Haplogroups in the Crabtree Project
Each of us has a haplotype which is identified, directly or indirectly, as a result of our Y-chromosome and/or autosomal test. This haplotype, or complete set of alleles, provides a pointer to our ancient origin which is measured in geological time. A haplogoup is a cluster of similar haplotypes.
During the Palaeolithic period 18,000 years ago, Europe was in the grip of the last ice age. Glacial ice 2km thick covered much of Northern Europe and the Alps. Sea levels were approximately 125m lower than today and the coastline differed from the present day - for example, Britain and Ireland were connected to continental Europe.
Neanderthals died out around 14,000 years ago leaving the nomadic
hunter-gatherer Cro-Magnon (modern man) to pursue the animals of the time. Due to the cold, the arid conditions and the resultant
scarcity of food, the populations of the day in Europe were concentrated in
three areas in which they waited for the departure of the ice age. These were the Iberian Peninsula, the Balkans
and the Ukraine.
Coming forward 2,000 years, the ice had retreated and the land became much more supportive to life. Many animal species returned to inhabit the land. The land bridges re-flooded, England and Ireland were again separated from Europe. People started to move north again to inhabit new lands where food was available.
However, by the time migration was able to occur, the three groups of humans in Spain, the Balkans and the Ukraine had been both static and separated from one another for so long that their DNA had naturally picked up mutations. The mutations can now be defined into different haplogroups, known as R1b, I and R1a.
- Haplogroup R1b is common on the western Atlantic coast as far as Scotland.
- Haplogroup I is common across central Europe and up into Scandinavia.
- Haplogroup R1a is common in eastern Europe and has also spread into central Asia and as far as India and Pakistan.
These three major haplogroups account for approx 80% of Europe's present-day population.
In the Crabtree project, the members almost entirely fall within two haplogroups:
The maps below show the general movement patterns of these groups, and the more specific migration patterns of the two groups relating to Crabtrees.
General Movement Patterns
Movement Patterns of the I haplogroup
Haplogroup I1 is the most common type of haplogroup I in northern Europe. It is found mostly in Scandinavia and Finland, where it typically represents over 35% of the Y chromosomes. Associated with the Norse ethnicity, I1 is found in all places invaded by ancient Germanic tribes and the Vikings. After the core of ancient Germanic civilization in Scandinavia, the highest frequencies of I1 are observed in other Germanic-speaking regions, such as Germany, Austria, the Low Countries, England and the Scottish Lowlands, which all have between 10% and 20% of I1 lineages.
Movement Patterns of the R1b Haplogroup
European R1b is dominated by R-M269.
The frequency is about 92% in Wales, 82% in Ireland, 70% in Scotland, 68% in Spain, 60% in France (76% in Normandy), about 60% in Portugal, 53% in Italy, 45% in Eastern England, 50% in Germany, 50% in the Netherlands, 42% in Iceland, and 43% in Denmark. It is as high as 95% in parts of Ireland. It is also found in some areas of North Africa, where its frequency peaks at 10% in some parts of Algeria.
It has been found at generally low frequencies throughout central Eurasia, but with relatively high frequency among the Bashkirs of the Perm region (84.0%) and Baymaksky District (81.0%). This marker is present in China and India at frequencies of less than 1%.
Where the link in the Crabtree surname in the two haplogroups, I and R1b, occurred has not been established. Based on the research of extant documents done by many of the Project members with y-DNA results in both haplogroups, it appears fairly certain that all Crabtrees who have now settled in various parts of the world migrated from England at some time since the early sixteenth century. It is also apparent that some of the members originated from the Spanish migration through France to England, and others from the Balkan migration through Germany to Scandinavia, and hence to England.
The above information is abbreviated from the DNA Heritage Masterclass website where it may be read in its entirety – see www.dnaheritage.com → masterclass → haplogroups. The remainder of the information is extracted from Wikipedia under the respective haplogroup titles.