Perhaps this is arrogance on humanity's part, but humans are considered apex predators simply because they are able to overcome their physical limitations in a way animals cannot. We, as a species, define ourselves on our ability to circumvent the the natural order of the animal kingdom.
Humankind will naturally come up short if we focus on sheer physical attributes - we're incapable of the brute strength of elephants, for example. Our speed is nothing compared to the humble antelope, let alone the glorious cheetah. Our physical shortcomings relative to other denizens in the animal kingdom is not up for question. But it's our ability to manipulate the environment until our shortcomings are irrelevant that makes us powerful predators. In a hand to claw fight, we'd naturally die out if we were all pitted against lions. But our cognitive sophistication has allowed us to develop external ways of dealing with the lion: weapons. We're not unique in our use of weapons and tools, but no other animal comes close to our level. We use our grasp of technology to allow us to survive in 'arenas' where we would surely die otherwise. The Sahara, Antarctica, Space! Literally outside our own planet!
We all know this, though.
Also, we're almost unique in our ability to domesticate other species. Only ants keep us from claiming the title of the sole species capable of domestication. It's really quite alarming when you think about it - we've taken a species and through selective breeding, turned it into something that serves us and needs us. For the meanwhile, that is. If humans were to die out tomorrow, domesticated animals would (hopefully) adapt to their lack of a master species and not die out with us. But anyway. Our unrivaled arrogance has allowed to take a species and decide that it is best used if it is used to support us or provide us with companionship. We're quite a manipulative species, really.
While the thought of humans being the supreme species is nothing short of narcissism, we are undoubtedly very powerful.
Humans also have another asset which is a conscious mind that can overcome natural behaviors. Where all animals and creatures behave based on cause and effect, humans can step back and have a different effect for the same cause.
I don't have anything to add to this, but I thought it was a wonderful point.