DOI: 10.5683/sp3/8q7pfs
title: Data for: Multi-generational fitness effects of natural immigration indicate strong heterosis and epistatic breakdown in a wild bird population

description: &lt;b&gt;Abstract&lt;/b&gt;&lt;br/&gt;&lt;p&gt;&lt;span lang="en-US"&gt;The fitness of immigrants and their descendants produced within recipient populations fundamentally underpins the genetic &lt;/span&gt;&lt;span lang="en-US"&gt;and population dynamic&lt;/span&gt;&lt;span lang="en-US"&gt; consequences of immigration. &lt;/span&gt;&lt;span lang="en-US"&gt;I&lt;/span&gt;&lt;span lang="en-US"&gt;mmigrants can &lt;/span&gt;&lt;span lang="en-US"&gt;in principle &lt;/span&gt;&lt;span lang="en-US"&gt;induce contrasting genetic effects on fitness across generations, reflecting multi-faceted additive, dominance, and epistatic effects. Y&lt;/span&gt;&lt;span lang="en-US"&gt;et, full multi-generational and sex-specific fitness effects of regular immigration have not been quantified within naturally structured systems, precluding inference on underlying genetic architectures &lt;/span&gt;&lt;span lang="en-US"&gt;and population outcomes&lt;/span&gt;&lt;span lang="en-US"&gt;. We used four decades of song sparrow &lt;/span&gt;&lt;span lang="en-US"&gt;(&lt;em&gt;Melospiza melodia&lt;/em&gt;)&lt;/span&gt; &lt;span lang="en-US"&gt;life-history and pedigree data to quantify fitness of natural immigrants, natives, and their F1, F2, and backcross descendants, and test for evidence of non-additive genetic effects. Values of key fitness components (including adult lifetime reproductive success and zygote survival) of F1 offspring of immigrant-native matings substantially exceeded their parent mean, indicating strong heterosis. Meanwhile, F2 offspring of F1-F1 matings had notably low values, indicating surprisingly strong epistatic breakdown. Further, magnitudes of effects varied among fitness components, and&lt;/span&gt; &lt;span lang="en-US"&gt;differed between female&lt;/span&gt;&lt;span lang="en-US"&gt;s&lt;/span&gt;&lt;span lang="en-US"&gt; and male&lt;/span&gt;&lt;span lang="en-US"&gt;s&lt;/span&gt;&lt;span lang="en-US"&gt; descendants. These results demonstrate that strong non-additive genetic effects on fitness can arise within &lt;/span&gt;&lt;span lang="en-US"&gt;weakly &lt;/span&gt;&lt;span lang="en-US"&gt;structured &lt;/span&gt;&lt;span lang="en-US"&gt;and fragmented &lt;/span&gt;&lt;span lang="en-US"&gt;populations &lt;/span&gt;&lt;span lang="en-US"&gt;experiencing &lt;/span&gt;&lt;span lang="en-US"&gt;frequent &lt;/span&gt;&lt;span lang="en-US"&gt;natural &lt;/span&gt;&lt;span lang="en-US"&gt;immigration. &lt;/span&gt;&lt;span lang="en-US"&gt;Such effects will substantially affect the net &lt;/span&gt;&lt;span lang="en-US"&gt;degree of effective gene flow and resulting local genetic introgression and adaptation.&lt;/span&gt;&lt;/p&gt;
description: &lt;b&gt;Methods&lt;/b&gt;&lt;br /&gt;&lt;p&gt;These data come from the long-term song sparrow field study on Mandarte Island, BC, Canada (latitude 48.6329°, longitude -123.2859°). The data provided here are sufficient to replicate the analyses presented in the above paper, and are therefore a restricted subset of the full Mandarte dataset.&lt;/p&gt;
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