6.7 million to one: the weight of evidence that the Leicester skeleton is Richard III, says lead DNA researcher

There is “overwhelming” evidence that the skeleton discovered underneath a Leicester car park is that of Richard III, expert Dr Turi King has told History Extra

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Just 24 hours before the reinterment of the former monarch at Leicester Cathedral, King, who led the DNA analysis of the Greyfriars skeleton, said those who doubt its identity wrongly “take pieces of evidence out of context”.

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Speaking to History Extra in Leicester, next door to the cathedral where thousands of people queued to see Richard III’s coffin, King said: “It can be rather frustrating because often the people [who question whether the remains are those of the Plantagenet king] aren’t experts in genetics or radiocarbon dating or statistics. What I always say to these people is ‘go and read the supplementary information of our research paper’, because we really did write everything out. We were very specific about what we did and how we came to our conclusions. Please, as in a forensics case, take all the evidence together.”

Explaining the Leicester team’s approach, King said: “It’s like a missing persons case: Richard III, missing, last seen in the choir of the Church of the Greyfriars. What are we looking for? We know he’s 32 years old when he’s killed at the battle of Bosworth in 1485, and that he’s described in near-contemporary sources as having one shoulder higher than the other.

“So we do the excavation, and we find a youngish male with multiple battle injuries and severe scoliosis of the spine. Then the radiocarbon dating comes back right, and the stable isotope analysis fits with his diet and what we know about where he lived when he was growing up. And then you have this genetic match with the female-line relative.

“You don’t have one with the male line, but we have to bear in mind false paternity rates [whereby the recorded father of a child is not the real father] – there’s about one to two per cent per generation. So what you can then do is what’s known as a Bayesian statistical analysis [a subset of the field of statistics in which evidence is expressed in terms of degrees of belief or ‘Bayesian probabilities’]. You bring all of the strands of evidence together and you ask ‘how likely is it to find somebody just randomly who fits all of these criteria?’

“So, ‘what are the chances of finding a male buried in a high status part of a church, and who is the right age?’ That’s one in five. Next, ‘what are the chances of finding someone who has battle injuries?’ That’s one in 42. Then ‘how often do you find somebody who has a condition that might make one shoulder higher than the other?’ That’s one in 212.

“You basically multiply all the probabilities together [along with others not detailed here], and what you come up with is a weight of evidence that these are the remains of Richard III – that’s 6.7 million to one. You can then translate that into a probability.”

King continued: “We were extremely conservative with all our calculations – you’re always trying to play devil’s advocate. And when we do that, we still come up with a figure of 99.99 per cent. To be precise, it’s 99.99999 per cent. So the evidence really is overwhelming that these are the remains of Richard III.

“I know there’s been a lot of stuff in the press [last week Dominic Selwood, writing for the Telegraph, suggested the ‘wrong body’ was being buried in Leicester, and last year Prof Michael Hicks argued that archaeologists ‘cannot say with any confidence’ that the bones are those of Richard III], but what these people do is they take a piece of evidence out of context. You wouldn’t do that in a forensic case – you would look at all of the strands of evidence together.”

King went on: “I know some people say ‘well how do we know the skeleton isn’t just a female-line relative of Richard?’. [Because mitochondrial DNA is traced through the maternal line from mother to child, and does not change over time. Over generations and centuries, this, says Dominic Selwood, ‘means a large group of people in different places with different surnames’. Similarly, Michael Hicks says ‘the DNA match from the Leicester skeleton could equally be the result of the bones being those of someone descended in the female line from Richard’s mother, Cecily Neville, including her two daughters’.]

“What Kevin [Schürer, the genealogy expert behind the search for Richard III] did was he looked back at seven generations and tried to trace males who might have the same mitochondrial DNA type. There was one man who did – a knight of the order of St John’s – but there’s no record of him dying in this country. We think he may have died in Rhodes. He’s the only person who we think could have been of about the right age [to fit the profile], but he doesn’t fit any of the other criteria – we don’t know that he’s buried in the priory of the Church of the Greyfriars, or that he had scoliosis and battle injuries. So again this brings us back to the importance of not taking evidence out of context.”

King also responded to a second issue raised by those who doubt the identity of the remains, concerning the Y-chromosome DNA, which passes from father to son: Selwood wrote in the Telegraph that “Unfortunately, the Leicester car park bones do not have Richard’s expected male-line DNA. This means either the skeleton is not Richard, or that the Plantagenet line has, at an unknown date, been broken by illegitimacy. This male-line DNA is therefore worthless, as it does not prove one way or another whether the skeleton is Richard.”

In reply, King said: “That is factored into our analysis. You also have to remember there is a one to two per cent probability of having a false paternity at any point in that tree. You build all this into your analysis – you don’t discount any evidence.

“The other thing to point out is that our research has been peer reviewed by experts. So we’re not randomly saying ‘this is Richard’ – it has gone through the peer review process.”

Reflecting on the project’s success, King said: “When Richard Buckley [lead archaeologist] emailed me back in 2011 to say he was organising an excavation of a well-known individual, and I quickly worked out it was Richard III, he told me ‘don’t worry, we’ll never find him. It will take up half a day of your time’. Yet here we are, three years later!

“It’s been an incredibly intense project. I’ve had about three weeks off in three years, and weekends have been non-existent! But I’m incredibly lucky.”
 

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To read what it was like to see Richard III’s coffin, click here. You can also read the social media reaction to the reinterment here