Surprisingly Low Limits of Selection in Plant Domestication

Area of Science:

• Plant domestication genetics
• Evolutionary modeling
• Archaeological science

Background:

• The domestication of plants is a key event in human history, yet the genetic and evolutionary processes involved remain debated.
• Understanding the number of genes under selection and the pace of domestication is crucial for interpreting archaeological findings.

Purpose of the Study:

• To estimate the number of loci under selection during plant domestication.
• To investigate the impact of selection on plant adaptability and its relation to historical agricultural patterns.

Main Methods:

• Utilized an individual-based model incorporating assumptions from Haldane and Maynard Smith.
• Simulated cultivation regimes with selection strengths derived from the archaeological record.
• Assessed the robustness of findings against factors like genetic variation, gene flow, and threshold selection.

Main Results:

• Estimated that 50-100 loci are the maximum under selection in a cultivation regime.
• Demonstrated that this finding is robust across different modeling assumptions and population rescue mechanisms.
• Showed that selective sweeps reduce plant adaptability to new environments.

Conclusions:

• Plant domestication likely involved a limited number of genetic loci.
• The reduced adaptive capacity resulting from selective sweeps may explain the historical frequency of agricultural package expansion failures and Neolithic collapses.