What are related traits

Children of closely related parents : Inbreeding doesn't make you sick, but it makes you smaller

As meticulously as Charles Darwin collected arguments for his theory of evolution, he also listed reasons for his impending marriage: "Someone to love, better than a dog, his own home and someone who runs the household." Leisure researchers annoying visits to relatives. And most of all, he was concerned that close relatives to his future wife, his cousin Emma Wedgwood, would harm the health of any children.

Offspring think a little more slowly

A study of more than 350,000 people does not confirm Darwin's fears. It is known that the offspring of closely related parents have a higher risk of developing an otherwise rare hereditary disease. On average, they are also 1.2 centimeters shorter, think a little slower and statistically have 10 months less education, determined the team led by Jim Wilson from the University of Edinburgh. But the genetic monotony in the genome of people with closely related parents did not increase the risk of complex diseases that are influenced by many genes, the researchers write in the journal "Nature". For example, there is no measurable effect on high blood pressure, cholesterol levels and other factors that can lead to cardiovascular diseases.

Three of Darwin's children did not reach adulthood

This contradicts previous studies. For example, an analysis of the Darwin and Wedgwood families found a link between family marriages and child mortality. Of Darwin's ten children alone, three did not reach adulthood. But the analysis did not use genetic data and was limited to these two families.

The “Nature” study, on the other hand, analyzed the entire genome of hundreds of thousands of people from four continents in order to search for a connection between inbreeding and a dozen disease-related and other characteristics such as size or intelligence. Based on the distribution of 250,000 variable genetic components, the researchers were able to measure how many genetic segments inherited from mother and father of a person are identical and thus infer the degree of relationship between the parents. The researchers conclude that close relatives of the parents have a negative effect on characteristics such as size, lung volume, cognitive abilities and level of education. However, a connection with complex diseases cannot be recognized. For Darwin, however, this reassurance of his worries comes 133 years too late.

Now new: We give you 4 weeks of Tagesspiegel Plus! To home page