Month: September 2022

NEW VISTAS. “A major conceptual issue concerns the gap between the “pathogen focused” culture of a vast majority of pathologists, and the ecological concepts necessary to tackle microorganism communities as a whole.” https://lnkd.in/gEfVGaC View in LinkedIn

SO ENDS our venture into new thinking on the concept of a pathogen, concurrent with new thinking on how many systems interact and collaborate in balance and out of balance. We are in a new age that forces us to consider context and co-evolution more seriously than before, and this is particularly important in the thinking about health and disease. View in LinkedIn

ALTERNATION OF GENERATIONS. "Land plants have alternation of generations, for which the sporophyte generation produces spores rather than gametes. Strictly speaking, the sporophytes of land plants do not have either male or female reproductive organs. The gametophytes of flowering plants are of a single sex; the male gametophytes are contained within the pollen, and the female gametophytes are contained within ovules." https://lnkd.in/gJcDDvC View in LinkedIn

DIPLOID-HAPLOID CYCLE. "The sporophyte generation is called dioecious when each sporophyte has only one kind of spore-producing organ whose spores ultimately give rise to either all male gametes (sperm) or all female gametes (eggs)." https://lnkd.in/gJcDDvC View in LinkedIn

SEXUAL DIFFERENTIATION. "Darwin (1871) described many striking examples in which females and males of animal species differ dramatically in morphology, coloration, size, and behavior." https://lnkd.in/ge7JD6J View in LinkedIn

ROAD TO EXTINCTION. "Dioecy (i.e. having separate sexes) is a rather rare breeding system in flowering plants. Such rareness may result from a high probability of extinction in dioecious species because of less efficient dispersal and the costs of sexual selection, which are expected to harm dioecious species’ survival on the long term." https://lnkd.in/gRVz_Qd View in LinkedIn

"THESE HANDICAPS should decrease the effective population size of dioecious species, which in turn should reduce the efficacy of selection. Moreover, sexual selection in dioecious species is expected to specifically affect some genes, which will evolve under positive selection." https://lnkd.in/gRVz_Qd View in LinkedIn

DEAD END. "Our results are consistent with the view that dioecy is an evolutionary dead end in flowering plants." http://onlinelibrary.wiley.com/doi/10.1111/jeb.12052/pdf View in LinkedIn

LESS DIVERSIFICATION. "In angiosperms, dioecious clades tend to have fewer species than their nondioecious sister clades. This departure from the expected equal species richness in the standard sister clade test has been interpreted as implying that dioecious clades diversify less and has initiated a series of studies suggesting that dioecy might be an 'evolutionary dead end'." https://lnkd.in/gGPGHvb View in LinkedIn

IMPORTANT FOOTNOTE. "Dioecy is associated with higher diversification rates in flowering plants. However, it is crucial for this new test to distinguish between ancestral and derived cases of dioecy, a criterion that was not taken into account in the available data set." https://lnkd.in/gGPGHvb View in LinkedIn