ISSUE395|COMPUTER SHOPPER|JANUARY2021 83
Identificationinvolvedtwoindependentstrandsofresearch.
First,DrKingattemptedtoextractandsequencemtDNAfrom
theskeletalremains(seetheDNASequencingboxopposite).
Meanwhile,ProfessorKevinSchürer,Pro-Vice-Chancelloratthe
University of Leicester,undertookagenealogical investigation.
Professor Schürer confirmed not one but two direct descendants
of Richard’s sister,Anne of York. One was aCanadian-born
furniture maker,MichaelIbsen, and the second wished to remain
anonymous but still provided aDNA sample.The discovery of a
second descendent was particularly important as it allowed the
results to be ‘triangulated’,asDrKing put it. In other words,
while there is asmall possibility that two people share the same
mtDNA purely by chance,the probability of achance match with
two individuals would be very much smaller.
The result is now well known. The researchers were able to
extract sufficient mtDNA from the skeleton to permit an analysis.
The ancient mtDNA was agood match forthat taken from
Michael Ibsen, and also matched the DNA from the anonymous
second direct descendant. However,given that two unrelated
people can share the same mtDNA, how much relevance can we
place on these matches? We asked Dr King forsome statistics
but she didn’t want to give toomuch awaybefore an academic
paper is published. “I can’t discuss that until the paper I’m afraid,”
she says, “but it’s influenced by theamount of sequence I
retrieved, how closely the sequence matches, taking intoaccount
mutation rates, the number of generations and how common
the sequence is in the population.”
MICRO-CT INVESTIGATIONS
The researchers used micro-CT imaging to investigatethe
skeleton in considerable detail. In some ways this is similar to the
CATscanning used in medicine but the image resolution is much
greater.The technique involves beaming an X-rayatthe specimen
and recording the signal at the other side using an X-raydetector.
This is much the same as conventional X-rayimaging using a
digital detector,and the result is atwo-dimensional image in
which each pixel has contributions from every point through
which the beam passed. However,the purpose of micro-CT
imaging is to generateathree-dimensional image,sothe
specimen is rotated and the process repeated until several
hundred to afew thousand images have been obtained.
Then, using atechnique known as filtered back projection,
software is able to calculatethe density of every point in
three-dimensional space and build up a3Dimage that can
be viewed and manipulated onscreen.
To the untrained eye, the micro-CT scan of the skull looks
much the same as athree-dimensional model that could have
been created from aseries of black and whitephotographs using
pattern matching software.But according to Professor Sarah
Hainsworth of the University of Leicester’s Department of
Engineering, micro-CT provides 3D information that allows a
better reconstruction than simple photographs. To illustratethis,
Professor Hainsworth refers to an injury on the skull labelled Bin
the photograph (bottom-left). “The micro-CT allowed us to see
the 3D data through the skull in away that it is difficulttosee in
just photographs,”she says. “For example,wecan see that the
sword that created one particular injury penetrated through the
skull and damaged the inner table of the skull.”
Professor Hainsworth also lists several other injuries to
the skeleton that were revealed by micro-CT imaging. These
include asharp force injury to the rib,which was probably
caused by aknifeordagger,two similar wounds to the right
jaw,two shaving-type injuries to the skull caused by asharp⬆Micro-CT scanning allowed researchers to see the wounds that
probably killed Richard III at Bosworth Field
⬆Micro-CT scanning uses thousands of X-rayimages to createa3D
image of askull in unprecedented detail⬆DrTuriKingatworkinthecleanroomfacilitiesoftheUniversityof
York’sAncientDNALaboratoryProfessorHainsworth listsseveralinjuriestotheskeleton,including asharp forceinjurytothe
rib,probablycaused byadagger