Molecular signatures of resource competition: clonal interference favors ecological diversification and can lead to incipient speciation

Abstract

Microbial ecosystems harbor an astonishing diversity that can persist for long times. To understand how such diversity is generated and maintained, ecological and evolutionary processes need to be integrated at similar timescales, but this remains a difficult challenge. Here, we extend an ecological model of resource competition to allow for evolution via de novo mutation, focusing on large and rapidly adapting asexual populations. Through numerical and analytical approaches, we characterize adaptation and diversity at different levels and show how clonal interference – the interaction between simultaneously emerging lineages – shapes the eco-evolutionary dynamics. We find that large mutational inputs can foster diversification under sympatry, increasing the probability that phenotypically and genetically distinct clusters arise and stably coexist, constituting an initial form of community. Our findings have implications beyond microbial populations, providing novel insights about the interplay between ecology and evolution in clonal populations.

Redundancy-selection trade-off in phenotype-structured populations

“…For instance, the When multiple resource types are present, the different rates of consumption can be modelled as mutating quantitative traits. If an energetic constraint limits cells' ability of consumption due to metabolic trade-offs, then the population will evolve on a asymmetric trait space [68].…”