You may remember Adam and Eve, a nice couple who fell victim to a kind of insurance broker. They had to master life ever after on the verge of bankruptcy and suffered their share of familial problems. Their angel son was murdered by his own evil brother only leaving them with the culprit and Seth, a reincarnation of their dead son.
Have you ever wondered who of the two your ancestor is? Science has the answer, it can trace your ancestors back to the first human beings.
Men have an advantage over women, because the Y-chromosome is being transmitted from father to son and never to the daughters. On the other hand the mitochondrial DNA is only transmitted from the mother, but to all her offspring. Therefore women can only trace their female lineage.
Let’s concentrate on the Y-chromosome only; passing on the chromosome means that this chain of chemicals, figuratively speaking a chain consisting of 120 million beads in four different colours is as old as mankind, never changing, eternal, if it would not be for the odd mishap.
The copying of the chain sometimes leads to the threading of a wrongly coloured bead, which then is being being further multiplied with each copy.
Nobody can predict when a copying error occurs. Kain’s and Seth’s Y-chromosomes may have been identical, but an error certainly occurred in subsequent generations.
The carriers of those changes are categorized into so called haplogroups, which distinguishes them from the others. They define their most ancient shared ancestor and the estimated time the mishap occurred. The twenty most important groups are mainly the most ancient ones and all men belonging to
a haplogroup are required to have the same erroneous bead whereas all the other ones don’t.
Those haplogroups obviously keep branching into subgroups according to the number of further mishaps. It is certain that the haplogroup A never left Africa. The members are not sharing the changes of specific beads of haplogroups B to T and are considered to be the heirs of the so-called Y-chromosomal Adam, the Y-chromosomal DNA of the first human beings.
The changes of the colour of certain beads generating group B happened about 65.000 years ago, when humans left Africa via the Middle East. Haplogroup R is predominant in Europe (60-100% of men), but also in Northern India and North-eastern America. It is believed to exist for about 65.000 years, too. A mishap lower down the line, generating group R-1b, happened around 18.000 years ago in Western Asia, generating nearly
exclusively the European populations.
Not surprisingly further shifts coincide with presumed ancient migrations due to the glacial periods and known early medieval migration routes. A complete chaos is found in ancient coastal areas. Of interest is the I haplogroup, which only features in Scandinavia, the Balcans, Northern Germany and England. This group is the only major haplogroup which originated in Europe itself – natives from the beginning so to speak.
But what does the future hold? Well, the Y-chromosome is a very small chromosome with few genetic tasks. In its opposing X-chromosome it has no near-identical partner and even worse it is fragile. The assumption is that one day it will be lost, the important parts being slowly absorbed by the X-chromosome.
What will then define male? Something will define it, but may be this is still beyond our imagination. Remember, who knew about chromosomes in 1950!