Recent theory predicts that increased phenotypic plasticity can facilitate adaptation as traits respond to selection. When genetic adaptation alters the social environment, socially mediated plasticity could cause co-evolutionary feedback dynamics that increase adaptive potential. We tested this by asking whether neural gene expression in a recently arisen, adaptive morph of the field cricket Teleogryllus oceanicus is more responsive to the social environment than the ancestral morph. Silent males (flatwings) rapidly spread in a Hawaiian population subject to acoustically orienting parasitoids, changing the population's acoustic environment. Experimental altering crickets’ acoustic environments during rearing revealed broad, plastic changes in gene expression. However, flatwing genotypes showed increased socially mediated plasticity, whereas normal-wing genotypes exhibited negligible expression plasticity. Increased plasticity in flatwing crickets suggests a coevolutionary process coupling socially flexible gene expression with the abrupt spread of flatwing. Our results support predictions that phenotypic plasticity should rapidly evolve to be more pronounced during early phases of adaptation.
Bibliographical noteFunding Information:
We thank John Kenny for advice on RNA-seq and Nanos-tring experimental designs and execution. David Forbes and Audrey Grant provided assistance with cricket maintenance and Tanya Sneddon provided general wet lab support. Sequencing and bioinformatics was supported by the NERC Biomolecular Analysis Facility at the University of Liverpool (NBAF717), and Richard Gregory assisted during initial sequence data processing. Emilie C. Snell-Rood provided useful suggestions for the manuscript. This work was funded by Natural Environment Research Council grants (NE/ I027800/1, NE/G014906/1, NE/L011255/1).
- Teleogryllus oceanicus
- genetic assimilation
- genomic invasion
- phenotypic plasticity
- rapid evolution
- social environment