Letters to a Young Scientist

by Edward O. Wilson

Linnaeus had no idea, not even to the power of 10 (that is, whether 10,000, or 100,000, or 1,000,000), of the magnitude of his self-assigned task. He guessed that plant species, his specialty, would turn out to number around 10,000. The richness of the tropical regions were unknown to him. The number of known and classified plant species today is 310,000 and is expected to reach 350,000. When animals and fungi are added, the total number of species currently known is in excess of 1.9 million—and is expected to eventually reach 10 million or more. Of bacteria, the “dark matter” of living diversity, only about 10,000 kinds are currently known (in 2013), but the number is accelerating and is likely to add millions of species to the global roster. So, just as in Linnaeus’s time 250 years ago, most of life on Earth remains unknown. The still-deep pit of ignorance about