What are the consequences of caveman genes interacting with the modern environment… radically different food, new technology, petro-chemicals, artificial light, drugs?
Novelty and extreme environments often cause disease. Perhaps we are optimized for a Pleistocene environment. Lecture tomorrow will explain how a variety of illnesses occur because of our caveman genes. Not that being a caveman is a bad thing! Caveman physiology continues to serve us well in many ways, especially if we avoid particularly dangerous new exposures.
Can we predict which exposures might be dangerous? Perhaps, if we recognize that mismatch often occurs because of mimicry.
For example, altitude illness occur because of mimicry of infection. High altitude pulmonary edema resembles pneumonia.
Drugs of abuse, like cocaine, valium, marijuana, heroin, mimic endogenous neurotransmitters, or manipulate neurotransmitters that trigger reward pathways in the brain.
Artificial light is a mimic of natural sunlight – a concept that has consequences for melatonin production, the stress response, and cancer.
Close-up reading – of books and especially computer screens – mimics the near horizon. Caveman eyes that would otherwise spend 90% of the time at a distant focal point are entrained to close-up work – altering the development of the lens, eye shape, and retina.
Marketers and manufacturers often exploit caveman physiology. Gambling elicits the same reward pathways as recreational drugs. Casino gambling exploits the brain mechanisms that reward multiple small investments of time and effort with success in hunting and gathering, except that they artificially minimize the perceived costs and exaggerate the rewards.
Tomorrow we will focus on extreme environments and the diseases that accompany SCUBA diving and especially mountaineering.
We will discuss how prolonged exposures to new environments can eliminate gene-environment mismatch. Many generations at altitude have allowed the Andeans, Tibetans, and Ethiopian highlanders to cope with the challenges of an extreme environment.
See you soon!
Emergency Physician, Educator, Researcher, interested in the microbiome, evolution, and medicine