The world today is overrun by human technology and pollution. Forests are chopped down and covered by asphalt, and rivers are filled with poisonous byproducts. It seems humans have created an enormous gap between themselves and their closest living relatives. Humans are not subject to the forces of evolution in the same way that all other organisms are, because they adapt technologically, instead of evolving biologically.
To understand the significance of this difference, one must understand just how different humans are biologically from their nearest living relatives, the chimpanzees and bonobos. Human DNA is only 3-5% (the exact number is highly debated) different than Chimpanzee DNA, meaning humans share over 95% of their DNA code with chimpanzees. The three main distinctions used to explain Homo sapienís uniqueness are habitual bipedalism, larger brains, and dependency on tool use. It is important to understand that all three of these distinctions are a scale of how much more Homo sapiens do them. Chimpanzees and bonobos can walk on two feet, have brains nearly as large as our own, and have some tool use. They just donít do these things as well, nor as much.
It becomes apparent that biologically, chimps and bonobos are extremely similar to humans, and their mental and physical capabilities almost match that of humans. The main difference between humans and chimpanzees, which causes the vast gap in behavior, is the extent to which humans use and increase their technology. Chimpanzees and bonobos may use simple tools to get food which they normally could not have, but this tool use is rare and makes little difference in the survival of the primate. Their tools are also expendable. They may strip the bark from a twig, and use it as a tool, but as soon as they are done they will discard the twig and move on. Chimpanzees and bonobos never keep their tools with them. Humans, on the other hand, use their technology to adapt to any climate, situation, or habitat, and make tools that they will keep. This has a big impact on the survival of the humans.
This is what makes humans distinct, and causes them to escape most of evolutionís grasp. Instead of evolving to survive new circumstances, humans use their technology to adapt. If the temperature drops drastically, instead of evolving and growing thick fur and obtaining more body mass, humans would develop new technology such as warmer clothes, and sources of energy that produce heat. In a sense, humans have replaced biological evolution with technological evolution, because it is much more efficient, and allows for intended changes, rather than random chance. One driving force that allows for such effective technological evolution is a spoken and written language. Once humans could pass information on through mere words, instead of teaching through actions, the technological advancement could flourish.
In biological evolution, an organism must wait until an offspring has a random chance mutation that benefits it in some way, before it can evolve and become better. However, without the limitations of time and randomness, human technology can evolve quickly and exponentially. Following natural selection, this technological evolution is far more efficient than regular biological evolution, so the effects of biological have no advantage and are not passed on. These random chance mutations are ignored and useless, because some form of human technology is better and much more efficient. This seems to imply that humans no longer evolve biologically, and that humans are no longer subject to the forces of evolution.
However, regardless of technology, biological evolution can still take place. When adaptation is not possible, or technology is not developed quickly enough or efficiently enough, a change to the environment can cause biological evolution. For example, if a plague strikes a population and only a small percentage of the population has some genetic mutation that makes them immune to or at least resistant enough to the plague to survive, those humans will live to reproduce, and evolution on a microscopic scale has occurred. These drastic changes in environment are rare enough and the biological changes subtle enough that they would probably not be enough to cause speciation with humans.
Another way in which evolution can still occur in humans is sexual selection, although technological advancements in the altering of physical appearance limit this possibility. Ideally, men with more favorable features and attributes such as strong stature, high intelligence, and capability to support a family would be chosen by females to reproduce with, and humans would evolve towards better traits. However, modern technological advancements such as plastic surgery and complex societies have removed a large portion of sexual selection. Traits that would affect survival are not needed as much due to our large societies, and physical traits are easily altered with makeup, surgery, supplements, and training. Simple inherent traits are very rarely viewed as important enough to cause evolution, and what evolution does occur is so minor and so rare that its affects canít be seen.
While humans do still evolve biologically, it is only under special and rare occasions, and the evolution is minor. Rather than evolving to be better fit to survive changes in environment, humans tend to adapt with their technology, while keeping the same biological structure. Human DNA may only have a difference of 3-5% from chimpanzee DNA, but somewhere in that 3-5% is the ability to develop technology to adapt to almost any situation. There are some unfortunate consequences on nature as human adaptation becomes more and more of a burden on the environment, and humans can only hope it is not this great ability of adaptation that ultimately ends humanity.