LONDON — Leicester, the university that led the effort to identify the remains of English King Richard III, is an appropriate institution to carry out such a remarkable piece of DNA investigation. Its genetics department was the birthplace of “DNA fingerprinting” in 1984, when Professor Alec Jeffeys discovered how to identify people by amplifying tiny amounts of DNA from crime scenes.
For the Richard III project, the Leicester team also brought in two universities, York in England and Paul Sabatier in Toulouse, France, that have particular expertise in extracting and amplifying “ancient DNA” from archaeological sites.
DNA is remarkably resistant to degradation and can survive under reasonable conditions for centuries or even millennia when other biological molecules have decayed away. Its resilience was demonstrated recently by the identification of a new human species, Denisovan man, from traces of DNA extracted from a 50,000-year-old finger bone in a Siberian cave.
The presumed skeleton of Richard III provided enough surviving DNA for analysis from teeth and a thigh bone.
To prove his identify, the researchers used DNA from mitochondria, the biochemical power packs that provide cells with their energy. Unlike the main genome from the nucleus, which is mixed up when sperm fertilize eggs, mitochondrial DNA passes without combination from mother to child.
So the team needed to find people who were descended through the maternal line from Cecily Duchess of York, Richard III’s mother. Historical research confirmed the validity of two such descendants. One wishes to remain anonymous. The other, a furniture maker named Michael Ibsen, is Cecily’s great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-grandson – through 17 female generations.
Both descendants share the same mitochondrial DNA profile as material extracted from the Leicester skeleton. This DNA matching enabled Richard Buckley, the lead archaeologist, to declare: “Beyond reasonable doubt it’s Richard.” But there was also plenty of non-genetic evidence to support the identification.
Radiocarbon dating confirmed that the individual lived in the late 15th century. Mass spectrometry of his bones showed that he had a high-protein diet, including a lot of seafood, as would be expected for medieval royalty.
The skeleton came from a rather slender man in his late 20s or early 30s. (Richard was 32 when he died). From the length of the thigh bone, the scientists calculate that Richard would have stood about 5 feet, 8 inches) tall if his back had been straight. But severe curvature of the spine would have reduced his apparent height, making him look shorter than the average man in the medieval period. These features are consistent with contemporary accounts of his appearance.
Finally, the skeleton showed multiple injuries consistent with Richard’s death in battle at Bosworth Field on Aug. 22, 1485.
— Financial Times