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Table 4 Model parameters and notation

From: The role of the ecological scaffold in the origin and maintenance of whole-group trait altruism in microbial populations

Parameter

Interpretation

Values used

\({R}_{in}\)

Nutrient influx per group per generation

\(5\, \mathrm{or}\, 50\)  

\(\delta\)

The fitness deficit suffered by A-type cells

\(0.98\, \mathrm{or}\, 1.00\)  

\({D}_{min}\)

The probability of death per cell per generation in an A-type population

\(0.05\)

\({D}_{max}\)

The probability of death per cell per generation in an S-type population

\(0.30\)

\({P}_{mut}\)

The probability of a “switch” mutation per cell per generation

\({10 }^{-6}\)

\(\Delta g\)

Number of generations between sets of dispersal events

\(1, 25, 50, 100\)

\(p\)

The proportion of cells drawn from a donor group for form a migration propagule

\(0.25\)

\({N}_{A}={N}_{cap}(\pi =1)\)

The number of cells in an A-type group at birth–death equilibrium

\({R}_{in}{/D}_{min}\)

\({N}_{S}={N}_{cap}(\pi =0)\)

The number of cells in an S-type group at birth–death equilibrium

\({R}_{in}{/D}_{max}\)

Notation

Interpretation

\({w}_{A}\left(\pi \right)\)

The fitness of an A-type cell in a population in which the proportion of A-type cells is \(\pi\)

\({w}_{S}\left(\pi \right)\)

The fitness of an S-type cell in a population in which the proportion of A-type cells is \(\pi\)

\(cR(\pi )\)

The proportion of nutrient influx \({R}_{in}\) consumed by the subpopulation of A-type cells within any population or group

\({P}_{AS}\)

Probability that an A-type population will transition to an S-type population by selection following an A-to-S-type mutation in a single A-type cell

\({P}_{SA}\)

Probability that an S-type population will transition to an A-type population by drift following an S-to-A-type mutation in a single S-type cell

\({\pi }_{AS}\)

The expected proportion of A-type cells in a recipient S-type group after it has received a migration propagule from an A-type donor

\({\pi }_{SA}\)

The expected proportion of A-type cells in a recipient A-type group after it has received a migration propagule from an S-type donor

\({W}_{A}\)

The nominal fitness of an A-type group in a metapopulation with dispersal by migration

\({W}_{S}\)

The nominal fitness of an S-type group in a metapopulation with dispersal by migration

\({F}_{A}\)

The proportion of A-type groups in a metapopulation

\({F}_{S}\)

The proportion of S-type groups in a metapopulation