an adaptation (= a slight change to a living thing that happens over time so it can continue to exist in a particular environment) as a reaction to an adaptation by another living thing in the same environment

Behavioural change may reflect a counter-adaptation by the host in response to a parasite. 行为变化可能反映了宿主对寄生虫的反适应。

the process in which a living thing adapts (= changes slightly over time to be able to continue to exist in a particular environment) as a reaction to another living thing in the same environment adapting

As time goes on, some of the invading species' population may be eliminated by counter-adaptation. 随着时间的推移，一些入侵物种的种群可能会因为反适应而被消灭。