Data from: Admixture of hybrid swarms of native and introduced lizards in cities is determined by the cityscape structure and invasion history

Introductions of non-native lineages increase opportunities for
hybridization. Non-native lineages of the common wall lizard, Podarcis
muralis, are frequently introduced in cities where they hybridize with
native populations. We aimed at unravelling the invasion history and
admixture of native and non-native wall lizards in four German cities
using citywide, comprehensive sampling. We barcoded and genotyped 826
lizards and tested if gene flow in populations composed of admixed native
and introduced lineages is facilitated by similar environmental factors as
in native populations by comparing fine-scale landscape genetic patterns.
In cities with non-native lineages, lizards commonly occurred in numerous
clusters of hybrid swarms, which showed variable lineage composition,
consisting of up to four distinct evolutionary lineages. Hybrid swarms
held vast genetic diversity and showed recent admixture with other hybrid
swarms. Landscape genetic analyses showed differential effects of
cityscape structures across cities, but identified water bodies as strong
barriers to gene flow in both native and admixed populations. In contrast,
railway tracks facilitated gene flow of admixed populations only. Our
study shows that cities represent unique settings for hybridization,
caused by multiple introductions of non-native taxa. Cityscape structure
and invasion histories of cities will determine future evolutionary
pathways at these novel hybrid zones.

非本土谱系的引入会提升杂交事件的发生几率。普通壁蜥（Podarcis muralis）的非本土谱系常被引入城市，并与当地原生种群发生杂交。本研究采用全市范围的全面采样策略，旨在解析德国四座城市中原生与非本土壁蜥的入侵历史及其遗传混合（admixture）情况。我们对826只壁蜥开展了DNA条形码分型（DNA barcoding）与基因分型，并通过比较精细尺度的景观遗传格局，检验了由原生与引入谱系混合形成的种群的基因流，是否受到与原生种群相同的环境因子的促进作用。在存在非本土谱系的城市中，壁蜥常形成大量杂交集群（hybrid swarm），此类集群的谱系组成存在显著差异，最多可包含四种不同的进化谱系。这些杂交集群拥有极高的遗传多样性，且近期与其他杂交集群发生了遗传混合。景观遗传分析（landscape genetic analysis）显示，城市景观结构对不同城市的影响存在异质性，但均证实水体对原生种群与混合种群的基因流均构成强烈阻隔。与之相反，铁路轨道仅能促进混合种群的基因流。本研究表明，城市因多批次引入非本土类群，成为独特的杂交发生环境；城市景观结构与城市入侵历史，将决定这些新型杂交区未来的演化路径。