The Power of Microevolution
The most basic aspects of humanity like how we walk and how we speak are the result of evolution. Around 6 million years ago, early hominins began to walk on two legs rather than four. The human brain evolved to become larger and more complex, allowing for sophisticated language and tool-making. The way in which humans have evolved explains how we live today. However, the general conception that evolutionary changes occur over millions of years is only sometimes true. Evolution can occur in under a decade which is known as microevolution.
An image of two chromosomes.
Microevolution is better defined as changes in the frequency of a particular trait over a short period of time. A straightforward example of microevolution is in beetles, where the frequency of brown coloration increases from one generation to the next. Such a change could arise from a multitude of reasons, one being natural selection. Going back to our example of the beetles, if they found themselves in a less green environment, the number of brown beetles would increase, allowing them to blend into their environment better. Another cause for microevolution would be mutations which can cause completely new traits to appear within a population.
One of the most interesting instances of recent microevolution is a decrease in the prevalence of wisdom teeth. Studies are finding that the number of babies developing wisdom teeth has fallen over the past decade. Scientists are exploring a couple of hypotheses to explain why this is occurring. One possible explanation that has been introduced is the state of the food we eat today. As people are consuming more processed foods, specifically processed meats, they are consuming food that is also softer. So, humans no longer need to develop wisdom teeth to help them consume chewy and unprocessed meat. Additionally, the softer modern diet has caused the human face to decrease in size. Less room means less space for developing extra features, like wisdom teeth.
Scientists have also found that babies are being born with an extra artery in their arms in recent years. Originally, this extra artery developed while the fetus was in the womb to transport nutrients from the mother to the fetus. Once the child was born, the artery would disappear. But now, around one in three people keep the artery for the duration of their life. Scientists believe that the extra artery, which is transporting more blood to the arm, is because humans have found more use for their hands in the modern world as laptops and phones become a larger part of society. Rather than the legs being the primary limb, the sedentary lifestyle has led to a wider use of hands. For this reason, babies are also being born with extra bones in their legs.
Our world keeps evolving, and our bodies are evolving alongside it. However, what’s interesting is the rate at which we see our bodies adapt. Humans are adjusting rapidly to new technologies at a biological level. Our gene pool is shifting faster than ever to keep up with a world that is moving faster than ever. This creates human bodies that are genetically different from anything scientists have seen in a previous generation which goes to show the power of microevolution.
