Many people believe that evolution has basically stopped in modern humans - in particular, because modern medicine and technology are saving people who would have died before and, therefore, are preventing the unfit from being eliminated. This is based upon a fundamental misunderstanding of evolution.

The Economist explains:

Evolution is not about progress. It is about adaptation. Sometimes adaptation and progress are the same. Sometimes they are the opposite. (Ask a tapeworm, which has “degenerated” into a mere egg-laying machine by a very successful process of adaptation.) If a mutation provides a better adaptation, as Dr Cochran thinks these disease genes did in financiers, it will spread.

Given the changes that humanity has created in its own habitat, it seems unlikely that natural selection has come to a halt. If Dr Deacon is right, it may even be accelerating as cultural change speeds up, although the current rapid growth in the human population will disguise that for a while, because selection works best in a static population. ...

The ultimate driver of sexual selection is the need to produce offspring who will be better than the competition, and will thus be selected by desirable sexual partners. Parents know what traits are required. They include high intelligence and a handful of physical characteristics, some of which are universal and some of which vary according to race.

If evolution is about adaptation to the environment, then changes in the environment will require adaptive changes if the species isn’t going to die out. We humans have the luxury of being able to change our environment to adapt to our needs, but our needs aren’t always the same as what we currently are — sometimes, our needs will be forcing changes in us, a unique situation in the history of life on our planet.

Medicine and technology aren’t slowing adaptation as some imagine because this is all part of our environment now. The ability of medicine to extend life beyond what would “naturally” happen is no different than the ability of social cooperation and human altruism to extend life beyond what would “naturally” happen if we lived alone in the woods. What is “natural” to us is the environment we create for ourselves.

 

Read More:

• Evolution vs. Creationism
• Science vs. Religion
• What is Evolution?