据介绍，直接观察是人们理解适应的核心，但在大型多细胞生物中，很少有超过几代的演化记录。
研究人员观察了一个世纪尺度的竞争实验，大麦复合杂交II（CCII）的演化。CCII于1929年在加利福尼亚州戴维斯成立，拥有数千种基因型，但研究人员发现自然选择大大降低了遗传多样性，导致到50代时，一个单一的谱系构成了大部分类群。选择有利于源自与戴维斯气候相似的等位基因和有助于生殖发育的靶位点，包括大麦多样化位点Vrs1、HvCEN、Ppd-H1和Vrn-H2。
总之，这一研究结果表明，在世界上最古老的生物实验之一中，选择是塑造基因组变异的主要力量。
附：英文原文
Title: Natural selection drives emergent genetic homogeneity in a century-scale experiment with barley
Author: Jacob B. Landis, Angelica M. Guercio, Keely E. Brown, Christopher J. Fiscus, Peter L. Morrell, Daniel Koenig
Issue&Volume: 2024-07-12
Abstract: Direct observation is central to our understanding of adaptation, but evolution is rarely documented in a large, multicellular organism for more than a few generations. In this study, we observed evolution across a century-scale competition experiment, barley composite cross II (CCII). CCII was founded in 1929 in Davis, California, with thousands of genotypes, but we found that natural selection has massively reduced genetic diversity, leading to a single lineage constituting most of the population by generation 50. Selection favored alleles originating from climates similar to that of Davis and targeted loci contributing to reproductive development, including the barley diversification loci Vrs1, HvCEN, Ppd-H1, and Vrn-H2. Our findings point to selection as the predominant force shaping genomic variation in one of the world’s oldest biological experiments.
DOI: adl0038
Source: https://www.science.org/doi/10.1126/science.adl0038