It is also easy to overlook the services that ecosystems provide humanity. they enrich the soil and create the very air we breathe. without these amenities, the remaining tenure of the human race would be nasty and brief. the life-sustaining matrix is built of green plants with legions of microorganisms and mostly small, obscure animals—in other words, weeds and bugs. such organisms support the world with efficiency because they are so diverse, allowing them to divide labor and swarm over every square meter of the earth’s surface. they run the world precisely as we would wish it to be run, because humanity evolved within living communities and our bodily functions are finely adjusted to the idiosyncratic environment already created. the author tries to persuade the reader to agree with his claim about the importance of ecosystems by providing facts. presenting statistics. restating his claim. using deductive reasoning.