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Computer theory cracks rainforest gene secrets
November 14, 2008
Minyon quandong fruit and leaves
Minyon quandong fruit on the ground
November 14, 2008
Minyon quandong fruit and leaves
Minyon quandong fruit on the ground
An innovative approach to studying genetics has provided new information about how Australia's dwindling remnants of rainforest will cope as the planet grows warmer due to climate change.
According to research undertaken at the UNSW Ecology and Evolution Research Centre in conjunction with the National Herbarium of NSW, indications might be found in the genes of the rainforest plant species that have endured. The new study raises hope these species may be better equipped to handle the change than previously thought - and that some might even expand their ranges under favourable conditions.
Australia once boasted vast tracts of rich rainforests but, after millions of years of gradual drying, the continent has only a few pockets surviving.
These rainforests contain ancient lineages of plants, many unique to Australia, and a surprisingly high degree of biodiversity, according to the lead authors of the study, Dr Bill Sherwin and Dr Maurizio Rossetto. Their report was published recently in the American Journal of Botany.
Those genetic tr
Researchers at the UNSW Ecology and Evolution Research Centre employ information theory to delve into the biology of a diverse array of species, from birds to snails to flies to trees. Because genes are information, decades of knowledge about the flow of computer information can be applied directly to genes. This has greatly improved assessment of dispersal between populations, a vital tool for conservation management and all population biology.
They teamed with the National Herbarium of NSW in the first major application of information theory to the genetics of a wild species: the Minyon quandong, a rare native fruit tree thought to be extinct until its discovery in 1992.
The Minyon quandong is found only at five sites in warm temperate rainforests in the Mt Warning area of north-eastern NSW. It has a close relative in Papua New Guinea, suggesting that its lineage might once have been far more widespread: if so, the few remnants might be inbred and in long-term decline.
However, the study revealed genetic information showing the signature of long-term stable isolates; that is, the species did not evolve very recently, nor has it been through an evolutionary bottleneck.
That finding suggests that even though the Minyon quandong grows in highly restricted areas and in relatively small numbers, it is probably not in decline and still has considerable capacity to evolve and even expand its range to suitable unoccupied habitat that exists nearby.
So why hasn't this tree spread? Ge
Nevertheless, the study has shown that even small populations of highly localised species can persist for very long periods within Australia's rainforests, which the fossil record shows have acted time and again as a refuge where many species can retreat during severe climate cycles and re-emerge in kinder times.
"A lesson from this and other studies is that rainforests can be quite resilient," says Dr Sherwin "But we're also increasingly coming to appreciate that they are not just species living together but depending upon each other, so they need to be conserved as a whole to keep options open for the future."
The members of the study team were: Maurizio Rossetto, Robert Kooyman and Rebecca Jones from the National Herbarium of NSW, and Bill Sherwin from the Ecology and Evolution Research Centre of the University of NSW School of Biological, Earth and Environmental Sciences. The study was funded by the Australian Research Council and the NSW Department of Environment and Climate Change.
Media contacts:
Dr Bill Sherwin: w.sherwin@unsw.
Bob Beale, UNSW Faculty of Science media liaison: bbeale@unsw.edu
