Seasonal time constraints reduce genetic variation in life-history traits along a latitudinal gradient.
Seasonal time constraints reduce genetic variation in life-history traits along a latitudinal gradient.
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季节性时间限制减少了生活史特征沿纬度梯度的遗传变异。
DOI：
10.1111/1365-2656.12442
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
F. Johansson
中科院分区：
文献类型：
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作者：
S. Sniegula;M. Golab;S. Drobniak;F. Johansson
时间限制导致了对生活史特征的强烈选择，因为种群需要在更短的时间内完成它们的生命周期。因此，我们预计这些性状在高纬度人群中的遗传变异低于低纬度人群，因为前者更受时间限制。目的是估计生活史特征和它们的遗传变异在一个专性一化性豆娘沿着纬度梯度2730公里。种群在实验室中在模拟其原产地的温度和光周期下生长。在一个补充实验中，来自相同家庭的个体在恒定的温度和光照周期下生长，模拟整个纬度的平均条件。在北方纬度，发育时间和大小分别更快和更小，生长速度更高。生活史性状的加性遗传方差非常低，卵发育时间和幼虫生长速率的估计值显示出向北方纬度显着下降。当个体生长在恒定的而不是模拟的和自然变化的条件下时，生活史性状的遗传效应的表达有很大不同。我们的研究结果支持强选择的时间限制。他们还强调了在原生环境中生长生物体对于正确估计其原产地遗传变异的重要性。我们的研究结果还表明，生活史特征的进化潜力在北方与南方纬度相比非常低，但气候的变化可能会改变这种模式。
Time constraints cause strong selection on life-history traits, because populations need to complete their life cycles within a shorter time. We therefore expect lower genetic variation in these traits in high- than in low-latitude populations, since the former are more time-constrained. The aim was to estimate life-history traits and their genetic variation in an obligately univoltine damselfly along a latitudinal gradient of 2730 km. Populations were grown in the laboratory at temperatures and photoperiods simulating those at their place of origin. In a complementary experiment, individuals from the same families were grown in constant temperature and photoperiod that mimicked average conditions across the latitude. Development time and size was faster and smaller, respectively, and growth rate was higher at northern latitudes. Additive genetic variance was very low for life-history traits, and estimates for egg development time and larval growth rate showed significant decreases towards northern latitudes. The expression of genetic effects in life-history traits differed considerably when individuals were grown in constant rather than simulated and naturally variable conditions. Our results support strong selection by time constraints. They also highlight the importance of growing organisms in their native environment for correct estimates of genetic variance at their place of origin. Our results also suggest that the evolutionary potential of life-history traits is very low at northern compared to southern latitudes, but that changes in climate could alter this pattern.