Baldwin effect

James Mark Baldwin and others suggested that an organism's ability to learn new behaviours (e.g. to acclimatise to a new stressor) will affect its reproductive success and will therefore have an effect on the genetic makeup of its species through natural selection.

As the historian of science Robert Richards explains:[3] If animals entered a new environment—or their old environment rapidly changed—those that could flexibly respond by learning new behaviours or by ontogenetically adapting would be naturally preserved.

[4][5] In the words of the philosopher of science Daniel Dennett:[6] Thanks to the Baldwin effect, species can be said to pretest the efficacy of particular different designs by phenotypic (individual) exploration of the space of nearby possibilities.

This new version included an explicit role for the social in shaping subsequent natural change in humans (both evolutionary and developmental), with reference to alterations of selection pressures.

[4] In 1942, the evolutionary biologist Julian Huxley promoted the Baldwin effect as part of the modern synthesis, saying the concept had been unduly neglected by evolutionists.

[22] Still, David Depew observed in 2003, "it is striking that a rather diverse lot of contemporary evolutionary theorists, most of whom regard themselves as supporters of the Modern Synthesis, have of late become 'Baldwin boosters'".

[12] These are typically evolutionary psychologists who are searching for scenarios in which a population can get itself by behavioral trial and error onto a "hard to find" part of the fitness landscape in which human brain, language, and mind can rapidly coevolve.

[25][26][27] The Baldwin effect has been confused with, and sometimes conflated with, a different evolutionary theory also based on phenotypic plasticity, C. H. Waddington's genetic assimilation.