Question: How can you know where your ancestors came from

Paul McKeegan answered on 9 Nov 2017:

Genes!
As humans, we are all very similar in terms of our DNA. But there are still millions of tiny differences. So thanks to the Human Genome Project, we can look at all of the DNA is a person’s cells and can trace these differences through different families, places and ethnic origins. Sometimes there is a fairly obvious genetic difference, with an effect on appearance, digestion, tolerance to altitude, diet or toxins like drugs and sometimes it is a difference with no apparent effect at all. There is a lot of ‘junk’ DNA in our genome which has no apparent role but contains chunks of DNA sequences that are only in folks of Celtic, Norman, Gallic descent etc. Nowadays there are companies which sequence the bits of your genome which contain this information for a fee!