As a general rule, / when the individuals of a population encounter a new environmental stress, / some individuals in the population will die prematurely / and some individuals will survive.

If the reason for their survival / (such as a slightly enhanced ability or trait) / can be passed on to their offspring / (that is, it's genetically encoded), / then the next generation should be better able / to withstand the newly encountered environmental stress, / and the population overall will be less susceptible to it.

Therefore, / the key to the ability of a population to survive by adaptation / lies in the rapidity / with which the next generation, the more resistant generation, is produced / by the survivors of this generation.

It follows that / those species capable of producing a new generation very quickly / should be better able / to respond to a stress very quickly.

Those species that require more time for reproduction / will be slower to adapt to the stress / because of the additional time needed / for them to produce stress-tolerant offspring.