# Mathematicians show how beetles can share a niche

## New equations help solve decades-old puzzle of why one species doesn’t always outcompete another

WASHINGTON, D.C. — Placing two species of flour beetle in the same jar of flour needn't always result in one species driving the other to extinction, as ecologists have thought. A new mathematical model presented January 5 at the annual Joint Mathematics Meetings shows how sometimes these two competing species can coexist.

The new research raises questions about a common assumption in ecology, the idea that only one species can survive in a specific ecological niche. Like similar species of flour beetles living in and eating the same flour, two species that share a niche ought to compete until one wipes out the other, according to the long-held theory.

But the theory assumes that no evolutionary changes occur in the beetles over a few dozen generations. By expanding the theory to include equations for subtle evolutionary changes even on such short time scales, mathematicians found that evolution can sometimes steer the two species toward coexistence.

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