The full programme book (PDF) - Royal Geographical Society

THEME 11: INSIGHTS FROM GENETICS
Insights from genetics – the past and future of ancient DNA research
Terry Brown
Manchester Institute of Biotechnology, Faculty of Life Sciences, University of Manchester, Manchester
M1 7DN
It is almost 30 years since the first report of ancient DNA (aDNA) in a quagga skin and 25
years since the discovery of aDNA in preserved bones. During the intervening years,
aDNA research has progressed through an over-ambitious phase during which anything
seemed possible, a re-evaluation phase when nothing seemed possible and everything
appeared to be modern contamination, and finally to a more sober and productive phase
that can be traced back to the early 2000s. The growing maturity of aDNA research has
been driven by an increasing understanding of the technical regimes needed to limit
contamination of ancient samples with modern DNA and to recognize contamination when
in occurs. Today, contamination is still a major issue when human remains are studied,
but is no longer a serious problem with non-human material, at least when the work is
done properly. The current productivity of aDNA research is also due to the introduction of
new ‘next generation’ sequencing (NGS) techniques, which have now largely replaced the
previous methodology based on the polymerase chain reaction (PCR). With PCR it was
only possible to obtain a few short sequences from an aDNA extract, but NGS provides
many millions of sequences in a single experiment. NGS can therefore be used to
sequence the entire genomes of extinct species or of prehistoric examples of extant
species, or can be directed at individual genes and groups of genes of interest.
Metagenome sequencing, in which all the aDNA in an environmental sample such as a
sediment core is studied, is being used to reconstruct palaeoecologies. In many respects,
the limit to the ambition of aDNA researchers lies not with the questions being asked, but
with the bioinformatics challenges inherent in handling and analyzing the millions of
sequences that are now routinely obtained. The future trends are staggering in their
possibilities. Sequencing a modern human genome is now so easy and cheap that it could
be considered for an undergraduate lab class and the techniques that make this possible
are rapidly being superseded by even more powerful ones. In this paper I will attempt to
map out the ways in which this revolution in aDNA research will revolutionize Quaternary
science in coming years.
Keywords: ancient DNA; genetics; genomes; palaeoecology.