Identical twins look so alike, that, unless you know them very well, it is very hard to distinguish them from each other. Since identical twins have received exactly the same sets of genes from both their parents, that tells us that facial features are almost completely determined by our genetic make up.
The work builds on a project begun in 2004, funded by the Wellcome Trust, to collect blood samples from more than 4,000 people in rural populations throughout the British Isles. How the scientists have used the DNA from these samples to create a genetic map of the British Isles and relate that to the origins of the British population as suggested by archaeological and historical studies, is also a feature of the exhibition.
The exhibit will provide an opportunity for the public to find out about genetics and genetic variation, and how this variation can be used both to tell us about our origins and about the genetics underlying facial features, as well as other normal variation, such as in taste or smell.
Further funding from the Wellcome Trust has enabled Sir Walter Bodmer and his colleagues from the University of Oxford to return to the initial volunteers and collect high–resolution digital 3D photographs of their faces. This makes it possible to measure accurately particular features of a face, such as the size of the nose or mouth. Associations between the variations in these features and the DNA variation from the samples that have already been collected can then be used to find the genetic variations that determine the facial features. This is investigated with Professor Josef Kittler and his colleagues from the University of Surrey.
One of the lead scientists on the exhibit, Sir Walter Bodmer, says:
“Everyone is interested in faces and why little Johnny has a mouth like his mother or a nose just like his father. We aim to find the genetic differences that explain that. Most people are also aware that people from different countries, even within Europe, seem often to have facial features characteristic of where they come from. This suggests that the gene variants that determine facial features may be distributed differently in different countries, and perhaps even areas within a country, such as within the UK .We should be able to explain that too. Facial recognition, which enables us to recognise our kith and kin, has been very important in our evolution and we believe that unravelling the basis for that is a fascinating problem.”
Professor Josef Kittler, the lead investigator for the analysis of facial features:
“We measure the shape of facial features (nose, eyes) in 3D photographs of a large population of subjects and look for individuals at the extreme ranges, with a view to pinpointing those individuals with the largest genetic differences.”
Another lead on the project, Professor Peter Donnelly, adds:
“Your DNA differs from that of your neighbour. These genetic differences, known as genetic variation, are important to understand as they can contribute to inherited differences in susceptibility to, and can help us understand, many common diseases, such as cancer and heart disease. But they also determine many of the outward normal features, such as the face, by which we recognize each other.
We first set out to map genetic variation across the UK. Our results show striking patterns of genetic clustering within different geographical regions of the UK. By comparing the different UK clusters with potential source populations from Europe we are able to learn more about the history of the people of the British Isles.
This new study could be equally interesting, allowing us to connect genetic variation to particular facial features and other normal traits such as skin, hair and eye colour.”
Visitors to the exhibition will be able to see a genetic map of the British Isles created in the first phase of the research and see how the map relates to the known archaeology and history of the country.
They will also learn how family names may provide indicators as to where in the country we come from.
The exhibition opens to the public on Tuesday 3 July 2012. Further details about this and other exhibits can be found here: