Month: September 2022

MALE BIAS. "A recent survey of flowering sex ratios among angiosperm families revealed that about half showed significant deviations from equality, with male bias almost twice as common as female bias." https://lnkd.in/ge7JD6J View in LinkedIn

HIGHER FEMALE MORTALITY. "The frequent occurrence of male-biased sex ratios is likely to be associated with the greater reproductive investment of females, as this commonly results in the earlier onset and more frequent flowering of males and the greater mortality of females." https://lnkd.in/ge7JD6J View in LinkedIn

SEXUAL SEGREGATION. "Many sexually dimorphic characters, including both vegetative and flowering traits, are associated with differences in the costs of reproduction, which are usually greater in females, particularly in longer-lived species. These differences can influence the frequency and distribution of females and males across resource gradients and within heterogeneous environments, causing niche differences and the spatial segregation of the sexes." https://lnkd.in/ge7JD6J View in LinkedIn

FRUIT PLANT SEX BIAS. "This observation leads to the prediction that long-lived dioecious species that experience repeated episodes of reproduction should be more likely to develop male-biased sex ratios. Such effects may be especially strong in species with a large maternal investment in costly fleshy fruits, a common correlate of dioecy." 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

"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

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

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

NICHE ALTERATION. "The possibility that the sexes modify their ecological niches had not been considered in any detail until recently, especially with regard to future offspring performance." https://lnkd.in/ge7JD6J View in LinkedIn

NICHE ALTERATION DATA. "By growing plants of M. annus in soil previously occupied by females or males, Sánchez-Vilas and Pannell (2010) found that plants grown in soil in which females had previously grown were significantly smaller in terms of total biomass than those grown in soil previously occupied by males." https://lnkd.in/ge7JD6J View in LinkedIn