没有测量的先前生存选择解决了野生大豆羊体型停滞的悖论
Elizabeth A Mittell1,2, Josephine M Pemberton1, Loeske E B Kruuk1
1Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom.
概括
野生种群的自然选择估计可能会受到先前的生存能力选择的偏见. 这项关于大黄羊的研究揭示了对大成人大小的隐藏遗传选择,解决了静止的悖论.
科学领域:
- 进化生物学是进化的生物学.
- 定量遗传学 是一种定量遗传学.
- 生态生态学 生态生态学
背景情况:
- 估计自然选择对于理解野生种群的进化过程至关重要.
- 定量遗传方法往往无法准确预测野生动物的进化变化,这种现象被称为静止悖论.
- 这种错误预测可能源于由于非随机缺失的表型数据而产生偏差的选择估计,特别是在对相关性特征进行可行性选择后.
研究的目的:
- 调查野生大豆羊群自然选择估计中的偏差.
- 确定先前的生存能力选择是否会影响成年人尺寸特征的选择估计.
- 为了解决在大黄羊中观察到的静止悖论,大黄羊的成年人体大小演变.
主要方法:
- 利用定量遗传方法来估计大豆羊的成年体型的终身选择.
- 分析了表型和遗传数据,以评估不同生命阶段的选择压力.
- 在选择估计中调查了潜在的偏差,这些偏差来自于对相关特征的生存能力选择.
主要成果:
- 估计寿命选择的标准方法被发现因先前的生存能力选择而有偏见.
- 现象大小的羊羔在第一年生存率很高,但具有遗传倾向的大型成年羊羔的青少年死亡率较高.
- 基因分析揭示了对较大的成年人体型的对抗性选择,解决了这个人群中成年人体型停滞的悖论.
结论:
- 之前的生存能力选择可以显著偏差野生种群中自然选择的估计.
- 跨越不同生命阶段的敌对选择可以解释尽管明显的方向选择,但没有观察到的进化变化.
- 偏差选择估计的已识别的模式可能在自然种群中广泛存在,这可能解释了先前对大体型的主导积极选择的观察.
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