美国国家海洋和大气管理局、加州大学和墨西哥国家自然保护区委员会等团队合作的研究证明，极度濒危的小头鼠海豚并不会因为近交衰退而灭绝。这一研究成果于2022年5月6日发表在国际学术期刊《科学》上。

研究人员分析了20只小头鼠海豚的全基因组序列，并将基因组和数量统计信息整合到基于个体的随机模拟中，以量化该物种的恢复潜力。研究分析表明，小头鼠海豚的历史稀有性导致分离有害变异的负担较低，从而降低了近交衰退的风险。同样，基于基因组的模拟表明，如果立即停止捕捞，小头鼠海豚可以恢复。该研究为小头鼠海豚和其他自然稀有濒危物种的恢复提供了希望，并强调了基因组学在预测灭绝风险方面的效用。

据悉，在野生动物数量严重下降的情况下，物种恢复工作的一个关键问题是其是否会受到遗传因素的阻碍，例如近交衰退。几十年来，刺网捕捞造成的超额死亡率使墨西哥的小头鼠海豚仅剩约10只。

附：英文原文

Title: The critically endangered vaquita is not doomed to extinction by inbreeding depression

Author: Jacqueline A. Robinson, Christopher C. Kyriazis, Sergio F. Nigenda-Morales, Annabel C. Beichman, Lorenzo Rojas-Bracho, Kelly M. Robertson, Michael C. Fontaine, Robert K. Wayne, Kirk E. Lohmueller, Barbara L. Taylor, Phillip A. Morin

Issue&Volume: 2022-05-06

Abstract: In cases of severe wildlife population decline, a key question is whether recovery efforts will be impeded by genetic factors, such as inbreeding depression. Decades of excess mortality from gillnet fishing have driven Mexico’s vaquita porpoise (Phocoena sinus) to ~10 remaining individuals. We analyzed whole-genome sequences from 20 vaquitas and integrated genomic and demographic information into stochastic, individual-based simulations to quantify the species’ recovery potential. Our analysis suggests that the vaquita’s historical rarity has resulted in a low burden of segregating deleterious variation, reducing the risk of inbreeding depression. Similarly, genome-informed simulations suggest that the vaquita can recover if bycatch mortality is immediately halted. This study provides hope for vaquitas and other naturally rare endangered species and highlights the utility of genomics in predicting extinction risk.

DOI: abm1742

Source: https://www.science.org/doi/10.1126/science.abm1742