Event Review: Genomics Lite – Ancient DNA, excavating fact from fiction!

As a current student in year 12 in the UK, I felt honoured to be asked to review a webinar aimed at 14 to 16 year olds for BioNews. 'Ancient DNA, excavating fact from fiction!', part of Wellcome Connecting Science's Genomics Lite programme of digital events and live webinars, aimed to explain the different methods of ancient and historical DNA extraction and analysis through age-appropriate explanations and examples.

The webinar began with hosts (Sam Shingles and Jack Monaghan) discussing the differences between ancient DNA and historical DNA. They described the basic outlining factors for why some older DNA samples are so difficult to access. These factors could be biological, chemical or geological and are often linked to changes in temperature over a period of time.

After the brief introduction, Dr Petra Korlevi, staff scientist at the Wellcome Sanger Institute, was introduced. She specialises in the change in mosquitoes since the introduction of insecticides. Dr Korlevi showed an image of the world map with keys showing the temperature in each region and a dot for where ancient DNA samples have been found. I liked this image due its immense simplicity, yet with the ability to show the link between temperature and preservation. The link, I learned, was that the colder the temperature the longer DNA was preserved. This showed the clear difference between the Northern and Southern Hemisphere's temperature, with all but one sample being found in the North. Dr Korlevi explained that this anomalous sample in Africa was found in a cave in a cooler region, hence the long time of preservation.

Following the introduction, Cameron Ferguson, PhD student at University College London, shared his research on pathogens through the changes in DNA from Neolithic times to the modern day, via the Middle Ages. Ferguson then explained that a reason for the difficulty in examining ancient DNA is not only the temperature but, the half-life (512 years). This prevents humans from analysing DNA from millions of years ago as it degrades into matter that is too small.

Ferguson went on to describe the practical side of DNA sampling. This provided a new layer of understanding to the process as he went into detail on how a tooth is drilled in order to reach the section that will be used for analysis. These practical details are often missing from biological presentations so it was interesting and more engaging for me.

Overall, I enjoyed the balance of information provided by each host. This gave me equal knowledge on either host's expertise and also kept me engaged as the narrative would continuously change, maintaining the webinar's engagement for children aged 14 to 16.

Also, the slightly humorous mood created by the hosts throughout made the webinar unique to the target audience and therefore memorable. This was especially relevant for the DNA extraction of the mosquito where a small joke about the difficulty of the process kept the details of the process fresh in my mind.

I also found the process of extracting DNA from the tooth amusing due to the lack of professionalism in the process involved. Ferguson made the process seem simple which is appealing and quite inspiring to the younger audience as these biological processes often come across as too delicate and highly skilled, rendering them unachievable. The speakers also explained how there is not one specific method of extracting DNA and that methods change between different research centres. I found this to be the most interesting part of the webinar as it showed the variation in methods in the same scientific fields. It made me aware that there are no set methods of research which reminded me that science is constantly changing and that methods to reach a conclusion can be different.

To conclude, I found the webinar to be a useful tool for 14- to 16-year-olds and even those in the general public that are interested in genetics. It gave a simple summary on the detail of ancient and historical DNA collection and analysis. It also gave hard-to-access details on the practical side of collecting DNA and the methods used. I believe that this section of the webinar held most of its value due to its uniqueness and precise detail. Even though this section was more of a summary of extraction techniques it gave the reader enough detail to feel as if they have clear enough instruction on how to extract DNA and they therefore see the webinar as a useful and interesting resource rather than a monotonous re-read of previously known information.