Toxic Chemicals; A New Evolutionary Pressure
Never having read Darwin in depth, I can only offer my simple summary of evolution as ‘natural selection and adaptation/descent with modification’ over long periods of time.
I recently finished reading Slow Death by Rubber Duck: The Secret Danger of Everyday Things.
My primary walk-away point:
Nothing is solid, especially human epithelium; the layer of cells that line the cavities and surface structures throughout our bodies. The epithelium, in its protective role, is more of filter than a barrier, and not a great one at that.
The cornucopia of chemicals, many of them toxic, that we are routinely exposed to; that we inhale, ingest (chemical foods, pesticides, etc, and drugs), touch (chemical fire retardants and stain protectors in furniture, household cleansers, laundry soaps, etc), and apply to our bodies (personal hygiene products) are absorbed by our bodies and enter our blood. We all, including newborns, have circulating levels of toxic chemicals in our blood; including mercury (from fish), BPA’s (from plastics and linings of canned products, etc.), phthalates (in shampoos, shaving gels, household products and children’s toys, etc.), and more. As the authors succinctly say, “We’re all marinating in chemicals every day.”
One part of the book I found fascinating had to do with the ubiquitous chemical, triclosan.
We live in a germ-phobic world and any fear can, and usually is, exploited for profit: create and build fear and sell the antidote. In this case, triclosan is the chemical industry’s Holy Grail anti-bacterial. As such, and as you would imagine, chemical companies are putting it everywhere, from hand soaps and toothpastes, to toothbrushes.
The simple point being that the daily use of normal household and personal hygiene products result in personal pollution that spikes the body’s blood levels of triclosan, and other chemicals.
When the author asked a scientist if he should be worried about the extremely high levels of triclosan in his urine the response was: “It shows that your body is working properly in removing triclosan. It is high for the moment. But, you should know that the human body usually adapts in the metabolism of triclosan.”
The authors go on to say: “The concept that our bodies need to adapt to synthetic chemicals is an interesting one. Given that triclosan is a human creation, the metabolic pathways necessary to break it down and excrete it are indeed things that our bodies need to learn how to do.”
The authors continue” The huge number of synthetic chemicals that surround us every day of our lives is creating a new kind of evolutionary pressure, a new kind of natural selection every bit as powerful as the process that resulted in human populations developing lighter or darker skin pigments in response to prevailing climatic conditions. Because of the increasing evidence that many human illnesses—including fatal ones like cancer—are linked to exposure to chemical pollution and because some people’s bodies are better able to adapt to and cope with these new environmental stressors than others , perhaps the human population is being culled by toxic chemicals.”
Whoa, and whoa again!! This is the essence of evolution, adaption and descent with modification; that some of us are ‘genetically predisposed to deal with the daily assault of toxic chemicals and some are not.’
The idea of genetic adaptation, modification and selection for toxic chemical hardiness or ‘immunity’ for survival is mind bending. That this survival mechanism of evolution has been ‘built-in’ since the first life forms, to adapt to an ever-changing environment, is the epitome of perfection.“There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one: and that whilst this planet has gone on cycling according to the fixed laws of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.” Charles Darwin, The Origin of the Species.