Abstracts (first author)
Genetic architecture promotes the evolution and maintenance of cooperation: the evolutionary constraint of coding overlaps on functionally unrelated genesPDF
When cooperation has a direct cost and an indirect benefit, a selfish behavior is more likely to be selected for than an altruistic one. Kin and group selection do provide evolutionary explanations for the existence of stable populations of cooperators in nature, but we still lack the full understanding of the genomic mechanisms that can prevent cheater invasion. We used Aevol, an agent-based, in silico genomic platform to evolve populations of digital organisms that compete, reproduce, and cooperate by secreting a costly public good. We found that populations of phenotypically equal cooperating individuals often have very different abilities to resist cheater invasion. To understand the underlying mechanisms, we performed bio-inspired genomics analysis by determining and comparing the locations of metabolic and secretion genes, as well as the relevant promoters and terminators. We found that populations of cooperators characterized by the strong association between metabolic and secretion genes (promoter sharing, overlap via frame shift or sense-antisense encoding) were more robust to cheater invasion than ones where such association was weak. We performed mutation analysis of the evolved individuals and determined that the accessibility of mutations decreasing cooperation without decreasing overall fitness was negatively correlated with the amount of operons and overlap between secretion and metabolism. Effectively, cooperation evolved to be protected and robust to mutations through overlapping genetic architecture, especially when cooperation was costly. Due to operon sharing and gene overlap, even when mutations that eliminate cooperation appear, they are likely to be selected against due to their simultaneous and direct negative effect on fitness. Our results uncover an important genetic mechanism for the evolution and maintenance of cooperation, and suggest promising methods for preventing loss of genes introduced into biological synthetic organisms.