Science Friction_ Where the Known Meets the Unknown - Michael Shermer [37]
Of course, we cannot overlook the fact that more older people get cancer, atherosclerosis, and Alzheimer’s, so obviously infectious agents alone cannot be the cause. As with most matters medical, there is an interaction between variables; in this case aging bodies with older and weaker immune systems are more susceptible to the actions of nasty germs. But it is the germs we should focus on in terms of control or eradication, says Ewald, not these secondary conditions.
Ewald’s heresy springs from the new science of “evolutionary medicine,” an approach recognizing that viruses, like people, evolve—witness HIV. The drug cocktails work only temporarily because the virus evolves strategies to get around the treatments. It is a constant battle between the host’s immune system and the pathogen’s survival strategies. Consider the herpes simplex virus that gives you cold sores. It evolved a clever strategy of living in your nervous system so that your body’s immune system cannot attack it (without also destroying the nerves, and in the process kill its host). To perpetuate itself, the herpes virus travels down the length of your nerves to endings in moist areas like your mouth and lips where, when you are under stress (during which your immune system is busy doing other things), it causes an open wound through which it can spread to new hosts through such activities as kissing.
In a similar fashion, the human papillomavirus hides in the genital tract and erupts in a herpes blister in the cervix, awaiting sexual contact. Even worse, the papillomavirus takes over cells of the cervix, causing them to replicate at a much higher rate than normal (in order to more rapidly spread itself by injecting its DNA into these host cells). A by-product of this accelerated cellular replication is that some mutate into cancerous cells that then spread. By the time the cancer kills the host, the papillomaviruses have spread to other hosts through sex, and so on indefinitely into the future. That is how evolution works, whether you are a virus or a human. Cancer is simply collateral damage of the virus’s survival strategy.
Like everything associated with the theory of evolution, evolutionary medicine is controversial and remains on the heretical fringes of mainstream science. Nevertheless, the human genome project has shown us that the evolutionary perspective cannot be ignored in any aspect of the human condition, and thus I give this heresy a fuzzy factor of .6.
Heresy 6. The Brain and Spinal Cord Can Regenerate
During the 2001 Super Bowl the actor Christopher Reeve generated considerable controversy when he appeared in a commercial that depicted him walking, despite a debilitating spinal cord injury that turned him into a quadriplegic. This sent a false message of hope, numerous advocates for the handicapped argued, because everyone knows that the brain and spinal cord cannot be regenerated. After a couple of weeks—months at most—injuries to the brain and spinal cord are permanent and irrecoverable.
This has been the medical litany for decades, but it may soon be changing. Neuroscientists around the world are racing to capture what would be one of the greatest prizes in medical history—repairing damaged brains and spinal cords, thereby releasing hundreds of thousands of people from the neuroimprisonment of quadri- and