From aloes to zebras (and five new species using vital differences not perceivable by humans)

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dc.contributor.author Van der Bank, Herman
dc.date.accessioned 2008-11-03T07:17:46Z
dc.date.available 2008-11-03T07:17:46Z
dc.date.issued 2008-11-03T07:17:46Z
dc.identifier.uri http://hdl.handle.net/10210/1451
dc.description Inaugural lecture--Dept. of Zoology, University Johannesburg, 21 July 2005 en
dc.description.abstract South Africa is a signatory of the convention on biological diversity, in which three levels (genetic, species and ecological) are addressed. My field of research is mainly on the first level mentioned. Genetic data is useful since inferences about the past (e.g. time of divergence and population history), present (diversity, population size, reproductive mixing, hybridisation, inbreeding) and future (selection, conservation, management) can be made. In addition, the technique I use can be applied to plants and animals. Results of studies that range from aloes to zebras are discussed and also how five new species were discovered. This is how Rachel Ashton (section editor, BBC Wildlife Magazine, Broadcasting House, U.K.) described one of our new electric fish: Species are traditionally defined by something we can perceive - be it size, shape, colour or song. But for Pollimyrus marianne, a snout fish from the Okavango-Upper Zambezi River System, the vital difference is something humans can't perceive at all - the discharge pattern from its electric organ. P. marianne of the Zambezi River is virtually indistinguishable from another species, P. castelnaui of the Okavango River, both in looks and in habitat preference. But Herman van der Bank found significant genetic differences and Bernd Kramer discovered that the electric signals are very different, especially those used for mate choice. Comparisons of mitochondrial DNA also confirmed the new Zambezi species. Only individuals from one smaller river (the Kwando), which is running between and mostly in parallel to the two main rivers, have a specific, third electric pattern. Except for occasional very high flooding, this river has been isolated from the Zambezi for at least 60 years, too small a time for definable mitochondrial DNA differences to accumulate by random mutation. But in spite of the sporadic floodings P. marianne was capable of conserving its distinct species-specific signal to identify it in its new electric fish community. The species mentioned above was named after professor Kramer’s late mother (Marianne) and another new species was named after my late father-in-law (Pierre Wessels). These names (and people) are now fixed in history and will be remembered for eternity. en
dc.language.iso en en
dc.rights University of Johannesburg en
dc.subject Genetic biological diversity en
dc.subject Biodiversity en
dc.subject Plants - Genetic data en
dc.subject Animals - Genetic data en
dc.subject Pollimyrus marianne en
dc.subject Pollimyrus castelnau en
dc.title From aloes to zebras (and five new species using vital differences not perceivable by humans) en
dc.type Inaugural en

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