Correct Response: D. Existing species can sometimes alter environmental conditions, such as by changing the mineral composition of the soil. When these changes inhibit the species' ability to reproduce relative to other species, this opens the door for other species that are better suited to the new environment to grow and thrive. These new, better suited species begin to dominate the environment in a process called secondary succession. Density-independent selection (A) refers to factors such as natural disasters that affect a species regardless of the species' population size. Habitat fragmentation (B) affects a species by splitting its habitat into varying sizes, which might cause a change in the number of the species but it is not caused by the self-inhibition of reproduction. Boom and bust population cycles (C) occur as a result of the abiotic factors of space, nutrients, and water in an environment. When these factors are readily available, the population increases, but when they are depleted, the population decreases. This is not caused by a species inhibiting its own reproduction.
