A new analysis by researchers at the University of Finland has detailed how Finnish genetics have changed throughout the 20th century.
A genetic ancestry profile of an individual reveals which proportion of their genome originates from each of the available reference populations. These profiles offer a unique view into an individual’s personal history and is crucial in emerging personalised genomic medicine and also in forensic genetics.
To date, most studies consider genetic ancestry on a broad continental level, for example, in Europe. There is, however, less understanding of how more detailed genetic ancestry profiles can be generated and how accurate and reliable they are. With the increasing interest of direct-to-consumer testing, this research team wanted to take a more detailed look at genetic ancestry profiles.
In their study, published in PLOS Genetics, the team developed a framework for individual-level ancestry estimates within Finland. They applied the framework to track changes in the fine-scale genetic structure throughout the 20th century. In addition, they estimated the genetic ancestry of 18,463 Finnish individuals, tracking their genetics back to 10 distinct, original populations. Harnessing this information, the team then looked at how the country’s genetics changed each year between 1923 and 1987 in 12 geographical regions.
They detected major changes after a sudden, internal migration related to World War II when Finland lost parts of its eastern territories to the Soviet Union. During this time, 11% of the country’s population was forced to move. Moreover, starting in the 1950s, urbanisation left its mark, as people moved into cities in the southern and western parts of the country. The team showed that while the level of genetic heterogeneity generally increased towards present day, the rate of change was considerably different between geographical regions.
This is the first study that estimates annual changes in the fine-scale ancestry profiles within a relatively homogenous European country. It highlights how such information can capture a detailed spatial and temporal history of a population. The team have made their results accessible to the public through an interactive website: https://geneviz.aalto.fi/genetic_ancestry_finland/.
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