The latest study has shown that uman beings are still evolving, explaining how future generations will become shorter or taller, develop different physical characteristics, and even have different genes.
Despite the progress of civilization, many of the pressures of natural selection that shaped human populations for thousands of years—such as disease, famine, and harsh environments—have been greatly reduced thanks to advances in medicine, improved sanitation, and more reliable access to food.
However, Dr. Jason Hodgson, an evolutionary anthropologist and geneticist at Anglia Ruskin University in the United Kingdom, emphasizes that human evolution is still taking place today.
Human Diversity
Briana Pobiner, a paleoanthropologist who studies human evolution at the Smithsonian National Museum of Natural History in the United States, says that diet has played a crucial role in the evolution of modern humans.
“About one-third of the world’s population today can digest milk as adults, whereas between 5,000 and 10,000 years ago, no one could. This is an evolutionary change that happened remarkably quickly,” she says.
She explains that this change occurred after humans began domesticating milk-producing animals.
During periods of famine, people who could digest milk—which is rich in fat and protein—were more likely to survive and pass those genes on to their children.
As a result, the genes spread rapidly throughout populations.
When humans migrated out of Africa to different parts of the world thousands of years ago, they encountered different climates.
This led to the development of new physical traits that helped them adapt to their environments.
For example, lighter skin evolved in regions with lower levels of sunlight, helping the body produce enough vitamin D.
Dr. Hodgson explains that these regional differences arose because human populations became separated.
“Today, we’ve come back together in many different ways through migration, globalization, and other factors.
“Hodgson studies what is known as assortative mating, which he describes as the tendency for individuals to choose partners who are more similar to themselves than to others.
He says assortative mating can reinforce natural selection already taking place and help preserve certain traits in humans.
Researchers have found, for example, that the taller a person is, the more likely they are to have a tall partner.
He adds that height, weight, facial structure, and other characteristics tend to cluster within certain groups through reproduction, ultimately influencing the frequency of genes in the population.
“There are many different factors continually influencing human development,” Hodgson says.
What Does It Mean to Be Human?
Some choices we make do not affect our genetic evolution.
For example, Pobiner says: “If you exercise and build large muscles, that doesn’t mean you’ll pass genes for big muscles on to your children.”
Today, from orthodontic treatments to cosmetic surgery, many physical traits can be altered during a person’s lifetime to better match social ideals of appearance.
Globally, around 38 million cosmetic surgical and non-surgical procedures were performed in 2024, according to the International Society of Aesthetic Plastic Surgery.
This represents a 40% increase compared with 2020. Thomas Mailund, a former associate professor of bioinformatics at Aarhus University in Denmark, says this ability to change our appearance means that our bodies no longer necessarily reflect what our genes originally prescribed.
Gene Editing and the Future
In the future, changes may go beyond appearance, as scientists continue developing gene-editing technology known as CRISPR, which essentially works like molecular scissors.
One component identifies a specific section of DNA, while another cuts or modifies that section.
The technology has already advanced enough to treat a small number of genetic diseases, including certain blood disorders.
If it continues to improve and becomes widely available, it could one day alter many human traits at the genetic level, potentially changing future generations.
If these genetic changes were made in reproductive cells—those that produce sperm or eggs—they could also be inherited by future generations.
However, scientists are still far from being able to do this safely and reliably.
The technology also raises many ethical concerns, including the possibility of creating so-called “designer babies,” reinforcing discrimination against people with disabilities, and many other moral questions.
Hodgson says:”There is a global consensus today that this is not something that should be applied to humans, and it is fundamentally unethical.”
If the technology became widely available, it could even allow parents to choose their children’s physical traits by modifying genes to select desirable characteristics.
A New Species
Mailund says it is difficult to predict what humans will look like in the future without knowing how our environment will change.
If we look far enough into the future, humans might even evolve into an entirely new species.
One million years ago, human species such as Homo erectus walked the Earth. Our own species, Homo sapiens, appeared only about 300,000 years ago.
“So wait another million years, and our descendants may differ from us evolutionarily as much as Homo erectus differs from us today,” Mailund says.
However, he cautions that the differences between species may not be as obvious as we imagine.
It is also possible that our species could split into two, if some humans were to settle in entirely new environments—such as outer space.
