Genetically Diverse Parental Genes Produce Taller, Smarter Children, Says Study

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Scientists have found that predecessors who are taller and generally more intelligent are a result of mixing genetically diverse DNA.

In the study published in the journal Nature, researchers found that children coming from two genetically unrelated parents are taller, more intelligent, and have the tendency to attain a higher level of education as a result of their predecessors sharing fewer genes.

The research was based on the health and genetic information from around four continents across the world.

However, the study found that the increasing genetic diversity in humans appears to have no effect on health factors such as cholesterol levels or high blood pressure, which could affect a person's health over the course of their lives.

"Most people would believe a diverse gene-pool is a good thing, but the discovery that height is associated with diversity wouldn't have been foreseen," Nathan Richardson from Medical Research Council said via The Guardian.

Researchers used data collected to measure 16 biomedical traits. They found that only four traits - height, general cognitive ability, lung capacity, and educational attainment - were associated with genetic diversity, according to the Independent.

"We've found that the genetics are associated quite robustly across populations and although we tried to compensate for environmental factors, we think the genetic effects are real," said co-author Dr. Peter Joshi of the University of Edinburgh.

He and his colleagues attempted to adjust the results by different environmental effects such as socio-economic status which ultimately made little to no difference to the data.

"There has been speculation ever since Charles Darwin that genetic diversity would be beneficial in terms of evolutionary fitness. We think genetic diversity decreases the chances of inheriting defecting copies of the same gene from both father and mother," Dr. Joshi said.

The results suggest that "outbreeding" is necessary and advantageous for humans, according to James Wilson of the University of Edinburgh, a co-author of the study.

According to researchers, the study suggests that height and cognitive ability have been favored as the main characteristics of evolution for generations, spanning different continents such as Asia, Europe, and Africa.

"A smarter prehistoric man would have a survival advantage, and we can of course imagine circumstances where the taller you are the better chance you have of surviving," Wilson said.

He added that the international study has given them insight to fundamental data about the evolutionary history of humans.