According to a new study, Tasmanian devils have had a rapid revolutionary response to a highly contagious cancer that had threatened to make the species extinct.
Scientists have discovered that Tasmanian devils have evolved a resistance to the face cancer within a few generations. The full results of the study were published in the journal Nature Communications.
Tasmanian devils evolve resistance to cancer
The unusual disease has already killed 80% of the Tasmanian devils on Earth, but the study provides some hope that the species could survive. A team of international researchers came together to study how the genetics of the species has changed over time, including before the cancer took hold, and found that Tasmanian devils had evolved to combat the disease.
In 1996 the facial tumors were identified for the first time. It was found that when the animals bite each other, they spread the cancer cells and cause deformations on their face in the form of growths. The cancer was observed to kill most animals within 6 months, and has been affecting populations for almost 20 years.
Over the course of this latest study the researchers looked into the genomes of 300 Tasmanian devils from three distinct populations. The aim was to identify any genes that had changed in frequency as time went by.
Study authors researching genetic changes
“Our hope was that we would find some genes that were perhaps associated with cancer or resistance to cancer or immune function,” Andrew Storfer of Washington State University and the study’s co-author, reportedly said. “And in fact we did find seven different genes in two small regions of the genome that seem to have implications for cancers in other animals, including humans.”
The team believe that these genes may be responsible for telling the immune system to identify and fight cancer cells. All three populations showed the same changes, which eliminates the possibility that the process was down to chance.
The study provided a view of evolution in action, because the Tasmanian devils that survived were the ones that were able to pass on their genes. As a result these genes are increasingly seen in the global population of the species. Consequently the cancer is selecting the animals that are best at fighting it by killing off the other Tasmanian devils.
“It is really remarkable, the fact that we are able to use this modern sequencing technology to find these needles in a haystack across the genome,” says Paul Hohenlohe, a genomicist at the University of Idaho and one of the study’s co-authors.
Remarkable story of evolution
Co-author Storfer later added that the next stage of research was to work out the function of the genes. Researchers are growing facial tumor cells in a laboratory and modifying the genome in order to better understand how the growth of tumor cells is influenced by the genes.
It is not likely that genetic changes would afford Tasmanian devils complete resistance to cancer, but it may give them sufficient time to reproduce. “This gives us hope for the survival of the Tasmanian devil, which was predicted to be extinct but isn’t,” Storfer said.
Fellow study author Professor Menna Elizabeth Jones called the research “groundbreaking.”
“They have developed resistance within four generations, which is eight to 12 years. This is unprecedented,” said Jones. “The devils might just be able to save themselves.”