I ground out a page of turgidity earlier this evening, and found that Nature had an entire review on the subject. Or on something very close to it, which is the question of whether hybridisation followed by allopolyploidy (doubling the dissimilar sets of chromosomes) leads to speciation. It does. I was startled by James Mallet, the author's, estimate that up to 75% of breeding attempts in some animals were inter-specific. I must live a sheltered life. Around a quarter of all plants routinely breed with other species. If the result doubles its chromosomes and survives the act, it becomes a species: Primula kewensis, for example, which did this feat unassisted on the bench in 1909.
The 15 March issue is very interesting, as it is dedicated to Linnaeus' memory, and reviews the state of taxonomy. Words are said about orchids: over-split, it is thought, "taxonomic exaggeration", it is said. Darwin criticised species-mongers, who thought that the question of priority was "the greatest curse to natural history." The P. kovachii controversy of 2002 is cited as an example of how alleged knavery is irreversibly awarded with recognition into posterity. I know that this is controversial. I will quote the section verbatim: don't hit me, hit the author. "Orchids have long attracted a plethora of amateurs. In 2002, for instance, Michael Kovach smuggled a ladyslipper orchids from Peru and asked that the taxonomist at the Marie Selby Botanical Gardens in Sarasota, Florida, name it after him. Selby's experts reportedly knew that Eric Christenson, an unaffiliated taxonomist also in Florida, has his own description of the species scheduled for a forthcoming issue of Orchids. Selby rushed a two-page description of Phragmepedium kovachii to print as a supplement to its house journal. Kovach eventually pleaded guilty to illegal possession and trade of an endangered species. Selby was fined for its role in the scandal. None of this matters in the eye of the taxonomic code, which will honour Kovach for ever. " Also in the review, how monocot-dicot dichotomy doesn't work, how the family tree of the flowering plants is being pruned, and under the heading "the species and the specious" whether we should go with phylogenic classification system - the alleged back seat driver of species inflation - or return to the older biological species concept. Phylogenics is estimated to generate half as many species again as the biological concept approach. (Phylogenics relies upon observables: if a group of organisms have an observable by which they differ from another - three hairs instead of two on the labellum - then they counts as separate species. The biological approach relied more upon observer common sense: did it act like a species? Not of course the easiest thing to assert when looking at a squashed specimen half a planet away from its origins.) But enough. ______________________________ Oliver Sparrow +44 (0)20 7736 9716 www.chforum.org _______________________________________________ the OrchidGuide Digest (OGD) orchids@orchidguide.com http://orchidguide.com/mailman/listinfo/orchids_orchidguide.com
