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DIOECY. “Dioecious plants, however fertilised, have a great advantage over other plants in their cross-fertilisation being assured. But this advantage is gained ... with some risk ... of their fertilisation occasionally failing. Half the individuals, moreover, namely, the males, produce no seed, and this might possibly be a disadvantage... dioecious plants cannot spread so easily as monoecious and hermaphrodite species, for a single individual, which happened to reach some new site, could not propagate its kind.” https://lnkd.in/dUmPa47 View in LinkedIn

RISKS OF DIOECY. “Separating sexual function between different individuals carries risks, especially for sedentary organisms. Nevertheless, many land plants have unisexual gametophytes or sporophytes.” https://lnkd.in/dUmPa47 View in LinkedIn

DIOECY IN ANIMALS. “Dioecy may also describe colonies, such as the colonies of Siphonophorae (Portuguese man-of-war), which may be either dioecious within a species or monoecious. Dioecious colonies contain members of only one sex, whereas monoecious colonies contain members of both sexes. Most animal species are dioecious (gonochoric).” https://lnkd.in/dKd4E5r View in LinkedIn

DIOECY DEFINED. “Dioecy (Greek: διοικία "two households"; adjective form: dioecious) is a characteristic of a species, meaning that it has distinct male and female individual organisms. Dioecious reproduction is biparental reproduction. Dioecy is one method that excludes self-fertilization and promotes allogamy (outcrossing), and thus tends to reduce the expression of recessive deleterious mutations present in a population. Flowering plants have several other methods of excluding self-fertilization, called Self-incompatibility.” https://lnkd.in/dKd4E5r View in LinkedIn

ACCUMULATED MUTATIONS. "However, in most cases, the gradual accumulation of deleterious mutations during growth is more likely to negatively influence fitness because these mutations can be potentially transmitted from shoot meristems to gametes when flowering occurs. As long as somatic mutations do not limit clonal growth, they should accumulate over the life span of genets." http://www.pnas.org/content/112/29/8859.full View in LinkedIn

HETEROSTYLY AND COMPATIBILITY. “The lengths of stamens and pistils in heterostylous flowers are adapted for pollination by different pollinators, or different body parts of the same pollinator. Thus, pollen originating in a long stamen will reach primarily long rather than short pistils, and vice versa. When pollen is transferred between two flowers of the same morph, no fertilization will take place, because of the self-incompatibility mechanism.” https://en.m.wikipedia.org/wiki/Heterostyly View in LinkedIn

BENEFICIAL MOSAICS. "The great size and longevity of many trees and clonal plants is predicted to be associated with the accumulation of numerous somatic mutations in cell lineages. Some have argued for the adaptive benefits of this type of variation because of the formation of genetic mosaics and their role in plant defense." http://www.pnas.org/content/112/29/8859.full View in LinkedIn

SO ENDS this first weekend contemplation of plant hybrids. Historical reversals of plant species assignments have not been rare, and the case study of the rampantly hybrid species rhododendron through an exhaustive study of traits illustrate how slippery the assignments can be. This is further confounded by transgressive segregation which is the formation of extreme phenotypes when compared to the parental lines, making the hybrid resemble a new species. https://lnkd.in/ddar4m9 View in LinkedIn

Free school fruit contains multiple pesticides, report shows. Little and often. https://www.theguardian.com/environment/2017/sep/05/free-school-fruit-contains-multiple-pesticides-report-shows?CMP=Share_iOSApp_Other View in LinkedIn

BLURRED SPECIES LINES. "It is nowadays evident that hybridization is widespread in certain groups of organisms, and the boundaries between varieties and species can be blurred in complexes of closely related species." https://lnkd.in/dK-A3iM View in LinkedIn