the vast majority of organisms are not as unary as human society has become. we are so tightly coupled, so well connected to each other, that a cancer in one place threatens the whole. Cancer is fine for an individual from the perspective of a large collection, but a cancer in an individual when one individual is all there is would be catastrophic. the analogy we continue to use for growth in "the economy" abstracts out this fact.
yes, that's an important point. we are not a normal species and there is no point to pretend otherwise. every other sort faces a constant struggle for survival with their numbers being modulated by natural predators. Predators in turn get modulated when they overfeed on their prey. Our problem is that our prey is the entire planet.
i'd say that humanity is the least tightly coupled organism when it comes to survivability. when our ecosystem changes we are able to adapt better than any other organism.
