h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I have no idea how many creatures we destroy without knowing about it. We only know so much about our world...I don’t think we’re quite aware of what a delicate balance it is yet.

"do you consider their loss really a great tragedy?"
Just because we humans didn't know about something, doesn't mean it wasn't important or amazing, or any less worthwhile.

"If the dolphin was not suited to survive in our modern world, could its loss be attributed to natural selection?"
No. What we're capable of doing goes beyond natural selection. Nature has balance; ecosystems that can adapt in the face of disease or overcrowding; that’s natural selection.
Our modern world is designed only on the understanding of the world we have so far, and we’re less inclined to adapt unless it will benefit us. We’re pretty much making this up as we go.

As for balancing economy with the environment, that's a tough one. My personal opinion is that we will eventually have to restructure our lives, our economies and our cultures around what we and the rest of the world *need* as opposed to what we *want*, if we're to keep something resembling the world that we have. But that would be a huge and complicated shift in both action and attitude.
Whether we’ll be willing (and able) to plan for the future and make such a big change, well your guess is as good as mine. Things seem to be going in that direction, albeit agonisingly slowly. Solar panels and organic food is just the beginning, folks.

To me the snag is that the human race doesn't know enough yet. Species are created and they become extinct- that has always been the case, but the problem is that humans now seem to have a far larger impact on the world and it's ecosystems than any other animal... a responsibility we just weren’t expecting.
So we now have to take responsibility for the impact we have on the planet- we must stop ourselves from accidentally wiping out plants and animals and habitats just because we rather like eating tuna, or deciding to cut down part of the rainforests to have more land to farm animals. (Yes! I know it's more complicated then that!)
But where does it end? The way we’re going it seems like we have to changing things now, and protect what we have or we’ll keep loosing important and irreplaceable species.
But we can't stop time and make the cycle of life and death stand still. Even if we could stop all extinction, would that be any more responsible than what we're doing now?
So how do we get the balance right?
When are we going to answer these questions with answers, rather than more questions?

(My apologies for the long ramble, I gues I got carried away.)