Now I can’t imagine what must be going on in your head reading this title. Am I going to discuss how evolution is regressing? Am I going to discuss how evolution has come to a complete halt? What is evolution? Is humanity doomed? You should know how this blog works by now, you read and find out throughout the post. Before we get into the main idea’s of this post, there are some things we should probably define and discuss.
If you have ever taken a basic, highschool level biology course, than you have probably heard about a particular man by the name of Charles Darwin. Darwin is a naturalist, a person who studies natural history. Darwin is most famously known for his contributions in the theories of evolution.
Evolution is extraordinary. This is how nature has its fun. Unfortunately, evolution is not something that can be described in simple terms, as it’s not a simple phenomena. Evolution is the gradual change of the genetic composition of a species, brought on by mutation, genetic drift, and natural selection. By genetic composition, I mean the genetic blueprint. The fact that we humans have two arms with hands that have five fingers, is written in our DNA. By gradual, I mean it doesn’t happen over night. Evolution is a process that takes thousands of years. Take the human appendix as an example. Many researchers say the appendix is a vestigial structure (vestigial meaning that it has lost its original function), that was once used by our ancestors to digest leaves. Since over the course of thousands of years the human diet has changed, the appendix was no longer needed and evolved into a smaller, less utilized version.
Mutation, genetic drift, and natural selection are all means by which genetic changes in a species occur. Mutation is exactly what it sounds like. Somewhere along the process of fertilization (where an egg cell and a sperm cell combine to create a zygote), something goes amiss. Perhaps a particular gene spontaneously changes composition. In a totally random event, one particular unit of the DNA double helix structure changes and in turn, a seemingly normal grizzly bear gives birth to a white cub (known as the kermode bear). As this one kermode cub grows older and bears its own offspring, it passes along the mutated gene allowing for the mutation to expand into a large population of its own. Eventually, assuming the white hide is advantageous, the population of kermode bears may equal, or even surpass, the population of brown grizzly bears. If we assume, in a hypothetical situation, that the kermode bears face a greater chance of survival than the grizzly bears, less grizzly bears will bear offspring. Perhaps because the female bears visually prefer other kermode bears, or perhaps because grizzly bears are decreasing in numbers. In this case, the genetic composition of a population is shifting due to lack of mating and a decrease in the number of grizzly bears. This is known as genetic drift. Genetic drift typically occurs in smaller populations where a lack of mating, or rapid decline of a particular genotype, is most felt.
Lastly is natural selection, what Charles Darwin is most famously known for discovering. As organisms are born generation after generation, they mutate and develop new characteristics that may allow them to be better suited to their environment. Better suited organisms survive disasters better than their counterparts and can then reproduce and pass on their genes to future generations. Without knowing it, these organisms are being shaped by natural selection. Nature is hand selecting the adaptations that allow an organism to survive its ever-changing environment allowing it to reproduce and pass on those very adaptations, eventually creating a more evolved species. You might be more familiar with natural selections younger sister: Artificial Selection. Where natural selection stresses adaptations that allow an organism to better survive and reproduce, artificial selection stresses adaptations that we as humans find more desirable. Humans cross-breed particular dog breeds that are more or less aggressive, have a long or short tail, have long or short fur that is curly or straight. The same is done with plants and crops.
The purpose of natural selection is to shape organisms into survivalists so that they may reproduce and pass on their advantageous characteristics onto their offspring. But has the human race gotten in the way of evolution? Is the human race too scared to evolve? Or is it the contrary, are we too eager to evolve? When faced with a physiological issue, we seek help from medical practitioners to heal us. Whether we get the flu and need a vaccination, break a leg and need a cast, or develop cancer and need chemotherapy, we always seek medical treatment. Of course, the first two are as easy as allowing time (or nature) do its thing, while the latter requires medical assistance beyond natures power. Perhaps diseases of this kind are natures way of ridding the world of organisms that shouldn’t survive. Perhaps, this is natural selection working before our very eyes. Those with the genes of a stronger immune system will thrive, while those without will perish. Is modern medicine getting in the way of natural selection? Is modern medicine partaking in artificial selection? (Perhaps there already is a cure for cancer, and doctors are just milking you for your money) Even then, it’s a far stretch to say they’re selecting what disease will kill us and which won’t (since their goal is to treat all of them). How can we be sure that a cure for cancer won’t evolve from within us, whether it’s from our brain or our immune system? Without nature running its course, how can we evolve as a species from within ourselves rather than from external aid? Pathogens evolve, and in turn so does the medical practices to overcome these pathogens. What happens to the middle man (or in this case, middle human)? Maybe we’re damned to live in a disease ridden loop until a catastrophe destroys our everyday medical equipment and we’re forced to evolve a stronger immune system.
Cue the terminators.