Until recently, this appeared to be an implausible science fiction novel. But today you can get data about the likely geographic origin of our ancestors through DNA analysis! We talk about the possibilities of modern genomics from the book “DNA is not a sentence”. This is a real wow! 🙂
Early history of the species Homo sapiens sapiens
How is it possible that DNA contains information about where our ancestors came from? To answer this question, we must first look at the early history of our species Homo sapiens sapiens. The first people of modern anatomy appeared in the savannahs of East Africa about 150 to 200,000 years ago. A more exact dating and the time of subsequent migrations are still being discussed.
People spread across Africa about 50-60,000 years ago. Then a relatively small group decided to leave for reasons that were not fully understood. Immigrants crossed the Suez isthmus and made their way to the Middle East. Some of their descendants moved further along the coast, circled India, and went to Indonesia and Papua New Guinea. They reached Australia about 45-60 thousand years ago. Other groups continued to leave Africa. Some traveled north through Central Asia about 35,000 years ago. Some of these early modern people turned west and founded the first settlements in Europe.
Mass migrations that led to the colonization of all habitable regions of the world took place before written evidence appeared, and even archaeological data are filled with gaps. How do we learn about the specific routes our ancestors followed?
It turns out that the migration of early humans is reflected in our DNA with incredible accuracy.
There are three different ways to determine the origin of genes. First, every cell in your body has mitochondria (cell energy stations). They contain a small ring genome that is separate from the DNA that is on your chromosomes in the cell nucleus.
The mitochondria in your cells come exclusively from your mother’s egg.
This is a key factor. The lion’s share of chromosomal DNA is combined from mother and father materials. Their individual genetic contributions are mixed, and it is, therefore, difficult to determine which parent these or other gene variants come from.
Mitochondrial DNA, however, comes exclusively from the mother and does not mix with anything. You inherit it completely: the mitochondria in your cells are basically identical to the mitochondria in your mother’s cells, which have been indistinguishable from the mitochondria in her mother’s cells etc. since time immemorial. Mitochondrial DNA is not mixed in every new generation, but a copy error occurs from time to time, which manifests itself as a mutation in mitochondrial DNA. Most of these mutations have no biological effects on our bodies.
Thanks to these extremely rare and therefore easily recognizable copy errors, we can learn something about our origin.
Imagine a woman. Let’s call her Nefertiti. She was born with a de novo (new) mutation in mitochondrial DNA. This is an indelible mark that is inherited from all Nefertiti descendants. This mutation is like a seal on a passport. Each of the descendants of Nefertiti will have this stamp. Therefore, all the people he wrote down will ultimately be descendants of Nefertiti.
Let us now assume that the great-great-great-great-granddaughter of Nefertiti, we call her Cleopatra, was born with another de novo mutation in mitochondrial DNA. This is a new passport stamp that will go to all Cleopatra descendants. At the same time, Cleopatra’s sister, we will call her Cornelia, did not have the same mutation as Cleopatra, but was born with a different de novo mutation. Hence, Cleopatra’s descendants can be distinguished from Cornelia’s descendants because different seals are attached to their mitochondrial passports.
Genetic ancestors Adam and Eve
If we look at a series of such stamps in a person’s mitochondrial DNA (ie a series of mutations), we can get a complete picture of who is coming from whom. Since people have wandered around the world in different directions, the stamps in their passports vary depending on where their ancestors live.
As a result, we get clues – breadcrumbs on the way to our ancestors.
The path goes back centuries to the so-called mitochondrial Eva, who lived in Africa about 170,000 years ago. All people come from her. But Eva is not the first woman to ever live on earth. She had many contemporaries, but it was her lineage that, unlike other women, has continued to this day.
The paternal inheritance process is similar.
While women receive the X chromosome from each parent, men inherit the X chromosome from the mother and the Y chromosome from the father. Since only they have the Y chromosome, it does not recombine and does not mix in every new generation.
In every man, the Y chromosome is almost identical to his father’s Y chromosome and his father’s father and so on back in time. As in mitochondria, mutations can occur in the Y chromosome that are transmitted to offspring and play the role of a series of stamps in the passport that determine the paternal lineage.
All men can also track their Y chromosomes down to one person – the Y chromosome Adam, who lived in Africa about 60,000 years ago. Note that the so-called couple – Adam and Eve – were actually more than 100,000 years apart. Mitochondrial DNA and Y chromosomes thus help to establish two branches of our family tree that go back in time.
