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Adam and Eve did indeed exist. The Y Chromosome Adam and the Mitochondrial Eve, to be precise. But they never actually met... Explanations
For reference: humans all have 23 pairs of chromosomes, including one pair of sex chromosomes. We find the XX pair in women and the XY pair in men. Women pass on an X chromosome to the child, whether it's a boy or a girl, and the man passes on either a Y chromosome or an X chromosome. This combination determines the child's biological sex.
We are in 1905, in California, Nettie Stevens has just identified the role of X and Y chromosomes and confirms that the child's sex 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 reflective, she dedicated herself to a career in teaching. She taught English, Latin, mathematics, and physiology, among others... before deciding, at age 35, to pursue studies in biology. Nettie Stevens decided to specialize in the study of cells with a doctorate in cytology (*cyto: from Greek kutos [cyto-, -cyte, -cytie], cell; * logie, logist: from Greek logos[log(o)-, -logy, -logic, -logist, -logue] science, discourse, reason) in Pennsylvania. There, she conducted all her research on cells isolated from their tissue, research conducted on various insects (termites, grasshoppers, cockroaches...). It was actually while studying the larva of a beetle that Nettie made her discovery about the existence of two chromosomes, X and Y, in the definition of gender.
This discovery was not recognized by her 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 women scientists, who succeeded at that, was far from the spotlight. Nettie died 7 years later, in 1912, of breast cancer. It was her thesis advisor, Thomas Hunt Morgan, a great geneticist, who then won the Nobel Prize in medicine (in his place, without crediting her) in 1933.
Yes, as we mentioned earlier, Adam did exist. He is even better known as the "Y Chromosome Adam" or "Genetic Adam." This being is, in fact, the most recent common ancestor in the male line (paternal lineage, from father to son) of the largest number of people living today. He left his Y chromosome to the vast majority of men today. Since 2013, various sources claim that the ancestor of humanity has been found by going back several hundred thousand years. Some claim that this "Genetic Adam" is Genghis Khan (and that he passed his Y chromosome to nearly 16 million men), while others think rather of Giocangga, ancestor of the Chinese imperial dynasty. Finally, the latest "Adam" would be African and over 348,000 years old.
Crazy, right?
To complete the myth, it goes without saying that Eve also existed. It is not the X chromosomes that allow us to trace back to her, but her mitochondria (organelles that we find in our cells and that have their own DNA). These are passed down solely from mother to child. Men do not pass their mitochondria to their children (since transmission is through eggs), it is the succession of transmission from mothers to daughters that allows us to trace back to our "Mitochondrial Eve" or "Genetic Eve." Studies of DNA and fossils show, at present, that our "common mother" comes from Africa and lived more than 100,000 years ago.
Although both are named after the first biblical couple, our genetic Adam and Eve never met. They even certainly lived very geographically distant from each other, some even think at different times...
Know that you can also become the future Adam or Eve. All you need is to have many sons – or daughters, and for them to also pass on their Y chromosome or mitochondria uninterrupted, thus making you the common ancestor of the majority of future contemporaries. So... get to work!