Science 5

Organisms often compete for limited resources such as food and habitat. Organisms competing with others of the same species are said to be competing intraspecifically. Organisms competing with members of a different species are said to be competing interspecifically. Two scientists discuss the effects of each.

Scientist 1

Interspecific competition is one of the chief reasons that organisms evolve into specially adapted “harvesters.” If two species of organisms are competing for a single resource, one species is bound to be the better competitor, and will drive the other species to extinction. Because certain groups are excluded from certain resources, species will diverge and develop specialized traits unique to their feeding environment. Should another species try to invade this feeding environment, the already adapted indigenous species will outcompete and exclude this invasive species.

Scientist 2

Several species may inhabit the same feeding environment. Depending on the population of each of these species, one may observe various intensities of both interspecific and intraspecific competition. If more than one species is abundant in a single feeding environment, interspecific competition drives the population dynamics until one species outcompetes the others. At this point, intraspecific competition becomes a dominant force, as members of the single abundant species must outcompete each other for food resources. After some time, this heightened intraspecific competition may allow another species to invade the feeding environment and reproduce. This then leads again to interspecific competition. This intra-interspecific competition cycle will then continue.