Biocompatibility: a criterion for conservation

A rich ecosystem like a tropical rain forest contains three categories of organisms: (1) the sustainer green photosynthetic plants of all growth forms, their pollinators, seed dispersers, and protectors from injurious insects, and mostly obscure decomposers of dead matter that replenish the soil’s fertility; (2) the associates or "guests", a diverse group that appears to be neither necessary for the maintenance of the ecosystem nor injurious to it; and (3) the "enemies", predators great and small, parasites external and internal, pathogens, etc. that torture, mutilate, or destroy members of the first two categories, which coexist harmoniously, rarely injuring one another. I urge conservationists to give preferential treatment to these compatible categories, ceasing to apply inadequate resources to the protection or increase of members of the third category, if nor trying to eliminate some of them. By promoting biocompatibility, or compatible biodiversity, instead of biodiversity of undefined limits, we might make a more harmonious, productive, and enjoyable natural world.