Heather Calvert, Marketing Executive at ScotlandsDNA, which can trace British and Irish DNA lines back 3k to 10k years. Humans started in Africa; went to Saudi Arabia; and branched to everywhere else. Each of us inherits 6 B letters of DNA from our parents (3B each).

Occasionally tiny errors of copying are made in reproduction and it is these minute changes that are called “markers”. Geneticists can locate marker’s origin and date its creation. By looking at its frequency in modern populations, they can also track the movement of a marker across the face of the earth. Examples of markers are “Jewish” and “redhead”. For those interested, go to website www.scotlandsdna.com.

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