What does a deleterious mutation do to an organism?

A deleterious mutation refers to a genetic change that lowers the fitness of an organism, negatively impacting its ability to survive and reproduce. This definition is rooted in the concept of evolutionary fitness, which encompasses an organism's overall ability to pass on its genes to the next generation. When a mutation is classified as deleterious, it frequently leads to harmful effects, such as disruption of essential biological functions, increased susceptibility to diseases, or reduced reproductive success.

In contrast, other types of mutations can either have no effect on fitness or enhance it by providing beneficial traits that improve an organism's chances of survival in a given environment. Thus, understanding the role of deleterious mutations is crucial in the study of evolution, as they can drive natural selection by reducing the frequency of unfavorable traits within a population over time.