JIM HARRISON, PHOTOGRAPHER HARVARD NEWS OFFICE
One of the fundamental questions of biology is the amount and full nature of biodiversity on Earth. It should be worrisome to all that 250 years after Carl Linnaeus introduced the practice of binomial nomenclature and articulated the goal of identifying all species of organisms, we still have accounted for only a tiny fraction of the whole. The number of living species thus far discovered is approximately 1.9 million.[1. A.D. Chapman et al., Numbers of Living Species in Australia and the World, 2nd ed., Toowoomba, Australia: Australian Biodiversity Services, 2009.] The true number of living eukaryotic species (all plants, animals, and microorganisms above the level of bacteria and archaeans), known plus unknown, is at least four times that number,[2. C.Mora et al., “How many species ...
