Six ozone timing papers did not establish a rise in relative timing spread in a 2024 data release

We tested whether elevated ozone widens the relative spread of development and reproductive-onset times. We used 22 records from six papers published in 1997-2015 in a 2024 public data release. Five paper averages had positive corrected log coefficient-of-variation ratios. The equal-paper estimate was +16.93%, with a conditional 95% interval of -1.90% to +39.38%. Keeping at least ten units per treatment left three papers and gave -1.53%, with interval -26.80% to +32.46%. The uncorrected result was +20.78%. Combining two papers from one facility left the result uncertain. Region and publication-period cells lacked independent replication. The data do not establish a common rise in timing spread. Source errors can describe spread among experimental units or aggregates rather than individuals. Small samples, unknown error origins, shared controls and selected reporting limit inference. No climate effect or field mismatch was tested. Code, source hashes, aggregate results, checks and a figure are included.

ozone · ecological timing · development time · coefficient of variation · observation bias · small samples · null result