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Evolution in action – Tasmanian devils are growing more resistant to a fatal disease

Scientists usually are researching evolution by studying animals that are long extinct. However, in some cases evolution can be visible in real life. For example, a new research from the international team of scientists showed that Tasmanian devils are evolving to be more resistant to Devil Facial Tumour Disease.

Tasmanian devils are iconic marsupials, but their population got dramatically decreased by the Devil Facial Tumour Disease. Image credit: KeresH via Wikimedia, CC BY-SA 3.0

Tasmanian devils are iconic marsupials, but their population got dramatically decreased by the Devil Facial Tumour Disease. Image credit: KeresH via Wikimedia, CC BY-SA 3.0

This extremely dangerous fatal transmittable cancer was first discovered back in 1996 was spreading so fast that evolution took an immediate action. Scientists say that this animal species may be able to survive because of sudden changes two regions in the genomes of the iconic marsupials. These evolutionary changes are coming right on time, because Devil Facial Tumour Disease already reduced the population of Tasmanian devils by 80%.

Scientists set out to see how Tasmanian devils deal with the spread of this fatal disease. They established long-term research sites and started creating a tissue archive back in 1999. After 17 years of work this archive became an increasingly valuable resource to study Tasmanian devils and the disease attacking them. Such database allows scientists to see how different genomes are, comparing animals from when the disease emerged and now. International team of scientists took on this challenge to see how Tasmanian devils are adapting.

Researchers compared the frequency of genes in specific regions of DNA. Menna Jones, a member of the research team from the University of Tasmania, said: “We identified two small genomic regions in the DNA samples from all three of the recent collection sites that exhibited significant changes in response to the strong selection imposed by the disease”. Five out of seven genes in the DNA region are related to cancer or immune function in other mammals, which means that Tasmanian devils are evolving to be more resistant to Devil Facial Tumour Disease.

Now scientists will try to identify the actual functions of these genetic regions they discovered. They hope that healthy resistant Tasmanian devils will lead the survival of the species or will be used to reintroduce the animals to the ecosystem if such need arises.

Source: utas.edu.au