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Description
This programme examines three pairs of species of picture wings and attemots to answer the question of why so many species of drosophila have evolved in Hawaii.
Metadata describing this Open University video programme
Module code and title: S364, Evolution
Item code: S364; 10
First transmission date: 20-08-1981
Published: 1981
Rights Statement:
Restrictions on use:
Duration: 00:24:00
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Producer: Roger Jones
Contributors: Hampton Carson; Val Giddings; Ken Kaneshiro; Irene Ridge
Publisher: BBC Open University
Keyword(s): Drosophila; Evolution; Fruitflies; Hawaii; Picture wing fruitflies; Speciation
Footage description: Over shots of the Pacific Ocean and shots of drosophila, commentary introduces the programme. Shots of several of the Hawaiian islands with coastal and interior scenes. Commentary describes the various habitats found there. Shots of Irene Ridge in the rain forest on the north-west slopes of Haleakala. She describes the habitat in this particular area and points out that it is a good location for collecting and studying drosophila. Ridge looks at a particular species of picture wing fruitfly, drosophila clavisetae, which feeds and breeds only on the woody lobelioid clermontia on the island of Maui. Shots of the fly, its larvae and of two adults mating. Ridge goes on the look at another species of picture wing, drosophila planitibia which lives in the same habitat as clavisetae. Shots of larvae and adult planitibia. Shots of two adult males fighting over breeding territory. Shots of some other species of drosophila found in Hawaii. Ken Kaneshiro, in the medium wet forests of one of the younger Hawaiian islands, describes the habitat. He examines a shrub of the clermontia genus on which feed and breed two closely related picture wings which probably shared a common ancestor from the Maui Complex. Shots of researchers in the forest looking for a site for the capture and study of particular species of picture wings. Commentary points out the difficulties of finding suitable sites. Shots of the researchers placing bait and catching flies. Shots of drosophila silvestris, including close ups of both male and female. Shots of a closely related species, drosophila heteroneura. Again, close ups of both male and females are shown. The programme goes on to look at two other closely related species, diosophila silvarentis and heedi. Both species feed on the rotting bark of myoporum leaves. Shots of the tree and close ups of bark and sap. Shots of silvarentis larvae feeding on the sap of the tree. Ken Kaneshiro (voice over shots of the forest habitat) explains briefly how the breeding place of the other species, drosophila heedi, was discovered. Shots of Silvarentis and heedi larvae. Ridge (voice over) explains that behaviour probably played a large part in the adaptation of these two species to their breeding habitat. Irene Ridge and Hampton Carson look at the reasons why so many species of drosophila evolved. They point out that habitat isolation played a part but that behaviour adaptation played a larger part. Shots of forest and of picture wings as they talk. Ridge goes on to examine the sexual behaviour of the two closely related species, drosophila planitibia and clavisetae. Shots of adults of both species of male planitibia fighting and of planitibia and clavisetae courtship. Over shots of drosophilia silvestris and heteroneura during courtship and mating, Ridge discusses the sexual behaviour of these two species. Irene Ridge and Hampton Carson explain that the inherited sexual behaviour of the picture wings is the most important factor in the evolution of these flies. Shots of flies copulating and shots of several different species of flies.
Master spool number: HOU3600
Production number: FOUS121D
Videofinder number: 2061
Available to public: no