In return, today we are presumably more likely to develop cardiovascular disease.

Just like plants and animals, man is a ‘dynamic organism’. This means that humans are also subject to evolution. And that is easy to see if you look at our distant ancestors. Not only do we look very different today, we also behave differently and now have a different diet. In a new study Nijmegen scientists have mapped out how modern European populations have evolved over the past 50,000 years. And that leads to a surprising discovery.


As mentioned, organisms constantly adjust their appearance (also called phenotype) during their lifetime. This appearance can be influenced, for example, by genetic factors, social and cultural habits, eating behavior and environmental factors. Scientists from Nijmegen have now investigated whether they could trace the development of some ‘complex’ human traits (that is, traits determined not by one gene but by tens to hundreds of genes) of modern Europeans from roughly 50,000 BC to the present day. The researchers were interested in, among other things, the development of the human intellect and body height, in addition to skin pigmentation, weight/BMI, fat metabolism and cardiovascular disease.

How do you do that?
You may wonder if you can track down all the genes that interfere with, for example, height. The answer is yes, using a technique called GWAS (genome-wide association studies). In that case, you take all of the human genes (the genome) to investigate which genes have an effect on height. Incidentally, there is no causal relationship (you don’t know exactly how those genes influence height), but there is a statistical relationship (the same genes always appear when determining height). In this way, in a large population study, you can obtain a list of genes that are involved in the height of the human body. You can then compare that list of modern Europeans with the genes of our distant ancestors. In the meantime, more than 800 people have been excavated whose DNA could be mapped. This gives you a kind of timeline of European growth genes, in which you can look for changes and turning points.

The researchers make a striking discovery. “In general, we see a clear difference of several features before and after the Neolithic Revolution,” said researcher Mihai Netea. The Neolithic is an important period in human development. This period is characterized by the transition from a hunter-gatherer society with an itinerant existence to an agrarian society of people who lived in settlements and engaged in agriculture and livestock – the so-called Neolithic Revolution. This resulted in a completely different way of life, change of diet, and different socio-cultural customs. “It’s as if there was an acceleration of the evolutionary processes then,” Netea said.


The researchers discovered, among other things, a clear increase in body size and reduced skin pigmentation. Europeans have kept their dark complexion for a remarkably long time, which actually only became lighter during this period. This may have to do with migration from Middle Eastern populations with lighter skin. In addition, HDL cholesterol – often referred to as ‘good’ cholesterol – appears to show a clear decrease. And that has far-reaching consequences. Because this increases the risk of arteriosclerosis.

Evolutionary advantage

The changes reflect ongoing evolutionary processes in humans. In addition, they emphasize the impact that the Neolithic Revolution had on our lifestyle and health. In addition, there is thus a change in genetic factors that leads to the development of coronary artery disease via a decrease in HDL cholesterol. And that raises a pressing question: what is the evolutionary advantage of those lower HDL-cholesterol concentrations? The researchers do have a suspicion. “Maybe it’s in the development of cognitive functions,” said researcher Yang Li. “That’s because cholesterol is fundamental to brain development and functioning. Variations in HDL levels have previously been linked to changes in intelligence, learning and memory.”

It means that today we are taller and smarter than our ancestors. But we pay a high price for that. In return, today we are more likely to develop cardiovascular disease. “These are hypotheses, not proofs,” Li underlines. “But it illustrates the importance of this research, in which we study the factors that can influence the development of complex human characteristics.”