Yep...this comes from the left, the environ(mental)ist and the "animals were here first crowd. (sometimes I wonder if they realize that They Too, would not exist).

But...ask yourself, your rationally interested self...what value would the earth serve without mankind? What possible purpose would it serve? Sure, the animals would have a place to live...but so what?
For that matter, what value would existence have without an awareness of it?

[Note: for those that don't know or never thought about it; Animals are, Yes, aware of their environment, but not aware of their own awareness...as such was the case for ancient man as well. But, we did have a strange and powerful curiosity about it all.]