Biocultural Evolution Still Affecting Humanity
The term biocultural evolution is a means of describing the influence of both biological makeup and cultural behaviors on human evolution. It also explains that the nature of these two aspects is that they are somewhat interdependent and influential on each other. There are many examples of how environmental surroundings have influenced evolutionary changes. Similarly, there are numerous instances in which biological factors have influenced cultural behaviors. Often times, evolutionary changes may take place as a result of both biological and cultural factors working together or occurring alongside one another, and this phenomenon is still happening to humans.
One example of how humans are still bioculturally evolving is the increasing rate of skin cancer. Various human activities, especially resulting from technology, such as air pollution, have created an ozone layer that gets increasingly weaker. Since the ozone layer helps to block both the amount and intensity of UV rays, when it is weakened, it is far less effective in doing so. Therefore, it makes the occurrence of both skin lesions and skin cancer much more frequent, as UV rays are what contribute to these outcomes. It does not help matters that there is also a cultural desire to be tan. This means that humans who indulge in this desire by spending time in the sun, in fact contribute to the frequency of skin lesions and skin cancer in themselves.
Another example of biocultural evolution at work today is the number of teeth in humans. First, due to diet, wisdom teeth are essentially useless to present-day humans. As our biology progressively adapts to this circumstance, more and more humans go through life without ever developing wisdom teeth. The majority of those who do, must get them taken out, as their mouths are not designed with enough space for these teeth to grow correctly, and their presence usually causes pain as well.
A third example of biocultural evolution today is the post-reproductive cycle of human life, namely menopause in women. As little as 50 years ago, most females did not experience menopause, as the human lifetime did not exceed the amount of time it would take to use all of a woman’s finite number eggs. Now, not only is menopause an expected part of a female’s life cycle (and at around the same age), but females also experience an increasingly longer period of infertility. This is because as lifetimes increase due to technology, so then does the number of years after the menopause age. If lifetimes continue to increase, so will the period of infertility after menopause.
Yet another instance of biocultural evolution is due to the presence of white flour in foods, especially in Western civilizations. White flour encourages insulin manufacturing in the body, and in fact, may cause the body to produce more insulin than it needs. The result is the disease called diabetes which causes an over-reactive pancreas which produces too much insulin, and a gene which predisposes humans to diabetes gets passed to new generations. The outcome is births of newborns with Stage 1 diabetes and others humans possessing a predisposal for the disease, which will likely surface at some point in their lifetime. In fact, the has the highest rate of Stage 1 diabetes in the world, and this seems to be an increasing number here, as well as globally.
In addition, biocultural evolution takes places in the form of lactation periods. In some countries, especially in Western societies, lactation periods are growing increasing shorter. In hunting and gathering societies, breastfeeding may last anywhere from three to five years, yet in Western civilizations it can last as little as a year or even just months. This is because in Western civilizations it is not as widely accepted to breastfeed, and it is also culturally undesirable to breastfeed for more than a year due to career and financial concerns. In essence, culture determines the popularity and longevity of breastfeeding, and this culturally-determined time period becomes a biological fact in women. Western women become able to breastfeed for only about a year, whereas females in other civilizations maintain their ability for a longer period.
Problems like high blood pressure and heart disease are also outcomes which are still evolving from cultural factors. As technology has promoted increasingly sedentary lifestyles, the body loses its capacity to burn calories and maintain healthy function. In addition, diets rich in processed ingredients such as white flour and saturated fats, increase fat storage. Both of these factors increase obesity rates and decrease the body’s ability to maintain healthy function. High blood pressure, high cholesterol, heart disease, and other problems, are directly linked to modern diets and being sedentary. The outcome is that not only do these problems surface in humans, but genes are passed through each generation which pre-dispose people to these issues.
A seventh way in which biocultural evolution continues is in the recently increasing rate of bacterial diseases. Due to human creations like antibiotics and their overuse, bacterial diseases have encountered adaptations which render them immune to many of these antibiotics. Therefore, the human race is now re-encountering these diseases once again and in greater frequency, and our bodies are once again experiencing the effects of these diseases. This gradually affects longevity and overall well-being and health of humanity.
Finally, continuing biocultural evolution can be seen in the overall fact of our human longevity. The average age of the population and the average length of life both grow increasingly. This is due to technological advances in medicine and other related areas which combat infectious disease, genetic defects, and the like, which might otherwise kill humans.
