After centuries, it seems, the once-lost body of King Richard III of England has been identified. At a news conference Monday, a team from the University of Leicester reported that a skeleton unearthed last fall was "beyond reasonable doubt" that of the last Plantagenet monarch, who died in 1485 during the Battle of Bosworth Field.
Citing DNA evidence collected from the remains, the team reported that some of the skeleton's genetic information matched that of two living relatives of the king.
Although DNA is often imagined to be incontrovertible proof of identity, in the case of Richard III it's just one piece of information that supports a broader set of proof collected from analysis of the bones, including evidence of scoliosis in the spine (Richard was hunchbacked), radiocarbon dating indicating a date of death consistent with Richard's, and signs of a seafood-rich diet consistent with eating habits of royalty at the time.
The DNA used to identify Richard's remains was mitochondrial DNA, stored in mitochondria -- the tiny powerhouses where energy is made in cells. Mitochondrial DNA is passed down directly from mother to child and mutates very, very slowly over time. For this reason, Nelson said, scientists have been able to use it to look far back into human history, revealing migration patterns and the like. (Another reason human geneticists like studying mitochondrial DNA, he added: It is also far more abundant in human cells than nuclear DNA is, and thus easier to recover from degraded ancient remains.)
In Richard III's case, geneticists were able to examine the mitrochondrial DNA of two living people who were known to have descended, through their mothers' mothers, from the king's sister Anne. After showing that the two individuals shared a "relatively rare" pattern in their mitochondrial DNA, the team recovered mitochondrial DNA from the excavated bones and showed that the skeleton's owner, too, shared that DNA sequence.
That is consistent with the skeleton being Richard III's. "If they don't match, it's not Richard," Nelson said.
But because over centuries thousands of people could descend from one woman and share the same mitochondrial DNA, the other details in this case are also key, he said.
"This one's particularly interesting because there's such good archaeological evidence from the condition of the skeleton," said American Society of Human Genetics director of education Michael Dougherty. "It all comes together as a nice complete story."
In coming months, the University of Leicester team said it will attempt to analyze the skeleton's Y-chromosome -- passed down from fathers to sons -- in a similar manner. The team said it already has identified a "consensus Y-chromosome type" in living descendants of King Edward III, who would have the same Y-chromosome as Richard.