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MISTAKEN SPECIES. "Hybridization has become a focal topic in evolutionary biology, and many taxonomists are aware that the process occurs more frequently than previously assumed. Nonetheless many species and varieties are still described without explicitly considering the possibility of hybridization, especially in countries that have relatively short scientific histories, but which often possess the highest species diversities." https://lnkd.in/dK-A3iM View in LinkedIn

THREE DISADVANTAGES. "Despite the many advantages of vegetative reproduction, there is a growing recognition that clonal growth can also affect sexual reproduction in ways that may be detrimental to fitness. Three particular influences have been identified." http://www.pnas.org/content/112/29/8859.full View in LinkedIn

WIDESPREAD PLANT HYBRIDIZATION. "The occurrence of hybrids, here meaning offspring resulting from two genetically distinct groups of organisms, has been known to taxonomists for a long time. 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." https://lnkd.in/dK-A3iM View in LinkedIn

ADAPTIVE OPTION. "Clonal populations often persist in habitats in which sexual reproduction is prevented, either because of the absence of mating partners, or where ecological conditions are unfavorable for seed set, seed germination, or seedling establishment." http://www.pnas.org/content/112/29/8859.full View in LinkedIn

SONG OF DARWIN. "The more I study nature, the more I become impressed […] that the contrivances and beautiful adaptations [acquired through natural selection] transcend in an incomparable degree [those] which the most fertile imagination of the most imaginative man could suggest with unlimited time at his disposal." https://lnkd.in/eykUy37 View in LinkedIn

FRAGMENT FROM NATURE for this and next weekend focuses on the vexing issue of hybrids, starting with a case study of hybrid rhododendrons, and then to animal hybrids. The transition into a species for a population, which is generally unable to breed with organisms outside that species, is a central tenet of evolutionary theory. But the case study shows that this assignment can be more difficult than it seems. View in LinkedIn

HETEROSTYLY AND SELF. “The morph phenotype is genetically linked to genes responsible for a unique system of self-incompatibility, termed heteromorphic self-incompatibility, that is, the pollen from a flower on one morph cannot fertilize another flower of the same morph.” https://en.m.wikipedia.org/wiki/Heterostyly View in LinkedIn

“HERKOGAMY is a common strategy employed by hermaphroditic angiosperms to reduce sexual interference between male (anthers) and female (stigma) function. Herkogamy differs from other such strategies (e.g. dichogamy) by supplying a spatial separation of the anthers and stigma.” https://lnkd.in/dAT6_q2 View in LinkedIn

HETEROSTYLY DEFINED. “Heterostyly is a unique form of polymorphism and herkogamy in flowers. In a heterostylous species, two or three morphological types of flowers, termed "morphs", exist in the population. On each individual plant, all flowers share the same morph. The flower morphs differ in the lengths of the pistil and stamens, and these traits are not continuous.” https://lnkd.in/dBgeGam View in LinkedIn

POLYMORPHISM #3. "Heterostyly and dioecy are the best-known sexual polymorphism of this type, with heterostylous populations usually composed of two (distyly) or three (tristyly) style morphs, and dioecious populations composed of female and male plants." http://www.pnas.org/content/112/29/8859.full View in LinkedIn