Rxivist logo

A novel cost framework reveals evidence for competitive selection in the evolution of complex traits during plant domestication

By Robin G Allaby, Chris J Stevens, Dorian Q Fuller

Posted 31 Oct 2020
bioRxiv DOI: 10.1101/2020.10.30.362236

Most models of selection incorporate some notion of environmental degradation where the majority of the population becomes less fit with respect to a character resulting in pressure to adapt. Such models have been variously associated with an adaptation cost, the substitution load. Conversely, adaptative mutations that represent an improvement in fitness in the absence of environmental change have generally been assumed to be associated with negligible cost. However, such adaptations could represent a competitive advantage that diminishes resource availability for others and so induces a cost. This type of adaptation in the form of seedling competition has been suggested as a mechanism for increases in seed size during domestication, a trait associated with the standard stabilizing selection model. We present a novel cost framework for competitive selection that demonstrates significant differences in behaviour to environmental based selection in intensity, intensity over time and directly contrasts to the expectations of the standard model. Grain metrics of nine archaeological crops fit a mixed model in which episodes of competitive selection often emerge from shifting optimum episodes of stabilizing selection, highlighting the potential prevalence of the mechanism outlined here and providing a fundamental insight into the factors driving domestication.

Download data

  • Downloaded 200 times
  • Download rankings, all-time:
    • Site-wide: 142,367
    • In evolutionary biology: 6,835
  • Year to date:
    • Site-wide: 106,460
  • Since beginning of last month:
    • Site-wide: 89,092

Altmetric data

Downloads over time

Distribution of downloads per paper, site-wide