Quasireplication and the contract of error: Lessons from sex ratios, heritabilities and fluctuating asymmetry

Selective reporting-e.g., the preferential publication of results that are statistically significant, or consistent with theory or expectation-present s a challenge to meta-analysis and seriously undermines the quest for gener alizations. Funnel graphs (scatterplots of effect size vs. sample size) hel p reveal the extent of selective reporting. They also allow the strength of biological effects to be judged easily, and they reaffirm the value of gra phical presentations of data over statistical summaries. Funnel graphs of p ublished results, including: (a) sex-ratio variation in birds, (b) held est imates of heritabilities, and (c) relations between fluctuating asymmetry a nd individual attractiveness or fitness, suggest selective reporting is wid espread and raise doubts about the true magnitude of these phenomena. Quasi replication-the "replication" of previous studies using different species o r systems-has almost completely supplanted replicative research in ecology and evolution. Without incentives for formal replicative studies, which cou ld come from changes to editorial policies, graduate training programs, and research funding priorities, the contract of error will continue to thwart attempts at robust generalizations.