A Disease of Wealth in Squirrels

Most people look at my research and see self-experimentation. I see a new way to understand diseases of wealth (often called diseases of civilization). We get sick because we live differently than our long-ago ancestors. Self-experimentation is powerful enough to sort through the thousands of differences between modern life and long-ago life to find those that matter.

In an experiment about the value of circadian rhythms to chipmunks, Patricia DeCoursey, a professor of biology at the University of South Carolina, found that their value was revealed by stress created by wealth:

In one experiment she discovered that chipmunks without an internal circadian clock appear quite normal at first. They can survive in optimal conditions; during the first year after their internal clocks were disabled, “predation by weasels was minimal,” she says. But then the chipmunk population increased strikingly due to two successive years of abundant acorn crops in the forest. The weasel population also increased, following the growth of the chipmunk population. Under these more crowded conditions, the restless nighttime movements of the arrhythmic chipmunks in their burrows clued the weasels in to their locations, and predation increased dramatically. The weasels killed all but four of the 100 chipmunks in this population.

3 Replies to “A Disease of Wealth in Squirrels”

  1. Just goes to show that science won’t always provide immediate conclusions for a simple manipulation. Sometimes what’s important is the interaction between the manipulation and the diversity of environments in which the manipulation can be expressed (checked). Our causal models usually start out simple (Cause–>Effect), but reality is often much more complex and therefore more subtle (Cause1+Cause2–>Effect, or Cause1–>Effect iff Cause2 is equal to or greater than some threshold value, etc.).

    Thanks for finding this!

  2. Even cancer may be linked to abnormal circadian rhythms:

    “A nationwide study in Denmark, for example, found that women who work mainly at night for at least six months are 1.5 times more likely to develop breast cancer than those who work regular hours (8). Researchers suggest that the raised cancer risk could be because these people’s cells start to divide at the wrong time and run amok, an idea supported by some cell-culture studies.”

    (for the reference, see chronotherapeutics.org/docs/press/circ/Nature_2009.pdf )

  3. Interesting. Or those working the graveyard shift get significantly less sunlight and therefore vitamin D which is also correlated (maybe causally related) to cancer. Though I don’t know how much vitamin D sun exposure in Denmark will produce. If it is a good source, it will only be during the summer.

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