的变化，所有曾经生活在那里的大型脊椎动物都消失了。这些发现也能为过去人口变化如何导致整个生态系统的变化提供了新见解。
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