Every species that exists on the earth has a reason to be there. Not a reason as in “because God wanted it that way”, but a reason as in they are fulfilling an evolutionary niche. Any new species that appears in an ecosystem contributes something in some way to that ecosystem. If they don’t, the ecosystem becomes impoverished and unable to support them, and they begin dying off until equilibrium is restored. If a species is removed from the ecosystem, then everything goes out of whack, and starts to affect neighboring ecosystems.
Right now in New Mexico, a major environmental concern is the Rio Grande Silvery Minnow. A small, unassuming fish, the minnow used to range pretty much all the way up and down the Rio Grande’s length. Now it is confined to a small section of the river that has the nasty tendency to dry up in the summer. They can’t go upstream to spawn because of flood control dams, and attempts to reintroduce them to other parts of the river have failed- they always end up in that same stretch. Now, in many spots on the river, there are no fish at all. The silvery minnow is pretty much the mid-Rio Grande’s last gasp as a balanced ecosystem. If it disappeared, who knows what would happen? Perhaps the river would become choked with algae, and become useless as a supply of drinking water. Perhaps the birds that feed on the minnow would also vanish from the region.
To answer the OP, clearly, all species are not quite as harmless to us as your average minnow. The guinea worm, which someone on the other thread says only inhabits humans, is a good example of this. Since the ecosystem we’re talking about is the interior of the human body, well, not having any more guinea worms about would obviously be beneficial. As was stated, they’re parasites. They take from the ecosystem, and give nothing back. However, the argument could be made that the guinea worm plays a vital role in keeping the human population down. I believe I’ll leave this to a debate on overpopulation.
I was going to close by stating that while no species, including our own, has the right to exist, it would be in everyone’s interest to see to it that none is eliminated without some very serious thought as to the consequences. But then I thought, what are rights, anyway? We here in America have the right to speak freely, choose our own religions, keep and bear arms, petition our government for redress of grievances, etc. Why do we have these rights? Because, in the long run, it is best for everyone that we do. Perhaps the question of species rights could be visualized in similar terms. If we don’t eliminate them, their absence doesn’t cause us to choke on our own excrement, or something to that effect.
As a postscript, I would like to add that viruses mutate so quickly that none would be missed for long if they were eradicated.
Heck is where you go when you don’t believe in Gosh.
