Scientist reveals how Neanderthals from a Croatian cave live on in people today

A Croatian scientist working in Germany is helping uncover how Neanderthals from a cave in northern Croatia contributed to the genetic make-up of modern humans, with inherited DNA linked to both health benefits and increased disease risks.

Croatian scientist Dr Mateja Hajdinjak is leading research into the genetic history of extinct human groups at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

Her work has helped shed light on the relationship between Neanderthals and modern humans, including the legacy of individuals who lived approximately 38,000 years ago in Vindija Cave in Croatia’s Hrvatsko Zagorje region, 24sata reported.

Hajdinjak, a molecular biologist who studied at the University of Zagreb before completing her doctorate at the Max Planck Institute, was part of the team that sequenced and analysed a high-quality Neanderthal genome from Vindija in 2017, alongside colleague Petra Korlević.

The research was conducted in collaboration with Croatian scientists working on the cave and its archaeological remains.

A study published in Nature this year found that Neanderthals from Vindija were genetically closest to the Neanderthal population that interbred with the ancestors of early modern humans. Their genetic legacy can therefore be traced in people living today.

Hajdinjak said her team was preparing further research based on the genomes of 12 Neanderthals from Vindija. The individuals include several biological relatives, such as a mother and daughter, two sisters, and an aunt and niece.

The research could provide additional insight into Neanderthal family relationships, population structure and interactions with early modern humans.

Neanderthal DNA remains present in the genomes of many people today. These inherited genetic variants can influence a range of biological characteristics, including susceptibility to certain diseases.

Hajdinjak highlighted the contrasting effects of different Neanderthal genetic variants associated with Covid-19.

Variants on chromosome 3 have been linked to an increased risk of severe Covid-19, including hospitalisation and the need for respiratory support. In contrast, a Neanderthal-derived variant on chromosome 12 has been associated with protection against severe disease.

Other inherited variants have been linked to type 2 diabetes. Hajdinjak noted that some genetic changes associated with health problems today may once have provided an advantage during periods of food scarcity.

The effects of inherited DNA depend on the particular variant and the environment in which it operates.

Why did Neanderthals disappear?

The reasons Neanderthals and other archaic human groups disappeared remain uncertain.

Researchers have proposed several explanations, including competition for resources, differences in population size, environmental adaptation, disease and the absorption of smaller populations through interbreeding with modern humans.

Hajdinjak said the evidence does not clearly establish one explanation as superior to the others. A combination of factors is likely to have contributed.

Modern humans emerged in Africa at least 300,000 years ago. Genetic evidence indicates that the ancestors of modern humans, Neanderthals and Denisovans diverged hundreds of thousands of years ago, while later encounters led to further interbreeding.

Although Neanderthals and Denisovans no longer exist as distinct living populations, traces of their DNA remain in modern human genomes.

Research involving Vindija Cave continues to provide important evidence about these encounters and the evolutionary history shared by modern humans and their extinct relatives.