Chromosome y - DNA and genealogy
Adam and Eve have existed. The Adam Chromosome Y and the Mitochondrial Eve, more precisely. But they have never known each other ... explanations
As a reminder: humans all have 23 pairs of chromosomes including a pair of sex chromosomes. We find the XX pair in women and the XY pair in men. Women transmit an X chromosome to the child, whether a boy or a girl and the man transmits either a chromosome or an X to the child. It is this association that will determine the biological sex of the child.
A woman causing x and y
We are in 1905, in California, Nettie Stevens has just identified the role of chromosomes X and Y and confirms that the sex of the child is determined by these chromosomes. This is the result of several years of genetic research - one of the greatest genetic biological discoveries of the 20th century.
Nettie Stevens was born in 1861 in the Vermont. Very studious and thoughtful, she dedicated to a career in teaching. She will teach English, Latin, mathematics and physiology, among others ... before deciding, at 35, to embark on biology studies. Nettie Stevens decides to specialize in the study of cells with a doctorate in cytology (*cyto: Greek kutos [cyto-, -cyte, -cytie], cell; * Logie, logist: Greek logos[log(o)-, -logie, -logique, -logiste, -logue] science, discours, raison) en Pennsylvania. There, she will carry out all her research on the cells isolated from their fabric, research carried out on various insects (termites, locusts, cockroaches, etc.). It is by studying the larva of a beetle that Nettie will discovery concerning the existence of two chromosomes, X and Y, in the definition of gender.
This discovery will not be recognized by his peers who thought at the time that sex was determined by the mother and other environmental factors. It goes without saying that the place of scientific women, who are more successful, was far from the spotlight. Nettie died 7 years later, in 1912, from breast cancer. This is his thesis director, Thomas Hunt Morgan, a large geneticist, who will then obtain the Nobel Prize for Medicine (in its place, without crediting it) in 1933.
Adam has existed ...
And yes, as we told you a little higher, Adam existed. It is even better known as "Adam Chromosome Y" or "Genetic Adam". This being is, in fact, the ancestor online agnatic (parentage by males, from father to son) of the largest number of living people at present. He left his chromosome to the vast majority of men today. Since 2013, various sources say that the ancestor of humanity has been found up to several hundred thousand years. Some claim that this "genetic adam" is Gengis Kahn (and that he would have transmitted his chromosome there to nearly 16 million men), while others think rather of Giocangga, ancestor of the Chinese imperial dynasty. Finally, the latest "Adam" dated would be African and would have more than 348,000 years.
Crazy, right?
... and Eve too
To perfect the myth, it goes without saying that Eve has also existed. However, it is not the X chromosomes that allow you to go back to it, but its mitochondria (des organites que l’on retrouve dans nos cellules et qui ont leur propre ADN). Celles-ci se transmettent uniquement de la mère à l’enfant. L’homme ne transmettant pas ses mitochondria à ses enfants (car la transmission se fait via les ovules), c’est la suite de la transmission de mères en filles qui permet de remonter jusqu’à notre « Eve mitochondriale » ou « Eve génétique ». Les études de l’ADN et des fossiles démontrent, à l’heure actuelle, que notre « mère commune » viendrait d’Afrique et aurait vécue il a plus de 100 000 ans.
Although both bear the name of the first biblical couple, our Adam and Evene ADAM would never have met. They certainly even lived very distant geographically from each other, some even think of different eras ...
Sachez que vous pouvez vous aussi devenir le futur Adam ou la futur Eve. Il suffit que vous ayez de nombreux garçons – ou filles, et qu’eux même transmettent leur chromosome Y ou mitochondria de manière ininterrompue, pour ainsi faire de vous l’ancêtre commun de la majorité des futurs contemporains. Alors… au boulot !