Paternal DNA Introduction
Genetic research over the last decade has gradually defined the deep-rooted relationships between Ychromosomes from all over the world and what emerges is an evolutionary tree that connects all males on the planet. Rather like the maternal family tree of all humanity, defined by mitochondrial DNA, the paternal tree is composed of clusters of genetically similar Ychromosomes connected together. There are fifteen clusters on the main tree and all trace back to one Y-chromosome, that of 'Y-chromosome Adam', the common paternal ancestor of all living men.
The research that led to the construction of this tree was not based on the genetic marker systems used to construct your Y-Clan TM signature. These markers have a high rate of change to allow for tracing recent, shallow ancestry over a few tens of generations - ideal for genealogy and family history. Instead, the evolutionary tree was built up on a much more stable genetic system based on slow changes, mostly single base mutations known as single nucleotide polymorphisms (SNPs), which have generally occurred only once during the course of human evolution. However, because Y-chromosomes in different clusters are only very distantly related, their Y-Clan TM markers have also differentiated. This means that there is often a correlation between Y-Clan TM signature and clusters on the formal tree defined by the SNP system. From these correlations we are often able to recognize the cluster to which your Y-chromosome belongs based on its Y-Clan TM signature alone. The correlation is not exact, and its reliability differs in different clusters, but it allows us to give you information about your ancient paternal ancestry from your Y-Clan TM signature.
The maternal family tree assigns your mitochondrial DNA analysis result to one of 36 clans, each founded by one woman, whose names appear on our MatriLineTM World Clans certificate. Our YClan TM certificate is drawn along similar lines. The clusters are shown as circles and their relationship to one another indicated by the connecting lines. The gold star indicates our best estimate of your own ancient paternal clan, based on your Y-chromosome signature, which is shown towards the bottom of the chart. By the same logic that traces the maternal ancestry of a clan back to just one woman, the paternal clans were each founded by a single man. However, rather than name the founder himself, we have given the whole clan a name, often chosen from gods or mythological heroes in those parts of the world where the clan is at its strongest. Where possible, we have chosen names which begin with the letter used by the scientific researchers in the Y-chromosome consortium (YCC) to define the clan.
Chromosomes are packets of DNA contained within the nucleus of your body's cells. Most chromosomes come in pairs, with one of each pair being inherited from your father and the other from your mother. However, the Y-chromosome is the exception; only males have one and they inherit it exclusively from their fathers. Something else unusual about the Y-chromosome is that while all the other chromosomes are packed with genes that control the myriad functions of the human body, the Y-chromosomes has only one gene of any real importance - the 'sex-determining' gene. This is the gene that makes males male. Without it, all human embryos would remain as females (the default state) and all babies would be girls.
Males Have Y-Chromosomes
It is because of the sex-determining gene on the Y-chromosome. Half the sperm cells made by men contain a Y-chromosome. An egg fertilized by one of these sperm develops into a male; an egg fertilized by a sperm without a Y -chromosome will develop into a female. It follows that a man inherits his Y-chromosome from his father, who got it from his father, who got it from his father and so on back through time.
There was actually nothing remarkable about any of these clan fathers when they were alive. We know that each one of them must have survived long enough to father children and that each had at least two sons, starting-off expanding lines of descent that reach right down to all of us living today. These were real people, real men who hunted and fought for their families, but who lived in very different circumstances to those that we enjoy today. These really were our true ancestors.