在大型酵母种群中,平分体的进化优势是酵母种群的进化优势
Clifford Zeyl1, Thomas Vanderford, Michele Carter
1Department of Biology, Wake Forest University, Winston-Salem, NC 27109, USA. zeylcw@wfu.edu
概括
二倍体,有两组基因,并不总是加速适应. 在酵母种群中,二倍体减缓了大群体的适应,但对小群体没有影响,特别是当有益的突变是部分衰退时.
科学领域:
- 进化生物学是进化的生物学.
- 遗传学 是一个遗传学.
背景情况:
- 双体性 (两个基因副本) 在植物和动物中很常见,但它的进化优势尚不清楚.
- 虽然双倍体性可能会增加有益突变率,但模型表明它可能并不总是加速适应.
研究的目的:
- 为了测试模型对二倍体和二倍体种群适应率的预测.
- 通过实验进化来研究 ploidy 对进化适应的影响.
主要方法:
- 使用无性酵母种群来实验性地比较适应率.
- 操纵了人口规模,并评估了 ploidy 的影响 (diploidy 和 haploidy).
- 具有有益突变的主导特征.
主要成果:
- 适应性突变被发现是,平均而言,部分衰退.
- 二倍体性显著减缓了大种群的适应.
- 双胞胎性并没有显著影响小种群的适应率.
结论:
- 实验结果与理论模型一致,这些理论模型预测双倍体质会阻碍适应.
- 二倍体性对适应的影响取决于种群大小.
- 突变主导性影响了 ploidy 对进化轨迹的影响.
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