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TRANSGRESSIVE CHARACTERISTICS. “Studies of quantitative traits in segregating hybrid populations sometimes report the presence of phenotypes that are extreme relative to those of either parental line. The generation of these extreme phenotypes is referred to as transgressive segregation, and this is a major mechanism by which extreme or novel adaptations observed in new hybrid ecotypes or species are thought to arise.” https://lnkd.in/d4xXNs5 View in LinkedIn

SPECIES NAMING REVERSALS. "Over time there have been many examples across different genera and families, where a plant described as a new species has been subsequently proven to be a hybrid." https://lnkd.in/dK-A3iM View in LinkedIn

TRANSGRESSIVE PROBLEM. "A further problem can arise from transgressive characters, meaning traits that are not seen in either parent. Transgressive characters can already occur at a lower frequency in F1 hybrids, but are frequently reported in later generation hybrids." https://lnkd.in/dK-A3iM View in LinkedIn

REPRODUCTIVE ISOLATION IS KEY. "Regarding description of hybrids as species, an important distinction should be made between reproductively isolated taxa that originated through hybrid speciation (hybrid species) and continuously re-formed hybrids that have distinct features but do not represent a reproductively isolated lineage." https://lnkd.in/dK-A3iM View in LinkedIn

REASSIGNED RHODODENDRON SPECIES. "Together, the two species investigated here have nine described infraspecific taxa: five for R. delavayi, and four for R. irroratum, however, these are all assigned the rank of subspecies." https://lnkd.in/dK-A3iM View in LinkedIn

MISNAMED PLANT SPECIES. "Despite ongoing debate about the overall evolutionary importance of hybridization, the process has been shown to be widespread and relatively common in plants, occurring across many different families and floras. Indeed, Rieseberg (1997) suggested that a worldwide average of 11 % of all described plant species may be hybrids, and that this figure may even be an underestimate." https://lnkd.in/dK-A3iM View in LinkedIn

SEX RATIOS. Populations usually strive to generate equal numbers of each sex, but extreme deviations from this condition do occur quite frequently. Read this fascinating article about these deviations from the assumed norm. https://lnkd.in/e2CjiWF View in LinkedIn

IMPACT. "The widespread occurrence in dioecious species of both sexual and clonal reproduction provides an opportunity to investigate how these two reproductive modes interact to influence sex ratios and fitness in plant populations." http://www.pnas.org/content/112/29/8859.full View in LinkedIn

LABILE AND UNCONSTRAINED. "The occurrence of different mechanisms of clonal reproduction among related species suggests that clonal strategies are relatively labile and that their evolution is not strongly constrained." http://www.pnas.org/content/112/29/8859.full View in LinkedIn

FREQUENCY. “There are 15 600 dioecious angiosperms in 987 genera and 175 families, or 5–6% of the total species (7% of genera, 43% of families), with somewhere between 871 to 5000 independent origins of dioecy. Some 43% of all dioecious angiosperms are in just 34 entirely dioecious clades, arguing against a consistent negative influence of dioecy on diversification.” https://lnkd.in/dUmPa47 View in LinkedIn