Who are our closest kin in Europe? We see signs here of the Celtic tradition but did any Celts actually reach our shores in ancient times? How closely related genetically are the two traditions in the North?
These are just a few of the complex questions that could be answered following the announcement today of four research projects which will examine the genetic origins of the peoples of Ireland.
The four were selected from a larger group of applicants in a programme overseen by the Royal Irish Academy and funded by the National Millennium Committee. Each £40,000 project will receive half its funding from the committee and researchers are expected to report preliminary findings this December at a conference organised by the RIA.
The funding, as with all RIA undertakings, was available to groups North and South. The successful research groups are from Trinity College Dublin, University College Cork, Queens University with the City Hospital Belfast and the Royal College of Surgeons with the Children's Hospital.
One might assume that learning about our past would require an extensive root through collections of bones from the National Museum, but in fact only one of the four projects will be attempting to extract old genetic material "ancient DNA" from archaeological remains, explained Trinity's project leader, Prof Dan Bradley.
Most of the detective work, he said, focuses on where we are now and the relatedness that can be established between existing Irish and European populations. A better understanding of our genetic make-up today tells the researchers what to look for in ancient DNA.
But why look back at all? Is it a matter of supreme noseyness for scientists to attempt to genetically brand people? Anything but, explained Prof Alun Evans, who will lead the project at Queens in co-operation with Dr Derek Middleton of City Hospital Belfast. Their project will study differences and similarities between the two populations in the North. The groups clearly have a different historical background but their genes may show they have a greater relatedness than might be assumed.
"It is basically trying to sort out the ebb and flow of human populations and where the earliest inhabitants came from," Prof Evans explained. Archaeologists have found stone carvings characteristic of the Celts in this country, but did they actually colonise Ireland, he asks. "Really the only way to sort this thing out is genetic anthropology."
No assumptions could be made about such things, he suggested. It was known for example that what is now England was colonised about 70,000 years ago but this initial population died out. "Eight to nine thousand years ago modern man came to Ireland, largely bypassing England, Wales and Scotland and inhabiting Ireland. We don't know where those people came from, or where are our natural cousins in Europe."
The work isn't just about locating long-lost cousins. The findings could benefit us in a number of ways, explained Prof David McConnell, professor of genetics at Trinity and also chair of the RIA's advisory committee on genetic anthropology.
The Irish data will fill in part of the wider picture of European migration and colonisation by early humans after the end of the last Ice Age 13,000 years ago. The results could help to explain the pattern of health and illness of the present peoples of Ireland and the excesses we have in certain genetic disorders such as spinabifida.
The Queens/City Hospital project will involve the study of thousands of DNA samples from across the North, looking for specific DNA sequences that will provide information about relatedness between the two communities. Data will be analysed according to surname, what county a person comes from, whether east or west of the Bann, rural versus urban and so forth.
Prof Bradley's project at the department of genetics at Trinity will expand on earlier work looking at current Irish populations and genetic differences between them. He will look in particular at the apparent lack of genetic diversity within the island, which could be the combined result of an initial "founder effect" plus a comparative lack of secondary inward migration.
Dr Barra O Donnabhain will lead a group at University College Cork which includes Benedict Hallgrimsson, Shelley Saunders and Dongya Yang. They are looking for signs of Norse-Irish interactions in the early historic period in the genetic context. The fourth project involves the Royal College of Surgeons with the Children's Hospital and researchers Dr David Croke, Dr Charles O'Neill and Dr Philip Mayne. They too will build on extensive existing research which looks at the presence of specific genetic markers, data which can be compared with matching European data, thus helping to understand relatedness between European populations.