What are r-selected species?
r selected species are those that emphasise high growth rates, typically exploit less crowded ecological niches, and produce many offsprings.
r selected species live in populations that are highly variable. The fittest individual in these environments have many offsprings and reproduce early. However these offsprings have a relatively low probability of surviving to adulthood.
In unstable or unpredictable environments r selection predominates due to the ability to reproduce quickly. There is little advantage in adaptations that permit successful competition with other organisms, as the environment is likely to change again.
Organisms that exhibit r selection range from bacteria and diatoms, to insects and grasses, various semelparous cephalopods, small mammals, particularly rodents.