Evolvability Is Inevitable: Increasing Evolvability Without the Pressure to Adapt
This addresses a fundamental problem in evolutionary biology by offering a novel explanation for increasing evolvability, potentially impacting theories of evolution and adaptation.
The paper tackles the unresolved biological question of why evolvability increases over evolutionary time by proposing that it can occur without adaptation pressure, through heritable evolvability and niche founding, as demonstrated in simulated models.
Why evolvability appears to have increased over evolutionary time is an important unresolved biological question. Unlike most candidate explanations, this paper proposes that increasing evolvability can result without any pressure to adapt. The insight is that if evolvability is heritable, then an unbiased drifting process across genotypes can still create a distribution of phenotypes biased towards evolvability, because evolvable organisms diffuse more quickly through the space of possible phenotypes. Furthermore, because phenotypic divergence often correlates with founding niches, niche founders may on average be more evolvable, which through population growth provides a genotypic bias towards evolvability. Interestingly, the combination of these two mechanisms can lead to increasing evolvability without any pressure to out-compete other organisms, as demonstrated through experiments with a series of simulated models. Thus rather than from pressure to adapt, evolvability may inevitably result from any drift through genotypic space combined with evolution's passive tendency to accumulate niches.