Invasive Species. Good Or Bad?
There is quite a bit of controversy regarding both the exact meaning of the term “invasive species" as well as what should be done about the issue. Many scientists consider “invasive species", “exotic species", “non-native species" and “introduced species" as meaning virtually the same thing, while others believe that a species should be considered “invasive" only if it dramatically alters the ecosystem that it invades.
Whatever the meaning, this is a common problem. Some scientists view all invasions as potentially devastating to the ecosystems they invade; invasive species monopolize niches and compete for resources with native species, often driving endangered species to extinction, or decimating healthy populations of animal species. For this reason, conservation biologists focus a great deal of effort on both preventing the arrival and spread of invasive species, as well as their eradication.
Others believe that expanding resources for invasive species management programs is somewhat wasteful, given the fact that, ultimately, all species can be considered invasive. For example, wheat, corn, honeybees, cattle and chicken are all “invasive" to North America. Furthermore, there are a few scientists who believe that the arrival of an invader can actually be beneficial to the life history of a native species. The thought is this: an invasive species will compete with native species for resources and this competition will increase the rate of evolution and diversification of native species. In other words, some scientists see invasion as leading to a decrease in biodiversity, while others believe it could lead to an increase in species biodiversity.