Baldwin Effect

The Baldwin effect proposes a mechanism by which behaviors an organism learns, or traits it develops flexibly, during its own individual lifetime can, across many subsequent generations, influence the direction that later genetic evolution takes within the population, without requiring the direct inheritance of acquired characteristics that Lamarckian evolution proposes. American psychologist James Mark Baldwin proposed the idea around 1896, and closely similar ideas were put forward at roughly the same time by British psychologist Conwy Lloyd Morgan and American paleontologist Henry Fairfield Osborn, with the collection of related proposals sometimes grouped together under the term organic selection. Under the proposed mechanism, a learned or developmentally flexible trait that improves an individual's survival or reproduction in a new or changed environment can keep a population viable in that environment for long enough that natural selection subsequently favors any genetic variants that happen to make the same originally learned trait develop more automatically or innately, so that a capacity first acquired through learning can, over generations, come to resemble an inherited instinct without any direct transmission of the learned experience itself. The Baldwin effect remains a subject of ongoing theoretical interest within evolutionary biology, alongside continuing debate over how significant a role it actually plays in real-world evolutionary change.