Newswise – Contemporary humans are still evolving, but natural selection favors those with lower incomes and lower education – according to a study from the University of East Anglia.

A new study published today shows how the effects of natural selection are stronger in lower-income and less-educated groups, in younger parents, in people not living with a partner and in people with more sexual partners at home. life.

Meanwhile, natural selection opposes genes associated with high education, high income, low risk of ADHD or major depressive disorder, and low risk of coronary heart disease.

Lead researcher Professor David Hugh-Jones, from the UEA School of Economics, said: “Darwin’s theory of evolution states that all species develop by natural selection of small inherited variations. that increase the individual’s ability to compete, survive and reproduce.

“We wanted to know more about the characteristics selected for and against in contemporary humans living in the UK.”

The research team looked at data from over 300,000 people in the UK, taken from the UK Biobank – a long-term project investigating the respective contributions of genetic predisposition and environmental exposure to the development of the disease .

The team studied the participants’ polygenic scores – an estimate of a person’s genetic responsibility, predicting a person’s health, education, lifestyle or personality.

They looked at two generations of people living in the UK, using data on the participants’ number of siblings as well as their number of children.

David Hugh-Jones said: “We found that 23 out of 33 polygenic scores were significantly related to whether a person had more or fewer children in their lifetime.

“Scores correlated with lower income and education predicted having more children, which means that these scores are selected from an evolutionary perspective.

“Scores correlated with higher income and education predicted having fewer children, meaning they are selected against them.

“The effects were particularly strong among people with less education and low income, and among people not living in a couple. In older mothers, the effects were actually reversed – in this group, scores corresponding to higher gains were selected.

“We explain these patterns using the economic theory of fertility, which was first developed more than 60 years ago. If you have genes associated with higher income, this has two opposite effects.

“It makes you better, so you can afford more kids. But it also makes it more expensive to spend time on childcare instead of your job, because you’ll lose higher wages.

“The first effect causes people to have more children, the second effect causes them to have fewer. At the lowest incomes, this second effect is more powerful. This explains the results we see.

“Our explanation shows how economics and genetics can work together.

“Natural selection could make society more unequal, by increasing the correlation between income and polygenic scores, including scores that predict health and education outcomes.”

The research was conducted by UEA in collaboration with Abdel Abdellaoui, a geneticist at the UMC Medical Center in Amsterdam.

Human capital mediates natural selection in contemporary humans” is published in the journal Behavioral genetics July 6, 2022.