Why does nature tolerate males? They produce no offspring of their own, one consequence of which is that populations of plants and animals capable of self-fertilisation, or “selfing”, grow at twice the rate of populations that depend on sexual reproduction.
自然界为何会容许雄性的存在？他们不会繁衍自己的后代，一个后果就是，能够自体受精的动植物数量的增长率，是依赖有性生殖的两倍。

　　Yet, there must be evolutionary advantage in sex with a partner. Scientists at Oregon university argue in Nature magazine that their research with roundworms – which can self-fertilise or reproduce sexually – shows selfing populations are more susceptible to harmful genetic mutations and slow to adapt to swiftly changing environmental conditions. “Selfing populations are more likely to become extinct,” said Levi Morran, lead author.
不过，与性伙伴发生性行为必然有其进化上的优势。俄勒冈大学(Oregon university)的科学家在《自然》杂志(Nature)上撰文称，在对既可以自体受精、也能够有性繁殖的蛔虫进行研究后发现，自体受精的后代更容 易受到有害基因突变的影响，对迅速变化的环境条件的适应速度也比较慢。该论文第一作者里维•莫伦(Levi Morran)表示：“自体受精的生物更容易灭绝。”

　　Yet, selfing populations thrive and survive. One explanation, based on a discovery in rice plants which Susan Wessler of the University of Georgia described as “brand new and really stunning”, is that movable genetic material called transposable elements insert themselves at various points in the chromosomes, providing a source of genetic variation in response to changing conditions.

　　然而，自体受精的生物兴旺繁 殖并生存了下来。佐治亚大学(University of Georgia)教授苏珊•韦斯勒(Susan Wessler)对水稻的研究发现可以对此做出解释——苏珊形容自己的研究发现“是全新的，的确令人惊奇”。她发现，被称为转座因子的可移动遗传物质将自 己嵌入染色体中不同位置，造成基因变异，以应对不断变化的环境。