Population Bottleneck

palm tree poking above the top of many other trees

POPULATION BOTTLENECK. Washingtonia filifera, California fan palm.
North side of Stanford Bookstore.

In a population bottleneck, a population decreases in size for a period of time, then increases in size. In evolutionary models, a population’s size is often represented by the width of the tree branch used to represent the descent of the population. A bottleneck is represented by a branch that contracts in width and then expands again.

Photo: Noah Rosenberg, July 7, 2018