Researchers say evolution doesn't turn random after adaptation - it keeps drifting

A team in Israel argues that adapting successfully to an environment does not necessarily leave a species in a state of purely random change. Even then, evolutionary change can keep trending in one direction.

Using a mathematical model, Technion Israel Institute of Technology biologists Naama Brenner and Razi Fachareldeen found that evolution can remain patterned even without any newly introduced selective pressure.

In Popular Mechanics , the finding is presented as a challenge to the classic view that once a population is already well matched to its surroundings, later changes are mostly a matter of chance.

Their analysis depends on the idea of a fitness landscape, a framework geneticist Sewall Wright introduced in the 1930s. In that picture, evolution plays out across peaks and valleys, with higher ground standing for trait combinations that improve survival and reproduction.