What does this equation mean?

Suppose further that among the trait-positive horizontally exposed models, 70 percent produce a response diverging from the seeded canonical form beyond the declared threshold, $\mu_H$=0.70 , against 15 percent for the vertically exposed group, $\mu_V$=0.15 : horizontal transmission would be lossier, consistent with an indirect channel and with Mesoudi and Whiten’s finding that transmission-chain experiments on human cultural information typically show cumulative drift across successive links rather than the stable replication a simple copying model would predict [ 14 ] . And suppose a curation pass applied before the horizontally exposed artifact reached its downstream trainer moved the trait’s prevalence from $p_{\mathrm{pre}}$=0.25 to $p_{\mathrm{post}}$=0.55 , curators keeping the more verbose, apparently more careful outputs that happened to carry the trait, giving s=$\ln$$\left(\frac{0.55/0.45}{0.25/0.75}\right)$$\approx$1.30 : a positive selection coefficient, meaning the pipeline itself, not only the source model, pushed the trait toward survival. None of these six numbers has been measured. They exist to give the sealed-lineage trial proposed below something concrete to confirm or embarrass.