Mate choice for offspring performance: major benefits or minor costs?

There is considerable disagreement over whether or not gaining viability be nefits to offspring could be substantial enough to overcome the costs of fe male choosiness. A recent review suggested that the 'lek paradox' might be resolved by large indirect benefits as indicated by highly heritable orname ntal traits. We selected males of a wolf spider Hygrolycosa rubrofasciata i n relation to their sexual signalling rate (audible drumming). The estimate d correlated response in offspring viability was rather small (0.12 s.d.). However, it may be large enough if the costs of being choosy are small. In fact, females mate with better-than-average males just by responding passiv ely to a random drumming signal, and the active choice by females seemed to increase this benefit only slightly. In many mating systems, females obtai n better-than-average males as a consequence of intense male-male competiti on or because of the extraordinary variance in male signalling. The costs o f any additional choice may be so minor that female choice for honestly sig nalling males may evolve even with minute benefits in offspring viability. This may be the general solution to the lek paradox, as most studies report no apparent fitness benefits. Publication bias favouring statistically sig nificant results may have led to an overemphasis on the few studies with la rge effects.