It is often said that through innovations in science, medicine and agriculture, humans have become the masters of their biological destiny. Humanity has gained control over its own evolution, eliminating most of the causes of death and suffering experienced by our ancient and not too distant ancestors.
Fighting hunger
We have eliminated hunger and food shortages in most parts of the world. Today we have access to a huge amount of high quality food products. The food that was previously only available seasonally is now on our tables all year round.
Getting rid of diseases
Humans have tamed many deadly diseases with antibiotics and even eradicated some of them entirely through vaccinations. Although we age and our body often wears out, we have many opportunities to heal it and even replace some organs with artificial ones.
Promotional video:
Birth control
People can control their own fertility and decide whether or not they should have children, even while maintaining an active sex life. If we wish, we can postpone the birth of children until we are ready for it, both financially and emotionally. Therefore, many people decide first to build a career, and only after that create a family and raise children.
Many of us can choose when and with whom to marry. Now there is an opportunity to start a family with a person from any part of the planet, and not just with peers living in the neighborhood. Moreover, many people have been able to marry members of the same sex.
Increased longevity
We have expanded the boundaries of life expectancy significantly: more people are living much longer than ever before. Across the planet, the number of centenarians will only increase every year.
Overpopulation
And with all these changes in culture, health, nutrition, and life expectancy, the population has grown substantially over the past century. It took hundreds of thousands of years for the population to grow to a billion people, but by the middle of the last century there were already two and a half billion. Moreover, there are speculations that by the middle of the twenty-first century, this small blue planet will have nearly 10 billion people.
Influence on the evolution of other species
We are not only rewriting our own future, but we are also influencing the evolution of millions of other species. First of all, the microbiome of our bodies has changed significantly due to the introduction of new foods and drugs into the diet. We also affect many species through pollution, deforestation and over-exploitation of nature.
What impact could all of these changes have on our future as a species? What will be the further course of our evolution?
Impact of choice
Geneticists have found direct evidence that our choices can have a profound impact on the evolution of the entire population, and ultimately our species.
There are some striking examples of this state of affairs. It turns out that both women and men in many societies now decide to have their first child at an earlier age. Other studies have shown that women are at a later age at the birth of their last child in some pre-industrial groups. At the same time, the age at onset of menopause in some post-industrial populations has increased significantly.
However, other studies have shown that women get significantly taller in at least one preindustrial group, but decrease in postindustrial women.
The trend towards early puberty with smaller body sizes may be due to the widespread decline in adolescent mortality as a result of improved hygiene, health care and medical care.
Modern evolution through the eyes of scientists
An interesting study published this year by a team of scientists led by Yair Field of Stanford University looked at the DNA stored in the UK10K project to look for signs of the recent evolution of people living in Britain.
The team investigated changes spanning the past 2,000 years and found evidence for evolution in three important sets of genes.
First, there have been changes in genes for lactase, or those associated with a person's ability to digest milk and other dairy products.
It turned out that milk tolerance has been on the rise in the last couple of thousand years in the UK, possibly along with an increase in milk consumption.
Changes have also occurred in the HLA genes, which play an important role in the human immune system. While the possible cause is still unclear, it could be due to the increased exposure to infectious diseases due to the large numbers of immigrants such as the Romans who settled in the UK about 2,000 years ago and many groups after them.
But most surprising was the discovery that the genes responsible for blonde hair and blue eyes have been dominant for the past two millennia. In this case, it seems that sexual selection, rather than natural selection, increased the number of people carrying the genes for this combination.
In the UK, at least, it seems that men really do prefer blondes, well, at least for the last 2000 years.
Far from being esoteric, this kind of research shows how the decisions we make about lifestyle, food, and mate choice can have long-term consequences for our evolution.
This is why we really need to think about the implications of our modern lifestyles and the profound changes we are making on the planet, all of which can affect our evolution.
Anna Pismenna