Amerika

Nature provides a few really solid metaphors. The cycles of the seasons, the use of repeated patterns in novel ways, and the presence of parasites. If any concentration of nutrients, wealth, power, or status exist, those without a positive goal of their own will show up to feed.

Apparently nature has decided to extend the metaphor. Whatever structures exist in the parasite can transfer to the host when it is weakened, gradually making it into something new, possibly something cancerous and moribund.

It turns out that certain varieties of tapeworm can spread their cancer cells to you through parasitic activity:

Here we describe a man with HIV infection in whom samples from lymph-node and lung biopsies revealed monomorphic, undifferentiated cells. The proliferative cells had overt features of a malignant process, but their small size suggested a nonhuman origin. Proliferation in the immunosuppressed host may have allowed somatic mutations to accumulate in the H. nana stem-cell population, ultimately leading to malignant transformation.

It is left as an exercise to the reader to draw the parallels implied by the metaphor. Perhaps as we vacuum up populations, we absorb some of the behaviors that make them doomed, and then are unable to spot the foreign within us as well as among us.

Tags: cancer, metaphor, parasitism