Very few studies have experimentally assessed the evolutionary effects of species interactions within the same trophic level. Here we show that when Serratia marcescens evolve in multispecies communities, their growth rate exceeds the growth rate of the bacteria that evolved alone, whereas the biomass yield gets lower. In addition to the community effects per se, we found that few species in the communities caused strong effects on S. marcescens evolution. The results indicate that evolutionary responses (of a focal species) are different in communities, compared to species evolving alone. Moreover, selection can lead to very different outcomes depending on the community structure. Such context dependencies cast doubt on our ability to predict the course of evolution in the wild, where species often inhabit very different kinds of communities.
Data for different clones of Serratia marcescens evolving in different multi species communities, or alone, under high or low resource concentration. Measurements for growth rate and yield were done in two resource concentrations. Columns in the data: Population: identity of population/microcosm where clones have evolved
Clone: id number of isolated clone within population
NB: measurement concentration where 25 % stands for low nutrient broth concentration and 100% for high.
Ctreat: community treatment 1 stands for evolution alone, and 2 evolving in community.
Rtreat: Resource evolution treatment 25 % stands for low nutrient broth concentration and 100% for high.
Rmax: maximum growth rate OD h-1
K: maximum attained biomass (OD)
Inoculum: how much biomass of bacteria were pipetted in the wells prior to measurement.
Ncaps: presence absence information of Novosophingobium capsulatum
Pchloro: presence absence information of Pseudomonas chlororaphis
Pputida: presence absence information of Pseudomonas putida
Ecoli: presence absence information of E. Coli
Eaerog: presence absence information of Enterobacter aerogenes
Ladecar: presence absence information of Leclercia adecarboxylata
DummyNcaps: presence absence information of Novosophingobium capsulatum
DummyPchloro: presence absence information of Pseudomonas chlororaphis
DummyPputida: presence absence information of Pseudomonas putida
DummyEcoli: presence absence information of E. Coli
DummyEaerog: presence absence information of Enterobacter aerogenes
DummyLadeca: presence absence information of Leclercia adecarboxylat