| Comments |
P.4 left column bottom paragraph: "In addition to their effects on the structure of ecosystems, the flourishing of flesh-eating animals heralded a step-change in both biomass and biodiversity [primary source]. In the oceans today, for example, Butterfield [primary source] has estimated that animals may comprise as much as 80% of the biomass in the pelagic zone. Furthermore, with the evolution of animals, new coevolutionary selection pressures—in particular, arms races between the eaters and the eaten—appeared, accelerating the pace of macroevolution [ref 99]. At the same time, animal guts and external surfaces provided new niches for other life forms, both symbiotic and hostile." |