The Tasmanian devil (Sarcophilus harrisii) is a species of mammal whose only wild population is native to the isolated island of Tasmania, off the coast of Australia. Tasmanian devils have a very low level of genetic diversity across the entire species. Researchers hypothesize this lack of diversity is the result of several genetic bottlenecks in the species’ history.
In 1996 a new disease called devil facial tumor disease (DFTD) appeared in the wild Tasmanian devil population. DFTD can spread from one animal to another and causes the death of most affected animals. The impact of DFTD on the Tasmanian devil population has resulted in a decrease in the total population of more than 85% over the last two decades.
(a) Describe the process that maintained a stable Tasmanian devil population size before the appearance of DFTD in 1996.
(b) Explain how the huge reduction of the Tasmanian devil population since 1996 affects the susceptibility of the current population to new diseases in comparison with the susceptibility of the population before 1996.
(c) Tasmanian devils are top predators and are considered a keystone species in their community. Predict the effect of the rapid reduction of the Tasmanian devil population on the rest of the community.
(d) Justify the prediction of part (c).
Answers
Answer:
The Tasmanian devil introduction:
Explanation:
The Tasmanian devil (Sarcophilus harrisii) is threatened with extinction because of a contagious cancer known as Devil Facial Tumor Disease. The inability to mount an immune response and to reject these tumors might be caused by a lack of genetic diversity within a dwindling population. Here we report a whole-genome analysis of two animals originating from extreme northwest and southeast Tasmania, the maximal geographic spread, together with the genome from a tumor taken from one of them. A 3.3-Gb de novo assembly of the sequence data from two complementary next-generation sequencing platforms was used to identify 1 million polymorphic genomic positions, roughly one-quarter of the number observed between two genetically distant human genomes. Analysis of 14 complete mitochondrial genomes from current and museum specimens, as well as mitochondrial and nuclear SNP markers in 175 animals, suggests that the observed low genetic diversity in today's population preceded the Devil Facial Tumor Disease disease outbreak by at least 100 y. Using a genetically characterized breeding stock based on the genome sequence will enable preservation of the extant genetic diversity in future Tasmanian devil populations.
Answer: introduction to tasmanian
Explanation: genetic diversity means the different kind of gene pool amongst the species and different kind of gene leading to variations and in case of tasmaniandue to contagious cancer known asDFDTthru
got inability to mount an immune response and to reject these tumor The whole genome analysis of two animals originating from extreme Northwest and Southwest tsamania the maximal geographic spread together with the genome from a tumor taken from one of them.