Discovering your GeoMother™ using mitochondrial DNA Mitochondria are tiny structures found within the cytoplasm of certain types of cell. They contain the enzymes that are necessary for energy production, which is why they are often referred to the “powerhouse” of the cell. They are only passed along by the mother because at fertilisation there is no cytoplasm in the sperm and so no mitochondria are received from the father. Mitochondrial DNA, abbreviated as mtDNA, has its own genome, which is very small – only 16,569 base pairs in length and less than 1/300,000th of the total length of DNA molecules found in the nucleus of a human cell. Nevertheless, mtDNA provides scientists with a very powerful tool for researching ancestral female lineages. This is because unlike with other forms of DNA, the major part of mtDNA does not get changed when it is passed down from mother to child. Occasionally, however, as mtDNA is passed on from one generation to the next, its genetic code does undergo a very small alteration. The vast majority of these alterations are completely harmless and so are eventually passed on to succeeding generations. Over time, further small alterations occur. In this way, separate family lineages become increasingly different from each other. Building a global family tree By comparing two individuals’ mtDNA, it is possible to judge how closely they are related. If their genetic codes are very similar, we can say that they share a common female ancestor in the recent past. The more differences that have accumulated in their genetic codes, the more generations have passed since their last common ancestor. Scientists have used this basic principle to compare the mtDNA from thousands of men and women living all across the planet. They have used their findings to construct a global family tree of female ancestors.

The journeys that shaped history

This female family tree is rooted some 150,000 years ago, at a time when the ancestors of all modern humans were living in Africa. As some of these early groups of humans took their first tentative steps out of our ancient homeland, their journeys led them in different directions and their family lines gradually began to diverge. It is these different lineages that form the separate branches of the global family tree.

GeoGene has divided the female family tree into 24 unique accounts tracing the most important of these journeys – the ones that would define the course of subsequent human history. The account we send you will reveal the route your own maternal ancestors took as they left Africa, explaining how and when your ancestors arrived at the part of the world in which their genetic inheritance is most visible today. You might, for example, learn that you inherited your mtDNA from a woman living in Spain, or Italy, or elsewhere, at the time of the Great Ice Age, who struggled to survive as the glacial sheets overwhelmed the land. Or you might discover that your genetic inheritance comes from one of the very first groups of modern humans to reach Europe, during the period when our Neanderthal cousins still roamed that continent. Or perhaps your genetic code has a different story to tell.

Every human being alive today has a direct connection to one of these epic journeys, but nobody cannot be certain which simply by looking at that person’s physical characteristics or country of birth. Only the latest genetic technology can reveal which of these journeys began your own family’s history.