Crossword puzzle and explanatory text designed and written by Aidan Schmall.
Tasmanian devils suffer an infectious strain of cancer called Devil Facial Tumor Disease (DFTD). This cancer is caused by the transfer of cancerous cells from one devil to another during biting. DFTD is highly contagious in these animals and it has been estimated that 80% of the Tasmanian devil population has been wiped out since the discovery of this disease. One specific devastating feature of this transmissible cancer in Tasmanian devils is Localized lineage replacement (1). This is the phenomenon where due to the identical cancer cells that spread rapidly throughout this population, genetic diversity within the species decreases because of the identical cancer cells presence within the organisms. On top of this phenomenon, there are in fact two separate strains of transmissible cancer identified in Tasmanian devil (2). The presence of two strains further endangers Tasmanian devils as it allows for convergent evolution to occur of these two separate strains. Convergent evolution is defined as the independent evolution of two similar species occupying similar niches. Convergent evolution typically results in analogous structures in species, an example of convergent evolution would be how complex eyes developed within vertebrates, cephalopods, and arthropods.
Once DFTD has been contracted by a Tasmanian devil, recovery is almost impossible as tumors begin to expand rapidly within the organism. Not many possible treatments have been presented to solve this issue, however some strategies as to how to isolate a Tasmanian devil once it has contracted DFTD have arisen. Researchers have started to resort to this method of isolation rather than treatment because cancer as a disease is very aggressive, especially the DFTD strain. Once Tasmanian devils have contracted DFTD, they typically decrease all social interactions due to the taxing effects cancer takes on one’s body.
Tasmanian devils contract DFTD through contact with other members of the same species who already have the disease. Tasmanian devils typically transmit DFTD through biting, an extremely common behavior among Tasmanian devils as the majority of interactions this species shares with members of its species are competition related (mating or food). This gives plenty of opportunities for recently affected Tasmanian devils to transmit this cancer to any other member of the species it interacts with before it is immobilized from the pain of the cancer (3).
I believe it is imperative as the human species grows so rapidly that we take time and use our resources to help other animals we share the planet with. All these animals can suffer diseases as severe and painful as ones we humans can be afflicted by. It is our responsibility to maintain and uphold the gift of nature that surrounds us. As humans we are extremely lucky to not have to worry about an infectious strain of cancer as Tasmanian devils do.
References
- Hamede RK, Pearse AM, Swift K, Barmuta LA, Murchison EP, Jones ME. Transmissible cancer in Tasmanian devils: localized lineage replacement and host population response. Proc Biol Sci. 2015 Sep 7;282(1814):20151468. doi: 10.1098/rspb.2015.1468. PMID: 26336167; PMCID: PMC4571705.
- Pye, R. J., Pemberton, D., & Tovar, C. (n.d.). A second transmissible cancer in Tasmanian devils. PNAS. from https://www.pnas.org/doi/10.1073/pnas.1519691113
- Hamede RK, Pearse AM, Swift K, Barmuta LA, Murchison EP, Jones ME. Transmissible cancer in Tasmanian devils: localized lineage replacement and host population response. Proc Biol Sci. 2015 Sep 7;282(1814):20151468. doi: 10.1098/rspb.2015.1468. PMID: 26336167; PMCID: PMC4571705.