‘Who we are and where did we come from?’

A talk given by Francis Taylor on 20th January 2024

Today’s talk started with a look at ancient literature to see how people tried to identify their origins. Thus, after the Biblical Flood, one of Noah’s sons, Japhet, was believed to have populated Europe. We learnt that ancient Romans believed that a descendent of Aeneas, Brutus, populated Britain, and named the country after himself. We heard how hair colour, skull shapes and blood groups had been studied in attempts to determine from where people had come.

Then came the discovery of isotopes. From what people had eaten and drunk during their lifetime, scientists were able to tell where they had lived. Thus, isotopes of oxygen and strontium, found in teeth, showed where an individual had lived in their childhood. Isotopes of carbon and nitrogen, found in bone, showed where a person had lived in the last years of their life.              

From isotope studies and where an individual had spent their lifetime, we moved on to ancient DNA studies, and looked at where an individual’s ancestors had come from. A quick revision of genetics reminded us of inheriting 23 chromosomes from our parents, with men getting 22 matched pairs, plus one X and one Y chromosome (which carries maleness, and was inherited only by men from fathers). Also, that Mitochondrial DNA (Mt-DNA), was inherited by both men and women, but only from mothers. 

A diagram of a family tree showed clearly how while sons inherit both Y-DNA and Mt-DNA mutations, they only pass on Y-DNA mutations. However, daughters both inherit and pass on Mt-DNA mutations. Mutations in DNA are what drives evolution, with good mutations resulting in an individual thriving. 99.9% of human DNA is identical, and it is the remaining 0.1% that makes each of us unique. 

From the extraction of ancient DNA (aDNA), often from minute fragments of ancient skeletons, the whole science of tracing ancestors; where we have come from, has arisen. Francis told us about ‘Mitochondrial Eve’, who lived in Africa about 190,000 years ago, and who is thought to be the most recently shared ancestor of modern-day humans along the maternal line.

Mt-DNA mutation markers (haplogroups), are labelled sequentially with letters of the alphabet. The first haplogroup was labelled “L”, rather than “A”, for historical reasons. Thus, ‘Mitochondrial Eve’ had an “L” marker, and while other branches of the “L” marker are found in Africa, the “L3” marker, from which all non-Africans are descended, moved north out of Africa about 60,000 years ago. We looked at a ‘Map of Mitochondrial DNA Migration’ and saw how “L3” had moved out of Africa, with different haplogroups spreading all over the world, and with “H” going to Britain, arriving about 10-1,000 years ago.

We looked at maps showing the interaction of Neanderthals and modern humans, resulting in Neanderthal DNA being found today in all people, except sub-Saharan Africans. We looked at an intricate graph of climate change and ancient visitors to Britain between the Ice Ages, from 1,000,000 years before present, to today, with Homo sapiens the last arrivals, and still here!

Francis told an interesting theory of why Neanderthals died out. Homo sapiens men had bigger, stronger bones than Home sapiens women, and it was thought that men went hunting, bringing home meat for their families, while the women raised children, as well as ‘gathering’ extra food. In this way Homo sapiens thrived. However, both Neanderthal men and women had big, strong bones, and it is thought both hunted. Analysis of Neanderthal bones show women and children suffering from malnutrition. It is thought that without females raising children and gathering supplementary food; crucial if the hunt failed, Neanderthals did not thrive. 

Agriculture had begun by about 9600 BC, and spread from the Fertile Crescent in the Middle East into Europe, with the men carrying the Y-DNA haplogroup G. We heard how Neolithic people were thought to have arrived in Britain from Europe. First, via a possible false start in the west of Ireland, where finds suggest a meal rather than a settlement. Then, via the Irish Sea, with evidence provided by the Pygmy Shrew, found in the Pyrenees and Ireland, but not in the rest of Britain. The next arrivals travelled up the North Sea, settling on the east side of Britain. The last arrival of Neolithic people was across the Channel into southern England.

We looked at a map of Britain showing how very little Mesolithic DNA remains in today’s population compared to Neolithic DNA. The Neolithic men carried the Y-DNA haplogroup G, with the few women who came with them having Mt-DNA markers which are carried by about 8% of modern-day British women. That so few men in Britain today carry Mesolithic Y-DNA suggests that the Neolithic men killed most of the Mesolithic men. 

After the Neolithic came the Copper Age and then the Bronze Age from 2200 BC, with the influx of the Beaker and Corded Ware people, and their steppe ancestry. Yamnaya pastoralists arrived from the steppes about 5000 years ago, resulting, in Britain, with 100% of people having steppe ancestry. We looked at the dramatic change in the DNA of Britons, seeing, this time, the removal of Neolithic men and their Y-DNA haplogroup 12a, leaving mostly men with Beaker Y-DNA haplogroup R1b.

We looked at a ‘Y-DNA Haplogroup R1b migration map’, and saw how this haplogroup had spread from the Middle East, through Europe and into Britain. A ‘family tree’ of the Y-DNA haplogroup R1b showed that the most common sub-groups in Britain are L21 and S21.

A map of the distribution of Y-DNA haplogroup R1b-L21 in Britain and Europe showed how closely the British and Irish are related to their nearest neighbours on the continent; the northern French. A map of the distribution of Y-DNA haplogroup R1b-S21 showed how many Britons are related to Europeans to the east of France, such as Germans and Scandinavians. 

We looked at a map showing the modern distribution of Y-DNA haplogroups in Europe, Britain and Ireland. Colourful pie charts showed the predominance of haplogroup R1b in Britain and Ireland, and in our nearest European neighbours. Noticeably, isolated Ireland had mostly R1b, with just a little I1, 12a and R1a. Britain has more of these, as well as small amounts of three other haplogroups, similar to our continental neighbours.

Looking at Britain by region showed how each area had different amounts of the various Y-DNA haplogroups, showing how individuals had a variety of different ancestors, but with R1b always predominating. A table of ‘Mt-DNA frequency by region’ showed the predominance of haplogroup “H” in Britain, which arrived from Africa, as we heard earlier, about 10-1,000 years ago.

Report by Joan Burrow-Newton

Exploring the archaeology, history and heritage of Berkshire