self-copulation

例句：

1. 1.In the study of genetics, self-copulation is a crucial concept to understand how genes are passed on from one generation to the next.
   在遗传学研究中，自交是一个关键的概念，它帮助我们理解基因是如何从一代传到下一代的。
2. 2. The process of self-copulation can be observed in many species, including humans, where malesmate with females of their own species.
   自交的过程可以在许多物种中观察到，包括人类，其中雄性与自己的雌性物种进行交配。
3. 3. Self-copulation has been shown to have evolutionary benefits, such as reducing genetic diversity and increasing fitness.
   研究表明，自交具有进化优势，如减少遗传多样性和提高适应性。