研究人员揭示了莫桑比克内战期间（1977年至1992年）象牙偷猎对戈龙戈萨国家公园的非洲草原象（Loxodonta africana）进化的影响。偷猎导致了强烈的选择，在种群迅速减少的情况下有利于无牙象。调查数据显示，象牙遗传模式与X染色体相关的显性、男性致死性状一致。全基因组扫描显示，两个候选基因在哺乳动物牙齿发育中具有已知的作用（AMELX和MEP1a），包括釉质、牙质、牙骨质和牙周的形成。其中一个基因座（AMELX）与人类的X连锁显性男性致死综合征有关，该综合征使上颌侧切牙（与大象牙同源）的生长减弱。这项研究提供了在一个关键物种中快速的、以偷猎为媒介的对一个突出解剖学特征丧失的选择证据。
据介绍，随着采伐的效率越来越高，了解野生动物的进化后果也越来越重要。
附：英文原文
Title: Ivory poaching and the rapid evolution of tusklessness in African elephants
Author: Shane C. Campbell-Staton, Brian J. Arnold, Dominique Gonalves, Petter Granli, Joyce Poole, Ryan A. Long, Robert M. Pringle
Issue&Volume: 2021-10-22
Abstract: Understanding the evolutionary consequences of wildlife exploitation is increasingly important as harvesting becomes more efficient. We examined the impacts of ivory poaching during the Mozambican Civil War (1977 to 1992) on the evolution of African savanna elephants (Loxodonta africana) in Gorongosa National Park. Poaching resulted in strong selection that favored tusklessness amid a rapid population decline. Survey data revealed tusk-inheritance patterns consistent with an X chromosome–linked dominant, male-lethal trait. Whole-genome scans implicated two candidate genes with known roles in mammalian tooth development (AMELX and MEP1a), including the formation of enamel, dentin, cementum, and the periodontium. One of these loci (AMELX) is associated with an X-linked dominant, male-lethal syndrome in humans that diminishes the growth of maxillary lateral incisors (homologous to elephant tusks). This study provides evidence for rapid, poaching-mediated selection for the loss of a prominent anatomical trait in a keystone species.
DOI: abe7389
Source: https://www.science.org/doi/10.1126/science.abe7389