Thats a shame, because you are simply showing how this: Is nothing more than your opinion (which is exactly why there will be nothing worth quoting found in anything remotely scientific - although I will be most intrigued if you do find something which deals with the issue). Sorry.
How so? I'm claiming that foodchains depict the feeding relationships between organisms(this is a fact)- beginning with greenplant organisms and ending with carnivores(also a fact). Human beings are not inherently carniverous(another fact), the fact that vegetarians exist backs this up- as does our sentiency and free will. Therefor we are not part of a foodchain, and are also not predators.