An empirical test of Baker’s law: Dispersal favors increased rates of self-fertilization

Baker’s law is the observation that recently dispersed populations are more likely to be self-fertilizing than populations at the range core. The explanatory hypothesis is that dispersal favors self-fertilization due to reproductive assurance. Caenorhabditis elegans nematodes reproduce via either self-fertilization or outcrossing and frequently disperse in small numbers to new bacterial food sources. While C. elegans males facilitate outcrossing, males and outcrossing are rare in natural C. elegans populations. Here, we use experimental evolution to test if frequent dispersal selects for the invasion of self-fertilization into predominantly outcrossing populations. C. elegans dispersal often occurs in the dauer alternative life stage. Therefore, we tested the effects of dispersal on rates of self-fertilization in populations exposed to dauer-inducing conditions and populations maintained under standard lab conditions. Overall, we found that populations required to disperse to new food s..., , , # Dispersal favors self-fertilization [https://doi.org/10.5061/dryad.5qfttdzgb](https://doi.org/10.5061/dryad.5qfttdzgb) ## Description of the data and file structure Data files are named after experiments described in manuscript. **initial fecundity assays.xlsx:** Fecundity assays for signs of inbreeding depression described in the NEMATODE STRAINS AND REPRODUCTIVE MODE methods section. **patch dispersal assays.xlsx:** Assays for distribution of worms across bacterial patches as described in the DISPERSAL TREATMENTS methods section. **dispersal power analysis.xlsx:** beta values generated by power analysis for patch distribution assay as described in the DISPERSAL TREATMENTS methods section. **movement between patches.xlsx:** Assay for movement of worms between bacterial patches as described in the DISPERSAL TREATMENTS methods section. **dispersal fecundity assays.xlsx:** Assays of the effect of dispersal and mating system on worm fecundity, as described in the FECUNDITY ASSA...