By Jean Christou
IT’S ALREADY a well-known fact that Cypriots have mixed blood due to the island’s geographical location and its history, but a new study has produced some surprising results in terms of how much ‘Cypriot DNA’ has shown up in other populations as far away as Yemen.
Scientists have just published a new ‘genetic atlas’ following their discovery of 95 distinguishable populations around the world. Using this data, a team led by Simon Myers of Oxford University, Garrett Hellenthal of University College London and Daniel Falush of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have been able to isolate different DNA markers that they can ‘cross check’ with other populations.
In this way they have been able locate the markers from other populations present in a person’s DNA, and can also use the information to track some of the historical or migrational events that have resulted in the mixing of DNA among populations. They call it ‘genetic admixture’
Even though all humans have the same set of genes, their genomes contain a number of mutations, which contain patterns passed down from parents to children and makes them common in a particular population. Using these patterns, scientists can scan a person’s genome and assign them an ancestry to a particular population or race. So although Cypriots may have mixed blood, there are markers that make them uniquely Cypriot.
Using this ‘Cypriot DNA’ pattern, the researchers were able to determine, for instance, that Hungarian people, although their DNA contains a majority of Polish and Lithuanian markers, it also contains a substantial amount of Cypriot DNA – almost 20 per cent – in those scanned.
Similarly, Romanian DNA contains mostly Lithuanian DNA, but almost equal amounts of Greek DNA and Cypriot DNA.
The Turkish test subjects were found to have 11 per cent Greek DNA, 9.9 per cent Armenian, 8.5 per cent Iranian, and 6.2 per cent Cypriot.
Other populations where Cypriot markers were found included Armenian 4.8 per cent, Bedouin 7.4 per cent, Belorussian 1.4 per cent, Bulgarian – over 12 per cent – Druze, 11.3 per cent, Egyptian 6.5 per cent, French 6.4 per cent, Iranian 6.3 per cent, Jordanian 9.9 per cent, Syrian 8.8 per cent, Tunisian 5.9 per cent, Italian 7.7 per cent and Yemeni 4.8 per cent.
Armenians were found to have predominantly Iranian, followed by Cypriot and Syrian markers.
Cypriots generally consider themselves to be ‘Greek blooded’, and indeed in the tests done on Cypriots, Greek markers accounted for around 23 per cent of the DNA. But according to the study, there are Greeks out there with Cypriot markers reaching almost 12 per cent. The biggest DNA contributors to the Greek genome, according to the study, were Polish 30 per cent, followed by Italian, Iranian, Jordanian and Syrian.
Apart from ‘Greek DNA’ markers, Cypriots showed signs of Iranian, Italian – a significant 20 per cent – Sicilian, Armenian, Syrian, Georgian, Saudi and Palestinian markers.
For the research, the scientists used 1,490 individuals sampled from the 95 identifiable worldwide groups.
In a Q&A on the ‘genetic atlas’ website they said that most human populations are a product of mixing of genetically distinct groups that interbred within the last 4,000 years.
By using ‘chromosome painting’ the scientists are able to take a string of DNA from the beginning of the chromosome of an individual and colour it according to the world-wide group in the sample that it most closely matches.
“Our approach aims to identify the movements of peoples that resulted in interbreeding or DNA exchange at different periods in human history, and quantify the proportion of DNA transmitted to the present day,” said the researchers.
“Many of the admixture signals we observe do appear to match well, in terms of both times and groups involved, with historical events such as the Arab slave trade in the Mediterranean, the Mongol era expansion and the Slavic/Turkic expansions, and help determine the extent and proportion of DNA contributed by each.”
They said the Mongol expansion seemed, according to both history and genetics, to have been a particularly abrupt transfer of people and DNA across Asia.
Also several groups showed very recent admixture, including the South American Maya, whose signal of mixing between multiple groups agrees with groups and timing for European/ Spanish settlers in the region. The Maya also showed traces of Irish DNA, and the Irish people scanned had significant Greek DNA markers, although their make-up was predominantly Scottish and Norwegian (Celtic and Viking).
Interestingly, the English genome showed no strong evidence of admixture. “This doesn’t mean something didn’t happen but British genetic mixture is generally made up from people of the same part of the world rather than from different genetic groups like we see elsewhere,” Dr Hellenthal told the Independent newspaper. The results show that English DNA comprised 80 per cent Scottish, Welsh and Irish markers, with Welsh being predominant at 41.7 per cent.
The scientists plan to carry out a more indepth study in England titled the ‘Peopling of the British Isles’ using a far greater number of individuals.
The interactive map can be found at: www.admixturemap.paintmychromosomes.com.
