Dozens of species compete for a handful of resources in open water — none should win
A single litre of ocean or lake water can hold dozens of competing phytoplankton species, all needing essentially the same few things: light and a handful of dissolved nutrients. Ecological theory says that when species compete for the same limited resources in a stable environment, the best-adapted one should eventually drive the rest extinct. So why doesn't a single 'winning' species dominate every patch of open water?
Reveal the answer
Ecologist G. Evelyn Hutchinson named this 'the paradox of the plankton' in 1961 and proposed that real environments never stay stable long enough for any one competitor to finish the job — constantly shifting light, turbulence and seasons keep resetting the competition before a single winner can emerge, letting dozens of species persist in an endless, unfinished race instead of a settled outcome.
— G. Evelyn Hutchinson, The Paradox of the Plankton — The American Naturalist, vol. 95, 1961