DOI: 10.5061/dryad.p8440
title: Data from: Microbial expansion-collision dynamics promote cooperation and coexistence on surfaces

description: Microbes colonizing a surface often experience colony growth dynamics
 characterized by an initial phase of spatial clonal expansion followed by
 collision between neighboring colonies to form potentially genetically
 heterogeneous boundaries. For species with life cycles consisting of
 repeated surface colonization and dispersal, these spatially-explicit
 “expansion-collision dynamics” generate periodic transitions between two
 distinct selective regimes, “expansion competition” and “boundary
 competition”, each one favoring a different growth strategy. We
 hypothesized that this dynamic could promote stable coexistence of
 expansion- and boundary-competition specialists by generating
 time-varying, negative frequency-dependent selection that insulates both
 types from extinction. We tested this experimentally in budding yeast by
 competing an exo-enzyme secreting “cooperator” strain
 (expansion-competition specialists) against non-secreting “defectors”
 (boundary-competition specialists). As predicted, we observed
 cooperator-defector coexistence or cooperator dominance with
 expansion-collision dynamics, but only defector dominance otherwise. Also
 as predicted, the steady-state frequency of cooperators was determined by
 colonization density (the average initial cell-cell distance) and cost of
 cooperation. Lattice-based spatial simulations give good qualitative
 agreement with experiments, supporting our hypothesis that
 expansion-collision dynamics with costly public goods production is
 sufficient to generate stable cooperator-defector coexistence. This
 mechanism may be important for maintaining public-goods
 cooperation-and-conflict in microbial pioneer species living on surfaces.
description: 2v9NospatialSimulation without spatial expansion-collision dynamics were ran with cells randomly shuffling among sites on the lattice every generation. Simulation were initiated with 2v9 dilution with initial cell-cell distance equals 3.2v8NospatialSimulation were run with cells randomly shuffling among sites on the lattice every generation. Simulation were initiated with 2v8 dilution with initial cell-cell distance equals 2. Note: Sheet 1 is a part of data for these simulations, Sheet 2 has entire date for this treatment and sheet 3 was used to generate the heatmap.2v7NospatialSimulation without expansion-collision dynamics were run with cells randomly shuffling among sites on the lattice every generation. Simulation were initiated with 2v7 dilution with initial cell-cell distance equals 1.2v4.9068NospatialSimulations without expansion-collision dynamics were ran with cells randomly shuffling among sites on the lattice every generation. Simulation were started with 0 initial cell-cell distance with a dilution of 2V4.9068.2v9_rareinvasionRare invasion simulations were ran with expansion-collision dynamics with initial cell-cell distance equals 3. Sheet 2 is the result for a single cooperator that invades a defector population. Sheet 3 is the result for a single defector that invades a defector population. Lines in Fig 6C (red for cooperator and green for defector) were drawn where the invasion probability first equals or exceeds 0.6, representing the boundary between invasion and non-invasion (a probability of 0.5 corresponds with selective neutrality) based on the yellow colored cells in the spreadsheet.2v8_rareinvasionRare invasion simulations were ran with expansion-collision dynamics with initial cell-cell distance equals 2. Sheet 2 is the result for a single cooperator that invades a defector population. Sheet 4 and sheet 5 are the result for a single defector that invades a defector population. Lines in Fig 6B (red for cooperator and green for defector) were drawn where the invasion probability first equals or exceeds 0.6, representing the boundary between invasion and non-invasion (a probability of 0.5 corresponds with selective neutrality) based on the yellow colored cells in the spreadsheet.2v7_rareinvasionRare invasion simulations were ran with expansion-collision dynamics with initial cell-cell distance equals 1. Sheet 2 is the result for a single cooperator that invades a defector population. Sheet 3 is the result for a single defector that invades a defector population. Lines in Fig. 6A (red for cooperator and green for defector) were drawn where the invasion probability first equals or exceeds 0.6, representing the boundary between invasion and non-invasion (a probability of 0.5 corresponds with selective neutrality) based on the yellow colored cells in the spreadsheet.2v9_nobenefitSimulations were ran with expansion-collision dynamics where initial cell-cell distance equals 3 and benefit equals 0.2v8_nobenefitSimulations were ran with expansion-collision dynamics where initial cell-cell distance equals 2 and benefit equals 0.2v7_nobenefitSimulations were ran with expansion-collision dynamics where initial cell-cell distance equals 1 and benefit equals 0.2v4.9068_nobenefitSimulations were ran with expansion-collision dynamics where initial cell-cell distance equals 0 and benefit equals 0.2v9_8neighbors/24neighborsSimulations (sheet 'parameter2', 'outgrid2', 's' and 'heatmap2') were ran with expansion-collision dynamics with initial cell-cell distance equals 3 and difusivity equals 1/9. Spreadsheet 'parameter3', 'outgrid3', 's' and 'heatmap' are results for the conditions where initial cell-cell distance is 3 and difusivity equals 1/25.2v9.xlsx2v8_8neighborsSimulations (spreadsheet 'parameter2', 'outgrid2', 's' and 'heatmap2') were ran with expansion-collision dynamics with initial cell-cell distance equals 2 and difusivity equals 1/9.2v9_1neighbor/12neighbors/16neighborsSimulations were ran with expansion-collision dynamics with initial cell-cell distance equals 3 and difusivity equals 1 (sheet '1_heatmap', 1/13 (spreadsheet '12_heatmap'), and 1/17 (sheet '16_heatmap').2v9.xlsx2v7_8neighborsSimulations were ran with expansion-collision dynamics with initial cell-cell distance equals 1 and difusivity equals 1/9.2v7_NoWeighingDispersalSimulations were ran with expansion-collision dynamics and the initial cell-cell distance equals 1 and the assumption of weighted dispersal was relaxed.2v8_NoWeighingDispersalSimulations were ran with expansion-collision dynamics and the initial cell-cell distance equals 2 and the assumption of weighted dispersal was relaxed.2v9_NoWeighingDispersalSimulations were ran with expansion-collision dynamics and the initial cell-cell distance equals 3 and the assumption of weighted dispersal was relaxed.cooperation1cdDVD_deterministic_evenlydistributed4Simulation code for conditions with expansion-collision dynamicscooperation1cdDVD_Noweighingdispersalv1Simulation code for expansion-collision dynamics with the assumption of weighted dispersal relaxed.cooperation1cdDVD_deterministic_evenlydistributed_rareinvasionSimulation code for rare invasion of a single cooperator or a single defector with expansion-collision dynamics.