My family tree doubles at every past ancestor generation and continues branching back into the past. At what point does it reduce in size to reflect the size of the population? (continued)
Robert Cy Jones
East Grinstead, West Sussex, UK
This is a complicated answer to a simple question.
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For the UK, the most obvious answer is around the late 1400s. Assuming a generation every 25 years, it’s a simple mathematical progress that arrives at 2,097,152 after 21 generations. From a base year of 2000, this puts us at the year 1475, when the UK’s population was around 2.1 million (still recovering from the Black Death).
However, this assumes that each pair of our ancestors on our tree are all different people. This will not be the case, as, say, your mother’s great × 20 grandparents might, hypothetically, be the same as your father’s great × 21 grandparents.
Your tree will go on accumulating pairs of ancestors, but, gradually, most will all become the same pair.
Confused? As my mother astutely observed, it’s not a family tree, but a forest.
Don Locke
Leamington Spa, Warwickshire, UK
It depends on the individual. Like the rest of us, King Charles has 32 great-great-great-grandparents, but more than you might expect of them are Queen Victoria and Prince Albert.
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