Genetics is the science of genes and genetic variation, and how these are passed on to the next generation.
Each living cell carries the genetic information for the development, function and maintenance of an organism. Most of this information is stored in a biomolecule called Deoxyribonucleic acid (DNA). DNA consists of two polymer strands which form a double helix. The two strands are composed of a large number of nucleotides which differ biochemically. We can distinguish between four different nucleotides (A, C, G and T) and their order along the strand encodes the genetic information. The complete set of DNA in a single cell is called a genome. Most parts of the human genome is identical between two individuals (approximately 99.9% ). The entire genome in a human cell, however, has about 3 billion nucleotides so we still observe about 3 million differences between any two individuals.
Most of our genome is inherited through a complex process of combining the genomes of our parents. There are some parts, however, that are inherited directly from either of the parents. Mitochondrial DNA is directly inherited from the mother while the Y chromosome in males are directly inherited from the father. Consequently, mitochondrial DNA allows to trace the maternal and Y chromosome variation the paternal history. For many decades investigations utilizing these markers were the golden standard and while these studies have had some success, thanks to technological advances, we can now take much more powerful approaches employing partial or complete genomes to infer the demographic history of human populations. This gives us the possibility to look at millions of sites across the genome simultaneously. The higher resolution helps to understand population history in unprecedented depth and it also enables us to assess sex as well as physical appearance of the individuals.
The Atlas project aims at studying the genetic variation that exist between and among prehistoric populations with a primary focus on Scandinavian populations. Obtaining the information from partial or complete genomes from archaeologically well described specimens, we are putting the Neolithic Scandinavians into context with ancient and contemporary humans from different parts of Eurasia. This allows us to genetically characterize these groups and understand their past as well as their connection to modern Scandinavians.