The evolution of marine phytoplankton under extreme polar conditions

海洋浮游植物具有巨大的生物多样性和生物量，然而，尽管它们具有重要的生物学意义，但可悲的是，对这些物种的研究仍然很少。我们是第一个对极地浮游植物物种的基因组进行测序的人，我们的发现震惊了科学界。首先，我们发现该物种的基因组与其他模式物种的基因组有根本的不同。我们发现了积极选择的压倒性特征，并发现它的很大一部分基因是通过自然选择而不是遗传漂移来进化的。这一发现与最基本的进化论--木村(1968)的中立论相悖。因此，基于对经典模式物种(如果蝇)的研究而发展起来的理论可能不足以理解海洋浮游植物的进化。其次，我们发现这种海洋浮游植物物种以一种独特的方式利用它的遗传变异，这提供了显著的进化优势；它可以根据有机体遇到的环境表达不同的等位基因集(Mock等人。2017年。自然541,536-540)。

Marine phytoplankton has a huge biodiversity and biomass, yet despite its biological importance, these species remain woefully understudied. We were the first to sequence the genome of a polar phytoplankton species, and what we discovered shocked the scientific community. Firstly, we found that the genome of this species is fundamentally different from the genomes of other "model" species. We detected an overwhelming signature of positive selection, and discovered that a large proportion of its genes is evolving by natural selection, rather than by genetic drift. This finding flies in the face of the most fundamental theory of evolution, Kimura's (1968) Neutral Theory. It thus appears that the theory developed based on studies of classical model species (e.g. Drosophila) might be inadequate to understand the evolution of marine phytoplankton. Secondly, we discovered that this marine phytoplankton species employs its genetic variation in a unique manner which offers a significant evolutionary advantage; it can express alternative sets of alleles depending on the environment the organism encounters (Mock et al. 2017. Nature 541, 536-540).