White Skin May Have Evolved Much Later Than Believed
Genetic analysis of the remains of a Mesolithic man has toppled ideas about the lineage of modern Europeans.
DNA taken from the tooth of 7,000-year-old La Brana-1 revealed that the ancient individual was a stone-age hunter who possessed dark, African skin, curly brown hair and blue eyes.
Researchers said that La Brana-1 represents the first recovered genome of a European hunter-gatherer, and that his closest modern-day relatives live in Sweden and Finland.
Scientists said the most surprising discovery was that La Brana-1 had a combination of African and European genes. The latest findings suggest that the racial transformation of modern humans was still in progress long after they left Africa and that changes in eye color came before changes in skin color.
"The biggest surprise was to discover that this individual possessed African versions in the genes that determine the light pigmentation of the current Europeans, which indicates that he had dark skin, although we can not know the exact shade," lead researcher Professor Carles Lalueza-Fox, of the Institute of Evolutionary Biology in Barcelona, said in a statement.
"Even more surprising was to find that he possessed the genetic variations that produce blue eyes in current Europeans, resulting in a unique phenotype in a genome that is otherwise clearly northern European," Lalueza-Fox added.
Besides sharing genetic similarities to modern-day Scandinavians, DNA analysis reveals that La Brana-1 also shared a common ancestor with people who lived in Siberia for than 20,000 years ago.
"These data indicate that there is genetic continuity in the populations of central and western Eurasia. In fact, these data are consistent with the archeological remains, as in other excavations in Europe and Russia, including the site of Mal'ta, anthropomorphic figures -called Paleolithic Venus- have been recovered and they are very similar to each other".
Previous theories of Europeans suggest that fair skin evolved as people moved further north to give them the ability to absorb more sunlight to produce vitamin D. However, scientists from the latest study believe that the rise of farming may have been responsible for the lightening of skin tone.
Scientists explained that the Mesolithic period, or Middle Stone Age, lasted from 10,000 to 5,000 years ago. This period, which was between the Paleolithic and before the Neolithic periods, ends with the dawn of agriculture and livestock farming. Post-Mesolithic populations had to evolve genetic traits to survive the metabolic and immunological challenges of the Neolithic period, which was characterized by starchy diets and new bacteria and viruses from domesticated animals.
One of the changes that came in the Neolithic period was the ability for humans to digest lactose. However, DNA analysis reveals that La Brana-1 would have been unable to digest lactose or deal with the carbohydrate-based diet of Neolithic farmers.
The findings revealed that La Brana-1 stood 5.57 feet (1.7 meters) tall and was between 30 and 35 when he died.
"Before we started this work, I had some ideas of what we were going to find," Lalueza-Fox said, according to Forbes. "Most of those ideas turned out to be completely wrong."
"Our results indicate that the adaptive spread of light skin pigmentation alleles (genetic variants) was not complete in some European populations by the Mesolithic, and that the spread of alleles associated with light/blue eye color may have preceded changes in skin pigmentation," researchers wrote in the study.