Data and Code for: Reproductive strategies and their consequences for divergence, gene flow, and genetic diversity in three taxa of Clarkia

Differences in reproductive strategies can have important implications for
macro- and micro-evolutionary processes. We used a comparative approach
through a population genetics lens to evaluate how three distinct
reproductive strategies shape patterns of divergence among as well as gene
flow and genetic diversity within three closely related taxa in the genus
Clarkia. One taxon is a predominantly autonomous self-fertilizer and the
other two taxa are predominantly outcrossing but vary in the primary
pollinator they attract. In genotyping populations using
genotyping-by-sequencing and comparing loci shared across taxa, our
results suggest that differences in reproductive strategies in part
promote evolutionary divergence among these closely related taxa. Contrary
to expectations, we found that the selfing taxon had the highest levels of
heterozygosity but a low rate of polymorphism. The high levels of fixed
heterozygosity for a subset of loci suggests this pattern is driven by the
presence of structural rearrangements in chromosomes common in other
Clarkia taxa. In evaluating patterns within taxa, we found a complex
interplay between reproductive strategy and geographic distribution.
Differences in the mobility of primary pollinators did not translate to a
difference in rates of genetic diversity and gene flow within taxa – a
pattern likely due to one taxon having a patchier distribution and a less
temporally and spatially reliable pollinator. Taken together, this work
advances our understanding of the factors that shape gene flow and the
distribution of genetic diversity within and among closely related taxa.

生殖策略差异对宏观与微观进化过程均具有重要意义。本研究采用种群遗传学视角下的比较研究方法，旨在探究三种不同生殖策略如何塑造克拉克花属（Clarkia）三个近缘类群间的分化模式，以及类群内的基因流与遗传多样性分布格局。其中一个类群以自主自交为主，另外两个类群以异交为主，但二者所吸引的主要传粉者存在差异。本研究通过测序分型法（genotyping-by-sequencing）对种群进行基因型分型，并比对各共享基因座，结果显示生殖策略差异在一定程度上推动了这些近缘类群间的进化分化。与预期相悖的是，自交类群的杂合度水平最高，但多态性速率较低。部分基因座呈现高固定杂合性，这一现象表明该模式由其他克拉克花属类群中常见的染色体结构重排所驱动。在分析类群内的格局时，我们发现生殖策略与地理分布之间存在复杂的相互作用。主要传粉者的移动性差异并未导致类群内遗传多样性与基因流速率出现差异——这一模式可能源于其中一个类群的分布呈斑块状，且其传粉者的时空可靠性较低。综上，本研究加深了我们对塑造近缘类群内外基因流与遗传多样性分布格局的影响因素的认知。