A core assumption of sexual selection theory is that sexually selected weapons,specialized morphological structures used directly in male con-tests,can improve an individual's reproductive success but only if the ...A core assumption of sexual selection theory is that sexually selected weapons,specialized morphological structures used directly in male con-tests,can improve an individual's reproductive success but only if the bearer can overcome associated costs,the negative effects on the bear-er's fitness components.However,recent studies have shown that producing and wielding exaggerated weapons may not necessarily be costly.Rather,some traits can be selected for supporting,or compensating for,the expense of producing and wielding such exaggerated weapons.n the ant-mimicking jumping spider Myrmarachne gisti,exaggerated chelicerae are borne only by adult males and not females,showing sexual dimorphism and steep positive allometry with body size.Here,we determine the potential benefits of bearing exaggerated chelicerae during male contests and explore the potential for costs in terms of prey-capture efficiency and compensation between chelicera size and neighboring trait size.While males with longer chelicerae won most of their male-male contests,we found no significant differences in prey-capture effi-ciency between males and females regardless of whether prey was winged or flightless.Males'elongated chelicerae thus do not impede their efficiency at capturing prey.Furthermore,we found that the sizes of all neighboring traits are positively correlated with chelicera size,suggesting that these traits may be under correlational selection.Taken together,our findings suggest that M.gisti males armed with the exaggerated chelicerae that function as weapons win more fights at limited cost for performance in prey capture and compensate for neighboring structures.展开更多
基金supported by the grants from the National Natural Sciences Foundation of China(NSFC)(31572276,31872229,32270531,31801979)the Singapore Ministry of Education AcRF Tier 1(A-0004443-00-00,A-0008516-00-00).
文摘A core assumption of sexual selection theory is that sexually selected weapons,specialized morphological structures used directly in male con-tests,can improve an individual's reproductive success but only if the bearer can overcome associated costs,the negative effects on the bear-er's fitness components.However,recent studies have shown that producing and wielding exaggerated weapons may not necessarily be costly.Rather,some traits can be selected for supporting,or compensating for,the expense of producing and wielding such exaggerated weapons.n the ant-mimicking jumping spider Myrmarachne gisti,exaggerated chelicerae are borne only by adult males and not females,showing sexual dimorphism and steep positive allometry with body size.Here,we determine the potential benefits of bearing exaggerated chelicerae during male contests and explore the potential for costs in terms of prey-capture efficiency and compensation between chelicera size and neighboring trait size.While males with longer chelicerae won most of their male-male contests,we found no significant differences in prey-capture effi-ciency between males and females regardless of whether prey was winged or flightless.Males'elongated chelicerae thus do not impede their efficiency at capturing prey.Furthermore,we found that the sizes of all neighboring traits are positively correlated with chelicera size,suggesting that these traits may be under correlational selection.Taken together,our findings suggest that M.gisti males armed with the exaggerated chelicerae that function as weapons win more fights at limited cost for performance in prey capture and compensate for neighboring structures.
