Why should we avoid extinction?

Anyone who thinks for a few moments will ask the question: are we worth preserving? I can imagine there will be some hackles raised by the possible implication that perhaps we are not worth preserving, but if you take a good, objective look at the way many animals live their lives and then look at what we are doing to our-selves and the world from which we emerged it's not easy to point to any clear cut way in which we are contributing constructively to the well-being of that world.
To point to the wonderful human accomplishments from the use of language to the music of Beethoven or Geoge Gershwin, from the early cave paintings to Leonardo or Michelangelo really doesn't count for much: the world out there isn't affected beneficially by all the finest artistic efforts Homo sapiens has created. (There is a way they could count, but I'll leave that for a future blog)
Just what, then, justifies our thinking that we are worth preserving? I have no clear idea how most people think about this and that is precisely the reason for raising the question in this way.
It is obvious that followers of any religion could be offended at my omitting of the accomplishments of any or all of the religions
that have existed, but it has always seemed to me that a great deal of the worst collective behaviour of us humans has been either initiated or supported by organised religions. It doesn't help to point to the source of inspiration for any or all of these
- the particular god or goddess, since they are not - at least in the minds of the believers - created by humans who therefore cannot take credit for any of the more beneficial aspects of the religion. Nor does it help to say, justifiably, that the murder and mayhem that happens is the result of individual human behaviour, for that could hardly be regarded as justifying our existence.
Any thoughts, anyone?
Any thoughts anyone?