Available online
Description
This video is about the adaptive radiation of genetically very close species of plants classified into three genera, Argyroxiphium Dubautia and Wilkesia known as the Silversword Alliance. the first... part illustrates the habit and habitat of 13 of these species in detail. In the second part, three examples of hybridisation are given, together with estimates of the fertility of the F1 hybrids given by pollen staining experiments. The hybrids shown are between Dubautia arborea and ciliolata, both n=13, between Dubautia scabra and ciliolata, n=14 and n=13, and between Dubautia menziesii and Argyroxiphium sandwicense. The third part looks at evidence for the adaptive radiation of the Silversword Alliance throughout the Hawaiian archpelago. Chromosomal data and chloroplast DNA data are discussed, and an animation shows how the n=13 group evolved from an n=14 ancestral species. The final topic is the origin of the Hawaiian genome from a Californian tarweed and two theories of how the n=14 common ancestor arose are presented.
This video is about the adaptive radiation of genetically very close species of plants classified into three genera, Argyroxiphium Dubautia and Wilkesia known as the Silversword Alliance. the first... part illustrates the habit and habitat of 13 of these species in detail. In the second part, three examples of hybridisation are given, together with estimates of the fertility of the F1 hybrids given by pollen staining experiments. The hybrids shown are between Dubautia arborea and ciliolata, both n=13, between Dubautia scabra and ciliolata, n=14 and n=13, and between Dubautia menziesii and Argyroxiphium sandwicense. The third part looks at evidence for the adaptive radiation of the Silversword Alliance throughout the Hawaiian archpelago. Chromosomal data and chloroplast DNA data are discussed, and an animation shows how the n=13 group evolved from an n=14 ancestral species. The final topic is the origin of the Hawaiian genome from a Californian tarweed and two theories of how the n=14 common ancestor arose are presented.
| Module code and title: | S365, Evolution |
|---|---|
| Item code: | S365; 08; US version |
| Published: | 1990 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 01:00:00 |
| + Show more... | |
| Producer: | David Jackson |
| Contributor: | Irene Ridge |
| Publisher: | BBC Open University |
| Keyword(s): | Adaptive; Archipelago; Argyroxiphium; Chromosome; DNA; Dubautia; Evolution; Hawaiian; Radiation; Wilkesia |
| Subject terms: | Botany--Hawaii; Compositae |
| Master spool number: | HOU6798 |
| Production number: | HAP5294 |
| Videofinder number: | 4086 |
| Available to public: | no |
