A self-propagating, parasitic, cellular mass
I just finished reading David Quammen’s article in the April 2008 issue of Harper’s, “Contagious cancer: The evolution of a killer”. The gist being: cancer evolves, and is demonstrated as being highly infectious in Tasmanian devils.
Poor devils, their relative physical isolation has created an inbred population whose members are genetically very similar – and vulnerable – to a cancer transmitted during mating known as Devil Facial Tumor Disease (DFTD). Not sexually transmitted in the traditional sense, but rather DFTD is a cancer spread by the habit of mutual face-biting during courtship (and so forth).
In humans, cancer is a very unique affair. My tumors would be derived from my own cells, growing unchecked. Henry’s cancerous tumors would be made of his own cells, as would yours. DFTD tumors found on the devils were all genetically identical to one another and distinct from their host. While not quite a distinct “species”, DFTD is a self-propagating, parasitic, cellular mass. As such, DFTD is undergoing cellular replication, environmental selection and epigenetic expression. DFTD may not be a living organism, but as a genetic conglomeration it is evolving.
As Quammen smoothly knit these concepts together, I bumped along on a shuttle during my commute home from work. The proverbial light bulb went on above my head, and I felt a tightness in my stomach. “What if…”s began bubbling up from parts of my brain I’d long considered dried up. Suddenly ideas and questions came to mind, and – more shockingly – the motivation to learn more.
Now I’m looking into topics integrating genetics, evolution, ecology and disease, and reading about research laboratories at university.