BISTON BETULARIA

[Doug Yanega]

Glenn wrote:

>Scenes of European robins, in flight, actually selecting dark(mutant) forms
>of Biston betularia while ignoring the nearby light(normal) forms, on
>non-polluted tree trunks can be seen in the Encyclopedia Brittanica
>Educational Corporation's 1960 (or 1961) film, NATURAL SELECTION.
>Kettlewell's experiments were documented on film, although the experimental
>set-up (constructing vegetation "blinds" for photographers and their
>cameras) was, indeed, rather artificial.
>
>Still, according to what is actually shown in the film, the light form of
>the moth was certainly preferred by the birds when the moths landed on
>polluted (soot-laden) trees in the forest under study.

I think the point the creationists were challenging was whether the moths
were spontaneously landing on the tree trunks, or being placed there for
experimental purposes. They suggested it was the latter, thus essentially
accusing Kettlewell of intellectual fraud in calling the phenomenon
"natural selection". Is it evident from the film whether the moths were
being placed there for the birds to find?


Doug Yanega       Dept. of Entomology         Entomology Research Museum
Univ. of California - Riverside, Riverside, CA 92521
phone: (909) 787-4315 (standard disclaimer: opinions are mine, not UCR's)
                http://insects.ucr.edu/staff/yanega.html
  "There are some enterprises in which a careful disorderliness
        is the true method" - Herman Melville, Moby Dick, Chap. 82