To better understand what we observe in the world, we need to know more about what is absent. This is a hypothesis of Estonian ecologists Meelis Partel, Robert Szava-Kovats, and Martin Zobel, who call the portions of species pools missing from study sites "dark diversity."
Think of it as analogous to dark matter, the invisible mass that physicists hypothesize accounts for the bulk of matter-energy in the vast expanse of space. Dark diversity serves a similar function: "Just as dark matter is important to understanding the structure of galaxies, dark diversity is necessary to understand ecosystems," Partel explains.
The researchers, from the Institute of Ecology and Earth Sciences at the University of Tartu, described their hypothesis in the journal Trends in...