Additive genetic variance for lifetime fitness and the capacity for adaptation in an annual plant
Additive genetic variance for lifetime fitness and the capacity for adaptation in an annual plant
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一年生植物终生健康和适应能力的加性遗传方差
DOI：
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
R. Shaw
中科院分区：
文献类型：
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作者：
M. W. Kulbaba;S. Sheth;R. Pain;V. Eckhart;R. Shaw
在当前环境条件下的即时适应能力与适应性的加性遗传方差VA(W)成正比。根据费雪的自然选择基本定理，平均绝对适合度预计会以一定的速率变化。尽管有大量的研究评价了局部适应程度，但对VA(W)和持续适应能力的直接评估却极为罕见。我们在野外对3个纯种的一年生美洲斑叶蝉种群进行了3年的VA(W)估算。与通常的预期相反，我们发现所有种群和年份的VA(W)都显著增加，预测后代的平均适应度增加（每个体0.83至6.12颗种子）。此外，我们发现了两个预测“进化拯救”的案例，其中对站立VA(W)的选择预计将使下降种群（< 1.0）的适应度提高到与种群可持续性和增长相一致的水平。在种群内，适合度基因表达的年际差异是显著的。显著的基因型-年交互作用反映了不同年份育种值之间的适度相关性（均r < 0.490），表明在基因型水平上存在时间变量选择；可能有助于维持VA(W)。通过直接估算VA(W)和总寿命，本研究为野外适应能力的研究提供了一种实验方法。
The immediate capacity for adaptation under current environmental conditions is directly proportional to the additive genetic variance for fitness, VA(W). Mean absolute fitness, , is predicted to change at the rate , according to Fisher’s Fundamental Theorem of Natural Selection. Despite ample research evaluating degree of local adaptation, direct assessment of VA(W) and the capacity for ongoing adaptation is exceedingly rare. We estimated VA(W) and in three pedigreed populations of annual Chamaecrista fasciculata, over three years in the wild. Contrasting with common expectations, we found significant VA(W) in all populations and years, predicting increased mean fitness in subsequent generations (0.83 to 6.12 seeds per individual). Further, we detected two cases predicting “evolutionary rescue”, where selection on standing VA(W) was expected to increase fitness of declining populations ( < 1.0) to levels consistent with population sustainability and growth. Within populations, interannual differences in genetic expression of fitness were striking. Significant genotype-by-year interactions reflected modest correlations between breeding values across years (all r < 0.490), indicating temporally variable selection at the genotypic level; that could contribute to maintaining VA(W). By directly estimating VA(W) and total lifetime , our study presents an experimental approach for studies of adaptive capacity in the wild.
影响因子：
3.3
作者：
D. Houle
通讯作者：
D. Houle