The Tasmanian Devils ,Sarcophilus harrisii ,are suffering from a form a cancer called the devil facial tumour disease (DFTD) which first surfaced in the mid 1990s. DFTD is a 100% fatal infectious disease that can be transferable by physical contact, namely, biting. According to BBC News, DFTD has caused the population to decrease drastically, up to 60% in the past decade. Scientist believe that they found ‘very specific Schwann genes that are expressed in the cancer, we can use these genes as diagnostic markers.’
As DFTD tumor displays itself on the face of the Tasmanian Devils, it is easily recognizable if is suffering from the disease. What has intrigued me is that why has the Tasmanian Devil not ‘learnt’ to avoid those who are infected? DFTD has been around for roughly 10 years now, is too narrow a time frame for the learning process to take place? It seems like if the species need a longer time period to either learn to avoid or develop a diverse set of genes that proves to be immune to DFTD.
In the eyes of conversation biology, the adversity that the Tasmanian Devils are currently facing brings about the emphasis on the possible negative consequence of the lack of genetic diversity within a population. It brings to the forefront the issue of the captive population and the importance on genetic diversity. ‘The long-term consequence of loss of genetic diversity is lack of evolutionary potential to respond to novel challenges such as environmental change.’
The prevention/cure for DFTD currently still escapes science. The only possible and most effective solution points to the isolation of uninfected animals from the infected animals.
References:
Video – ‘ Tasmanian devils under threat – 04 Oct 07 ‘ by AljazeeraEnglish Youtube channel, 04 October 200 URL: http://www.youtube.com/watch?v=57jFF-pk_GA (accessed 06 April 2010)
‘Tasmanian devil facial cancer origins ‘identified’ ‘ by Mark Kinver. BBC News, 1 January 2010. URL: http://news.bbc.co.uk/2/hi/8433645.stm (accessed 7 April 2010)
‘Tasmanian devil spreads cancer by biting, study says’ by Richard A. Lovett. National Geographic News, 27 February 2006 . URL: http://news.nationalgeographic.com/news/2006/02/0227_060227_tasmanian.html
Second source:
McCallum, Harmish, 2008. Tasmanian Devil facial tumor disease: lessons for conservation biology.Trends in Ecology and Evolution , 23 (11): 631-637