Passage Summary: If a trait is really bad for survival, it'll disappear because the animals without it will eat better and have more babies than the ones with it.

Conclusion: It is unlikely that a significantly harmful trait will last for a long time within an animal population.

Reasoning: Because of genetic diversity, some animals will lack the harmful trait; these individuals will be better at getting resources, allowing them to survive and reproduce more than those with the trait.

Analysis: The statement about competing more successfully functions as a premise that supports an intermediate conclusion. It explains the mechanism by which those without the trait gain a survival advantage. This advantage, in turn, leads to the final conclusion that the maladaptive trait will eventually be crowded out. It is a vital link in the causal chain explaining the process of natural selection described in the stimulus.