Creationists often portray natural selection —usually citing Herbert Spencer’s expression, “survival of the fittest”— as being a matter of the strong subjugating or eliminating the weak, usually tying it to eugenics, racism and ultimately (of course) to Adolf Hitler.
Here is a fun cartoon by Jay Hosler (author of Drawing Flies) that amusingly illustrates that this is at best an extreme oversimplification of the how natural selection actually works (click on the image for a larger version).
Of course it does sometimes happen in nature that organisms attempt to directly eliminate competition for resources—lions killing hyenas (between species), older larger bird chicks pushing younger siblings out of the nest (within a species)— but it is usually through the more indirect method of simply leaving more offspring and thus eventually dominating the environment. That way the competition fizzles out and goes extinct on its own rather than being directly attacked in any way.
Also such “might makes right” caricatures of natural selection ignore the fact that cooperative behavior within species can also lead to increased “fitness” as is seen in social species like ourselves as well as between different species as is the case with mutualistic relationships; the Yucca plant and some species of Yucca Moths for example.
Then there is the problem that creationists are trying to project the is-ought fallacy onto evolution. The idea being that though the process of natural selection sometimes leads to behavior that we would normally consider cruel or immoral, since it is natural, it is therefore good and we should encourage it.
However the mere fact that we observe something to happen in nature in one context does not mean that it is something upon which we would want to model our own behavior. In fact our success as a species in largely due to the fact that we don’t model our behavior on what we see in nature, or allowing nature to take its course.
Evolution and Philosophy – Does evolution make might right? by John S. Wilkins
[Hat tip to NCSE on Facebook for the cartoon]