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SEXUAL SELECTION. "The role of sexual selection in speciation with gene flow, however, is less clear; some studies suggest it can drive the speciation process, while others suggest it can inhibit it, under different conditions." https://lnkd.in/g9StYjV View in LinkedIn

OVERLOOKED. "Darwin (1871) largely neglected the possibility that sexual selection might also operate in plants. This may have been because of their non-sentient habit, primarily hermaphroditic sexual condition, and less conspicuous sexual dimorphism in dioecious species." https://lnkd.in/ge7JD6J View in LinkedIn

GENE FLOW AND SPECIATION. "Speciation in the presence of gene flow, in sexual species, can be driven by two general processes: (i) nonrandom mating that results in assortative mating, the mating of like with like, which reduces gene flow between groups, and (ii) divergent selection, which favors extremes in a population and thus can lead to a splitting of the species." https://lnkd.in/g9StYjV View in LinkedIn

DIOECIOUS TRAITS. "Recent large-scale molecular phylogenetic analyses confirm some of the correlations between dioecy and ecological traits and highlight the diversification of dioecious lineages associated with ecological features" such as woodiness, climber habit, and fleshy fruits. https://lnkd.in/g_fheyF View in LinkedIn

GENE FLOW PROMOTES COHESION. "One of the most intriguing aspects of speciation is how it might proceed under the most difficult of circumstances, namely in the face of gene flow. Gene flow poses an especially interesting problem for evolutionary theorists because it counters the forces driving differentiation between species, leading to continued cohesion across them." https://lnkd.in/g9StYjV View in LinkedIn

CHARACTERISTICS. "Dioecy has been correlated with plant spatial distribution, tropical floras, oceanic islands, and oligotrophic environments, and since Darwin (1877), resource allocation has been suggested as a causal factor in the evolution and maintenance of dioecy." https://lnkd.in/g_fheyF View in LinkedIn

LAG PHASE. “It took some time for people to recognize that a terrible epidemic was breaking out among them and for chroniclers to note this. The timescale varies: in the countryside it took about forty days for realisation to dawn; in most towns with a few thousand inhabitants, six to seven weeks; in the  cities with over 10,000 inhabitants, about seven weeks, and in the few metropolises with over 100,000 inhabitants, as much as eight weeks.” https://lnkd.in/gZz5b2U View in LinkedIn

SHIP RATS. “Importantly, plague was spread considerable distances by rat fleas on ships. Infected ship rats would die, but their fleas would often survive and find new rat hosts wherever they landed. Unlike human fleas, rat fleas are adapted to riding with their hosts; they readily also infest clothing of people entering affected houses and ride with them to other houses or localities. This gives plague epidemics a peculiar rhythm and pace of development and a characteristic pattern of dissemination.” https://lnkd.in/gZz5b2U View in LinkedIn

TWENTY THREE DAYS. “The infection takes three–five days to incubate in people before they fall ill, and another three–five days before, in 80 per cent of the cases, the victims die. Thus, from the introduction of plague contagion among rats in a human community it takes, on average, twenty-three days before the first person dies.” https://lnkd.in/gZz5b2U View in LinkedIn

CONTEMPORARY ACCOUNT: “in many places in Siena great pits were dug and piled deep with the multitude of dead [...] And there were also those who were so sparsely covered with earth that the dogs dragged them forth and devoured many bodies throughout the city.” https://lnkd.in/gZz5b2U View in LinkedIn