Genomic parallelism defines repeated evolution of an inducible offense

The study for which these data were generated is summarized as follows: A common developmental response to resource competition is an inducible offense, which involves the facultative predation of competitors. At its extreme, this response involves the development of alternative phenotypic morphs, or polyphenism. However, how polyphenism evolves to meet ecological challenges, such as competitor species, is unknown. Using replicated experimental evolution, during which starved nematodes could consume heterospecific competitors, we investigated whether induction of a predatory morph could evolve and how generalizable the genetic basis of this change is. Fifty generations of evolution across multiple populations resulted in parallel changes in higher morph induction and parallel genomic responses, including repeated selection for a specific transcription-factor binding-site variant. In tandem, we artificially selected directly for tooth morphology and drove the predatory morph near fixation. That trait-specific selection promoted greater changes in predatory morph induction than experimental evolution indicates that polyphenism evolution is balanced by selection for whole-organism performance. Our results thus describe the predictability by which a resource polyphenism evolves amid scarce resources.

These data include phenotypic and intermediate genome-wide data for analyzing shifts in phenotype production over generations between environments, effects of mutation on phenotype production, and divergence in allele frequencies among populations.

Methods
These data correspond to phenotypic and genetic data from an experimental evolution and artificial selection study exploring the genetic bases of polyphenism evolution in a new environment. Primary data include counts of predatory and microbivore feeding morphs over generations, downstream analysis of pool-sequencing data from 54 populations of nematodes, functional phenotype and genetic information of mutant lines, and code for processing and analyzing the data.