This talk will be presented via Zoom.
Cultural rescue: avoiding extinction with gene-culture coevolution.
Abstract: It is often suggested that the adaptability and success of human populations is a direct result of our sophisticated cultural abilities. Previously, we have suggested that in cases where lethal environmental shifts cause population decline, culture may be able to rescue an otherwise doomed population — in other words cause a ‘cultural population rescue’. Innovation and cultural transmission together might provide behavioural adaptations that could compensate for the detrimental effect of an environmental change. To the extent that such innovations could spread and be maintained through cultural transmission, such a process could indefinitely compensate for novel harsh environmental conditions.
However, such a scenario may be rare and culture might do more. Organisms with large body sizes and long generation times, like humans, are not typically thought to be able to undergo true ‘evolutionary rescue’, where compensatory genetic mutations arise and allow the demographic recovery of a declining population. As a consequence of long waiting times for beneficial mutations, where generation times are long, and population sizes are relatively small, populations are overwhelmingly likely to die out before such mutations arise and spread to high frequency. We suggest that where culture does not lead to a direct ‘cultural rescue’, it might nevertheless slow population decline providing time in which compensatory genetic mutations may arise. This mechanism seems plausible. However, the key to understanding the importance of culture in human population survival lies in describing how frequently such culturally-facilitated evolutionary rescues could occur and under what circumstances they are plausible, likely, or impossible.
In this talk I will describe a mathematical model of evolutionary rescue that allows for direct gene-culture interactive effects on biological fitness, and examine the probability of population rescue in the presence and absence of culture.
Meeting ID: 928 2643 6236