EVOLUTION OF LEARNING IN FLUCTUATING ENVIRONMENTS: WHEN SELECTION FAVORS BOTH SOCIAL AND EXPLORATORY INDIVIDUAL LEARNING
Version of Record online: 25 DEC 2007
©2008 The Author(s). Journal compilation © 2008 The Society for the Study of Evolution.
Volume 62, Issue 3, pages 586–602, March 2008
How to Cite
Borenstein, E., Feldman, M. W. and Aoki, K. (2008), EVOLUTION OF LEARNING IN FLUCTUATING ENVIRONMENTS: WHEN SELECTION FAVORS BOTH SOCIAL AND EXPLORATORY INDIVIDUAL LEARNING. Evolution, 62: 586–602. doi: 10.1111/j.1558-5646.2007.00313.x
- Issue online: 25 DEC 2007
- Version of Record online: 25 DEC 2007
- Received August 21, 2007Accepted December 3, 2007
- Cumulative culture;
- exploratory individual learning;
- integer phenotype space;
- overlap of environmental states
Cumulative cultural change requires organisms that are capable of both exploratory individual learning and faithful social learning. In our model, an organism's phenotype is initially determined innately (by its genotypic value) or by social learning (copying a phenotype from the parental generation), and then may or may not be modified by individual learning (exploration around the initial phenotype). The environment alternates periodically between two states, each defined as a certain range of phenotypes that can survive. These states may overlap, in which case the same phenotype can survive in both states, or they may not. We find that a joint social and exploratory individual learning strategy—the strategy that supports cumulative culture—is likely to spread when the environmental states do not overlap. In particular, when the environmental states are contiguous and mutation is allowed among the genotypic values, this strategy will spread in either moderately or highly stable environments, depending on the exact nature of the individual learning applied. On the other hand, natural selection often favors a social learning strategy without exploration when the environmental states overlap. We find only partial support for the “consensus” view, which holds that individual learning, social learning, and innate determination of behavior will evolve at short, intermediate, and long environmental periodicities, respectively.