Assessing the Future of Human Evolution

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"Assessing the Future of Human Evolution"
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There is ALWAYS evolution occurring. It is a built-in mechanism in the transmission of our DNA. Although we can't stop it, we can try to understand it better. To know the future of human evolution, we need to determine what the present and future environmental pressures on humans are since evolution is guided by the environment we live in. The processes of evolution occur over long periods of time in response to these pressures. When environmental changes occur too quickly to adapt to, such as was the case with dinosaurs, extinction can occur.

When you think of the pressures we as a species are responding to today , a number of things come to mind and can be categorized into three general categories: physiological, social, and psychological.

Let's use an example most people have some familiarity with; the percentage of carbon dioxide in the air we breathe. Most people know about this through the concept of "greenhouse effect." Usually we think of carbon dioxide in the context of weather and climate change. Humans, however, breathe a mix of gases that have certain percentages of carbon dioxide, oxygen, nitrogen, and others. Humans have evolved to operate maximally under these percentages of gases. Over thousands of years, if these percentages change, some humans will not be able to survive. Those who have adapted to the changing mix of gases in the atmosphere will survive and reproduce, leaving progeny who are better adapted.

So how might this adaptation have happened? When we reproduce, we send our children our DNA. In this transfer, our DNA can have minute changes. Sometimes these changes can be destructive such as when an important protein isn't produced and the child is born with PKU which can be life-threatening and/or produce cognitive disabilities. However, sometimes these changes can also be accidentally beneficial. To use our greenhouse gas example, suppose that some small change in DNA created a change in a property of the child's blood that allowed him to breathe lower amounts of oxygen than other people? In an environment where oxygen is less available, this child would then have an advantage over other children who didn't have this change. This child would be more "fit" and be more likely to reproduce and pass on this genetic characteristic.

This example implies that these changes happen over many generations and hundreds and thousands of years. It also shows that evolution is significantly "accidental" and that genetic change just as often can have harmful effects on adaptability.

What environmental pressures is our genetic machinery responding to now that will result in future evolutionary changes in humans? Clearly, ours is an increasingly technological and scientifically oriented world. To me, this points to success for brains that are more conceptual, able to "multi-task," and better able to manage sensory overload.

In the social sphere, with the world population burgeoning, people who have the emotional and psychological ability to respond to higher densities of people without withdrawing or becoming aggressive will be more successful in passing their genes on.

Finally, the success of our species has become increasingly reliant on our creative response to adversity. Events that might lead to extinction in other species has spurred humans to develop new ways to adapt. Our ability to look to the future and predict things that can hurt us allows us to circumvent extinction before it happens. Perhaps our "innate" urge to look to the other planets in our solar system and beyond as new worlds to inhabit is an expression of our evolutionary development.

More about this author: Jim Mcfalls

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