Touatara: The fastest evolving animal
In a study of the "living dinosaur" of New Zealand, touatara, the evolutionary biologist and expert in ancient DNA, Professor David Lambert and his team from the Alan Wilson Centre of Molecular Ecology and Evolution, discovered DNA sequences from the bones of ancient touatara back to 8.000 years. They found that although touatara have remained physically same level for very long periods of evolution at the molecular level are evolving faster than any other animal has been examined so far. The survey will be published in the March issue of the journal Trends in Genetics. "What we found is that touatara has the highest molecular evolutionary rate has been measured until now." Says Professor Lambert.
The percentage change for Adelie penguins which the Lambert and his team studied for several years in Antarctica, is slightly lower than the Touatara. The percentage of Touatara is significantly faster than for animals like the bear cave, the lion, the horse.
"Of course we expected that touatara doing everything late - they grow slowly, reproduce slowly and have a very slow metabolism, would have evolved slowly. In fact, at DNA, evolving incredibly rapidly, which supports the hypothesis previously proposed by the evolutionary biologist Allan Wilson, who said that the rate of molecular evolution was not related to the rate of morphological evolution.
Alan Wilson is a veteran of molecular evolution. His ideas were controversial when it introduced forty years ago, but new research supports them. Professor Lambert says the findings could be useful in future surveys and plans for managing touatara, and the team now hopes to expand its work in the evolution of other animal species.
"We want to go and measure the rate of molecular evolution for humans, and to work more with the MET and Antarctic fish to see if rates of DNA change are independently in these species. There are human mummies in the Andes and some very good samples in Siberia where we have partners, so we hope that we can measure the rate of human evolution in these cases. The toatar, Sphendon punctatus, found only in New Zealand and is the sole survivor of a class of reptiles, Sphenodontia who lived with the dinosaurs, and initially got from other reptiles 200 million years ago during the Upper Jurassic.
source: Cell Press
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