Anthropogenic hybridization is one of the greatest threats to global biodiversity. It incites human-mediated gene flow between non-native/exotic and native taxa, which can have irreversible effects on native species or locally adapted populations, eventually leading to extinction. The red deer, Cervus elaphus, is a game species that, due to its extraordinary economic value, has been introduced in several regions throughout Europe. However, the consequences of those introductions on native populations, namely on their genetic background, have been poorly addressed. This study is focused on the Iberian Peninsula and aims to: (i) assess the extent of anthropogenic hybridization/introgression of introduced red deer into the native Iberian populations; (ii) evaluate the impact of red deer management regimes on the observed hybridization/introgression patterns; and (iii) assess how hybridization/introgression influence the current genetic diversity of native Iberian populations. A set of 11 microsatellites and a 329 bases pair fragment of the mitochondrial D-loop gene were used to estimate nuclear admixture and mitochondrial introgression in 1,132 individuals sampled across 46 red deer populations throughout Iberia. A Bayesian approach implemented in the STRUCTURE program was employed to investigate the proportion of admixture between native populations and non-native red deer. Results showed that 17% of individuals presented signs of non-native recent ancestors and 10.1% had non-native mitochondrial haplotypes, reaching an overall hybridization/introgression rate of 23%. Non-native or hybrid individuals were found throughout 40 Iberian red deer populations, and the percentages per population varied between 3.3 and 75.0%, independently of the management regime. Mitochondrial introgression was observed across 15 Iberian red deer populations, being more frequent in free-ranging individuals (16.2%) than in fenced populations (9.2%) but was completely absent from public-owned populations. Nuclear genetic diversity correlated positively with the proportion of hybrid individuals in public-owned populations. The genetic footprint of historical and current human-mediated translocations of non-native red deer into the Iberian Peninsula is evidenced in this study, highlighting the need to implement effective measures to avoid such practices both in Portugal and Spain, in order to preserve the endogenous genetic patrimony of the Iberian red deer populations.

中文翻译：

---

解读人为对伊比利亚半岛马鹿遗传背景的影响

人为杂交是对全球生物多样性的最大威胁之一。它煽动人类介导的非本地/外来和本地分类群之间的基因流动，这可能对本地物种或适应当地的种群产生不可逆转的影响，最终导致灭绝。马鹿，Cervus elaphus，是一种猎物物种，由于其非凡的经济价值，已被引入欧洲多个地区。然而，这些引入对本地人口的影响，即对他们的遗传背景，没有得到很好的解决。这项研究的重点是伊比利亚半岛，旨在：(i) 评估引入的马鹿与伊比利亚本土种群的人为杂交/基因渗入的程度；(ii) 评估马鹿管理制度对观察到的杂交/基因渗入模式的影响；(iii) 评估杂交/基因渗入如何影响当地伊比利亚种群的当前遗传多样性。一组 11 个微卫星和一个 329 碱基对的线粒体 D-loop 基因片段被用于估计在整个伊比利亚的 46 个马鹿种群中采样的 1,132 个人的核混合物和线粒体基因渗入。在 STRUCTURE 程序中实施的贝叶斯方法被用来调查本地种群和非本地马鹿之间的混合比例。结果表明，17% 的个体表现出非本地近代祖先的迹象，10.1% 具有非本地线粒体单倍型，总体杂交/基因渗入率为 23%。在 40 个伊比利亚马鹿种群中发现了非本地或杂交个体，每个种群的百分比在 3.3% 到 75.0% 之间变化，与管理制度无关。在 15 个伊比利亚马鹿种群中观察到线粒体基因渗入，在自由放养的个体 (16.2%) 中比在围栏种群 (9.2%) 中更频繁，但在公有种群中完全没有。核遗传多样性与公有种群中杂种个体的比例呈正相关。本研究证明了历史和当前人类介导的非本地马鹿易位到伊比利亚半岛的遗传足迹，强调需要采取有效措施避免葡萄牙和西班牙的这种做法，