The earliest invader tolerated higher temperatures than the

Nabokov was right all along Why Evolution Is True

Nabokov was right all alongThis is a really cool result: a paper published 66 years ago, Canada Goose Outlet speculating about the evolutionary history canada goose store of a group of butterflies, has just been vindicated by a combination of new molecular and ecological work. He also taught literature at Cornell from 1948 to 1959; his classroom lectures have canada goose clearance been published and canada goose factory sale they are absolutely superb.But what you probably didn know was that he Canada Goose sale was also a world class lepidopterist, specializing in the taxonomy (description and publication of new species) of butterflies. If you read his novels, you often find a mention of butterflies.Here Nabokov at the MCZ in 1945, from the article on his butterfly work buy canada goose jacket at the New York Public Library Site:Nabokov speciality was the butterfly subfamily Polyommatinae (called because of their color) canada goose coats on sale in the family Lycaenidae.Lycaeides melissa, subspecies samuelis. The species was first described by cheap canada goose uk Nabokov.In 1945 Nabokov published a formal description and revision of some lycaenid butterfies in Psyche, the journal Canada Goose online of the Cambridge Entomological Club cheap Canada Goose (I a member!). Here the title of his paper:The paper is long (62 pages), and largely devoted to describing species based on their genitalia, the character that seems to evolve most rapidly among insects and many other groups, probably because of sexual selection (see William Eberhard excellent Sexual Selection and Animal Genitalia). At canada goose the end Canada Goose Online of the paper he speculates, based on the morphology of the various species, that the arrived in the New World from Asia over the Bering Strait. He further speculated that there were actually five successive invasions from Asia, each giving rise to a different New World group. And the first invasion produced species that made it to Central and South America, with the North American representatives eventually becoming extinct.A group of investigators from a canada goose black friday sale bunch of places, led by my friend Naomi Pierce at Harvard, just tested Nabokov theory with the modern tools of molecular biology and systematics. Their results, published in a paper in the Proceedings of the Canada Goose Coats On Sale Royal Society (free access!) and described by Carl Zimmer in yesterday New York Times, show that Nabokov was right on all counts.Using six genes, canada goose uk black friday they made a molecular phylogeny of canadian goose jacket 73 species of blues from all five described by Nabokov. The butterflies also descended, as Nabokov posited, from Asian ancestors, and certainly came to the New World by migration over the Bering Strait.The oldest group was, as Nabokov suggested, the Canada Goose Parka butterflies in the neotropics: Central and uk canada goose South America. The other groups were younger, and in the precise age sequence that Nabokov posited had arrived from Asia (and then radiated in North America).The branches of the phylogeny were dated using a clock. They were found to have begun about 11 million years ago, and continued until about 1 million years ago. During the earliest part of that period the Bering Strait was not continuous between canada goose clearance sale Asia and North America, and so some of the ancestral blues must have crossed an expanse of ocean. From that, they reconstructed the canada goose uk shop temperature tolerance of each group ancestors. (You can do this for any measurable trait, morphological or physiological, using a method called character state reconstruction And they found that the temperatures tolerated by each successive invader declined over time. The earliest invader tolerated higher temperatures than the next, and so on for all five invasions.The spiffy result: the temperature tolerances posited for each ancestor matched very nicely the temperatures thought to have prevailed in (the region on either side of the Bering Strait) at the time of the invasions. Clearly, the butterflies now in the neotropics tolerated high but not low temperatures, and so were likely driven to the south as the climate became colder. canada goose coats This also implies that each group has pretty much retained the ancestral temperature tolerance of its canada goose uk canada goose outlet outlet ancestor, though the ancestral five groups did diverge from one another in tolerance.R. Vila, C. D. Bell, R. Macniven, B. Goldman Huertas, R. H. Ree, C. R. Marshall, Z. Blint, K. Johnson, D. Benyamini, and N. E. Pierce. 2011. Phylogeny and palaeoecology of Polyommatus buy canada goose jacket cheap blue butterflies show Beringia was a climate regulated gateway uk canada goose outlet to the New World. Proc. R. Soc. He wrote somewhere in Speak, Memory missing the wonderful cadences and rhythms of the Russian language.On his western collecting trips, Nabokov sometimes stopped by the entomology museum at UC Berkeley to donate butterfly specimens Canada Goose Jackets the condition that any new species be named after him. (This according to my friend, Constantine Slobodchikoff, who did his PhD there.) (Presumably the donations were not lyceanids; otherwise he would probably have done the naming deed himself.).

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