New research into Iceland’s genetic history suggests that its first settlers have greater similarities with the inhabitants of Norway, Britain and Ireland than its own present-day inhabitants.
This is one the main conclusions from a study by the Spanish National Research Council (CSIC) and partners. The researchers analysed the ancient genomes of 27 people who lived in Iceland during its colonisation.
A unique genetic history
Iceland’s first settlers arrived from Norway, Britain and Ireland between 870 and 930 AD. In just over 1,000 years, its population has grown modestly to 330,000. Opportunities to directly study the founding of a human population and its subsequent evolutionary history are rare. With such a small, isolated population with some inbreeding, it is often considered a particularly interesting subject for genetic studies.
CSIC researcher Carles Lalueza-Fox from the Institute of Evolutionary Biology explains: “This work takes an in-depth look at the process which makes small, isolated populations go through random changes in their genetic variability over time. Present-day Icelanders have been affected by 1,100 years of profound genetic drift. This means they are more similar to each other, yet different to modern populations of continental Europe.”
Gender bias in Iceland
deCODE Genetics, a Reykjavik biotechnology firm, contributed seven centuries’ worth of genelogical records to the study. The information confirms a gender bias in the population of Iceland.
“The settlers of Celtic origin had fewer offspring compared with those of Norwegian origin. This is probably because there were more men of Scandinavian origin compared to more women – who would probably have come to the country as slaves and servants – from Scotland and the rest of Britain,” explains Lalueza-Fox.
Sunna Ebeneserdóttir, a researcher from deCODE Genetics, continues: “We have always known that Icelanders descended from Norwegians and Celts, and the analysis of the ancient genomes from the first colonists allows us to see what they were like, both before mixing started, as well as throughout the whole process.”
A medically-significant study
In providing a detailed impression of the origin of Iceland’s human population, the scientists have found a key to making advances in medical treatment. Finding ways to diagnose, treat and even prevent diseases is now within the realms of possibility. For instance, as the study includes the discovery of an ancient person with Klinefelter syndrome, there can now be deeper research into the disease.
“Iceland is big enough for the diseases that affect Europeans to be represented, yet small enough to easily carry out genetic studies which lead to discovering the roots of these complex pathologies. In the not too distant future, we will be able to study the actual individuals who had a certain mutation 1,000 years ago and make a comparison with current patients,” finishes Lalueza-Fox.