For the University of Leicester team, however, the nail in the coffin of the identification was a DNA analysis that matched that of Michael Ibsen, a modern-day descendent of Richard III through the maternal line, along with DNA from another descendent on the maternal line who asked to be kept anonymous. The DNA used is mitochondrial DNA, which is contained in the part of the cell that transforms nutrients to energy; this type of DNA is passed down only through the maternal line.
Ancient DNA, however, is very susceptible to contamination, sparking some skepticism.
"Before being convinced of any aDNA study, it should be explicit that all possible cautions were taken to avoid potential contamination," Avila wrote in an email to LiveScience. "It is just part of the protocol." (aDNA refers to ancient DNA.)
Avila also warned that people could share mitochondrial DNA even if they didn't share a family tree. To be confident that Ibsen is related to the owner of the disinterred skeleton, the researchers must present statistics showing how common the DNA profile is in the United Kingdom, she said. Otherwise, the similarities between Ibsen's mitochondrial DNA and the skeleton's could be coincidental.
Avila noted that she doesn't necessarily disbelieve the team's conclusion that the skeleton is Richard III's, just that the DNA evidence isn't the strongest piece of the puzzle.
"It seems to me that osteological as well as archaeological evidence is stronger, however 'DNA evidence' sounds fancier so it looks like they used it as the hook to capture the attention of media," she said.