You can either stop reading now because that’s the answer to the question, or you can continue and find out a little more detail.
I’ve just had an extremely pleasant experience reading John Terborgh‘s latest Perspective in PNAS. You know the kind of paper you read that (a) makes you feel smart, (b) confirms what you already think, yet informs you nonetheless, and (c) doesn’t take three days to digest? That’s one of those.
Toward a trophic theory of species diversity is not only all of those things, it’s also bloody well-written and comes at the question of ‘Why are there so many species on the planet when ecological theory can’t seem to explain how?’ with elegance, style and a lifetime of experience. I just might have to update my essential-ecology-papers list. If I had to introduce someone to 60 years of ecological theory on biodiversity, there’s no better place to start.