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MALE REPRODUCTIVE COST. "A striking example involves Leucadendron xanthocomus in which males can produce up to 20 times more flowers than females. Bond and Maze (1999) found that the number of insect visits to male plants increased linearly with floral display size, but that increasing display size was associated with a higher probability of plant death." https://lnkd.in/ge7JD6J View in LinkedIn

STRENGTHENED SECOND RESPONSE. “This might explain why, according to historical documents, medieval plague mortality declined steeply between the initial outbreak in 1347–1351 and the second outbreak in 1361 and why mortality levels remained lower in subsequent plague outbreaks throughout the medieval and early modern periods.” https://lnkd.in/gGtSd3Y View in LinkedIn

FLORAL MALE-MALE COMPETITION. "The larger floral displays of males in many animal-pollinated dioecious species are usually interpreted as resulting from male–male competition for mates, but few cases are known where this is associated with the reduced survival of male plants as a result of viability selection." https://lnkd.in/ge7JD6J View in LinkedIn

FRAILTY REDUCTION. “In particular, given that reproductive-aged individuals with relatively high frailty (i.e. an individual's risk of death relative to other members of the population) were more likely to die during the Black Death than their age-peers with lower frailty, the epidemic might have affected genetic variation with respect to disease susceptibility or immune competence and thus, acted to reduce average levels of frailty in the surviving population.” https://lnkd.in/g2FqTm7 View in LinkedIn

FORM OVER FUNCTION? "Sexual selection is most obvious in animals when it favours the evolution of extravagant male displays that enhance mating success at the expense of reduced viability." https://lnkd.in/ge7JD6J View in LinkedIn

NATURAL SELECTION. “By targeting frail people of all ages, and killing them by the hundreds of thousands within an extremely short period of time, the Black Death might have represented a strong force of natural selection and removed the weakest individuals on a very broad scale within Europe.” https://lnkd.in/g2FqTm7 View in LinkedIn

RESOURCE DIFFERENTIATION. "Sexual dimorphism in physiology and reproduction can result in the sexes requiring different resources from the environment, a phenomenon knows as the ‘Jack Sprat effect’." https://lnkd.in/ge7JD6J View in LinkedIn

IMPACT OF LATITUDE. "Based on a survey of 116 populations at the northern range limit of this species, the authors found a significant decline in the frequency of females with increasing latitude." https://lnkd.in/ge7JD6J View in LinkedIn

"GROWING SEASON LENGTH may also differentially affect the sexes, especially in northern latitudes where a shorter growing season may limit opportunities for females to mature seed successfully. A latitudinal survey of sex ratios of Sagittaria latifolia in eastern North America revealed patterns consistent with the hypothesis that females are more sensitive to conditions that limit their reproductive activities." https://lnkd.in/ge7JD6J View in LinkedIn

DEGREE OF DIMORPHISM. "These predictions were recently confirmed in comparative analyses of the life-history correlates of dioecy, in which male-biased sex ratios were associated with woody growth forms and fleshy fruits. Differences in the degree of sexual dimorphism in reproductive expenditure may therefore be influential in shaping patterns of sex ratio variation among angiosperm species." https://lnkd.in/ge7JD6J View in LinkedIn