The Cothillers and Callimorpha dominula..
Jul 27, 2017 13:08:56 GMT
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Post by nomad on Jul 27, 2017 13:08:56 GMT
Cothill Fen in Oxfordshire (historically part of Berkshire), home to a number of rare insects and plants, is world famous because this is where the father of ecological genetics, Edmund Brisco "Henry" Ford (1901–1988) carried out his studies on the Scarlet Tiger moth, Callimorpha dominula. From 1941 onward, Ford and his assistants counted Scarlet Tiger moths for two weeks every July in the marshes at Cothill. Among this isolated population of C. dominula, there were two rare phenotypes. Ford was very keen to prove that these phenotypes, were as a direct result of "natural selection" and not as some American scientists purported, from a process known as "Random drift".
At Cothill Fen, Ford found that an aberration known as ab. bimacula Cockayne 1928, formed a very low percentage of the population of C. dominula. A higher percentage of the specimens of C. dominula at Cothill, were Ford recorded, those of ab. medionigra Cockayne 1928. According to Ford, because ab. medionigra represented a higher percentage of the population of C. dominula, it was a polymorphic form, being to numerous to be an aberration. Cothill Fen was the headquarters of both ab. bimacula and ab. medionigra in Britain.
I have always had my reservations in regarding ab. medionigra as a polymorphic form. Ford stated in his book, Moths in the New Naturalist series (1955) that medionigra has a smaller or absent white central forewing spot and the hindwing has an extra central black spot but admits that it is highly variable. Ford figures three specimens of medionigra on plate 11 of his book. Only one of the three specimens figured by Ford has the extra hindwing black spot but another has a joined black band, while in the other pictured specimen it is absent. ab. medionigra does not show what I believe are the stable characteristics of a good polymorphic form, being too variable and in my opinion represent variation within the type at Cothill that are intermediate to ab. bimacula.
A rather strange and true fact about Henry Ford, is that he destroyed all of his specimens relating to his genetic experiments and field studies with C. dominula, Biston betularia and Maniola jurtina. Ford also burned all his notes regarding his studies with these species. This is a very strange act for a scientist to destroy his study specimens and note books that should have been preserved, so others could study his findings.
Ford was always the eccentric. Once the C. dominula two week counting season was over in the fen, he took all his students and assistants, he dubbed the Cothillers, on a tour of the Oxford pubs. Before a beer you had to down a gin, after visiting numerous pubs, his Cothillers were reeling, but Ford remained apparently sober, and was able to quip to a woman who was collecting for the 'Protection of Children', "here is a five pound note, I am sooo glad someone is doing something to prevent children".
Below. The famous Cothill Fen, photographed July 2017.
Below. C. dominula ab. bimacula Cockayne 1928. Almost certainly from Cothill Fen, 1938. Ex coll L.W. Newman.
Below. C. dominula labelled ab. medionigra probably from Cothill 1940. Ford's pictured specimens in Moths (plate 11) have inner forewing spots, which are absent in this specimen. Ex Coll C. Rippon.
At Cothill Fen, Ford found that an aberration known as ab. bimacula Cockayne 1928, formed a very low percentage of the population of C. dominula. A higher percentage of the specimens of C. dominula at Cothill, were Ford recorded, those of ab. medionigra Cockayne 1928. According to Ford, because ab. medionigra represented a higher percentage of the population of C. dominula, it was a polymorphic form, being to numerous to be an aberration. Cothill Fen was the headquarters of both ab. bimacula and ab. medionigra in Britain.
I have always had my reservations in regarding ab. medionigra as a polymorphic form. Ford stated in his book, Moths in the New Naturalist series (1955) that medionigra has a smaller or absent white central forewing spot and the hindwing has an extra central black spot but admits that it is highly variable. Ford figures three specimens of medionigra on plate 11 of his book. Only one of the three specimens figured by Ford has the extra hindwing black spot but another has a joined black band, while in the other pictured specimen it is absent. ab. medionigra does not show what I believe are the stable characteristics of a good polymorphic form, being too variable and in my opinion represent variation within the type at Cothill that are intermediate to ab. bimacula.
A rather strange and true fact about Henry Ford, is that he destroyed all of his specimens relating to his genetic experiments and field studies with C. dominula, Biston betularia and Maniola jurtina. Ford also burned all his notes regarding his studies with these species. This is a very strange act for a scientist to destroy his study specimens and note books that should have been preserved, so others could study his findings.
Ford was always the eccentric. Once the C. dominula two week counting season was over in the fen, he took all his students and assistants, he dubbed the Cothillers, on a tour of the Oxford pubs. Before a beer you had to down a gin, after visiting numerous pubs, his Cothillers were reeling, but Ford remained apparently sober, and was able to quip to a woman who was collecting for the 'Protection of Children', "here is a five pound note, I am sooo glad someone is doing something to prevent children".
Below. The famous Cothill Fen, photographed July 2017.
Below. C. dominula ab. bimacula Cockayne 1928. Almost certainly from Cothill Fen, 1938. Ex coll L.W. Newman.
Below. C. dominula labelled ab. medionigra probably from Cothill 1940. Ford's pictured specimens in Moths (plate 11) have inner forewing spots, which are absent in this specimen. Ex Coll C. Rippon.