If the entire family history is reflected in our DNA, would you like to undergo genotyping to find your family tree? The information obtained can lead you to have a deep connection to the past or even to take care of you.
Inbreeding and reduction of ancestors
By the way, the number of our ancestors grows exponentially if we move back in time. They have two biological parents, four grandparents, eight great-grandmothers and great-great-grandfathers, etc. The number doubles with each previous generation.
Many branches of the family tree cross – some of our ancestors crossed. Crossbreeding between relatives (inbred) among our ancestors was not very common when you look at some of the youngest generations. But if we dig deep into our family tree, second cousins, fourth cousins, etc., the cross between them is very common around the world. In fact, it quickly becomes inevitable. Genetics calls this phenomenon the ancestor reduction.
The ancestral forest of the world does not consist of neat rows of family trees; This is a huge lump of tangled shrub.
The degree of confusion of its branches becomes clear when we look at carefully examined family trees, such as B. various celebrities. Barack Obama is said to be a distant relative of President George W. Bush (twelve cousins), Warren Buffett, and Brad Pitt. It’s not that Obama belongs to a unique gene pool of famous people. If you return far enough in time, you will simply find out how much we are all connected.
The further we go into the past, the more people live at this time than our direct ancestors. The deeper we dive, the more likely it is that we will find a common ancestor. For example, scientists analyzed the genomes of a large sample of Europeans. It turned out that people living in opposite parts of Europe have acquired millions of common ancestors in the past millennium.
When you consider how many people are connected, at some point a person should appear who can consider all of humanity as their ancestor.
We have already talked about the Y chromosomal Adam, to which all paternal lines lead. He lived in Africa about 60,000 years ago. However, keep in mind that this is just a branch of your very confusing family tree – a branch that goes to the father of the father of the father, etc. If we look at all the branches of our family trees, we will find a much later common ancestor.
How far do you have to go back in time to meet someone who is the ancestor of all of us through one of the branches of our family trees? Given the continent of origin, historical migrations, and the frequency with which people tend to produce offspring with someone outside their hometown, scientists have calculated that the very last ancestor of all mankind by 55 BC BC lived. e. If we consider the generation to be 25 years old, he lived about 79 generations ago.
The person furthest away from you on the planet will be your 79th cousin.
If we dig deeper, we can also find a time when all people on earth were the ancestors of all living. This date is considered to be 2158 BC. e. That means every person on earth who 2158 BC BC lived. was one of our ancestors, whose family tree, due to luck, persisted until today.
What is the Difference Between Losers and Winners
What is the Difference Between Losers and Winners
Man is a social being, for his survival, he needs a group. Unsurprisingly, a large proportion of our instincts and programmed behaviors are geared toward building intragroup relationships — collaboration and competition for resources. There are three basic strategies for this interaction: take, give and exchange. More details – in this material, prepared according to the book “Find a Mentor“.
Find a mentor
Depending on the circumstances, we can use any of the three strategies, but, as a rule, each of us has one that we prefer.
“Exchangers” – these are those who act on the principle “I give, so that you give me too.” They are the majority in society. Their focus is justice.
“The takers” – focused on maximizing their own benefits in a relationship. The interests of others do not bother them.
Finally, there is also “Givers” – these people are focused on selfless help to others. Their focus is relationships.
Which of these strategies is more winning? Based on the research data, the following can be said. In the early stages, the takers are the most successful, while the givers are the outsiders.
As you move up, the picture changes to the opposite. There are almost no “takers” at the heights of success. But among those who have achieved outstanding results, there are unexpectedly many “giving”. The “exchangers” show stable average results at all levels.
People who are focused on their own benefit rarely reach the top. The reasons for this are obvious. A systematic disregard for the interests of others alienates those around them and increases hostility. In other words, within the framework of this strategy, each subsequent step repels friends and multiplies enemies. As a result, sooner or later, a person remains alone. It’s good if by that time he manages to reach the top.
But even so, success often looks like this: you are sitting in a tree, under which a pack of hungry wolves has gathered.
Another strategy of greatest interest is “give”. According to research conducted, most selfless and selfless altruists who are concerned about the welfare of others and are willing to help them to the detriment of their own interests are losers, which seems quite natural. On the other hand, it is the “givers” who achieve the greatest successes.
Why? Is this a game of chance, or is there some factor that distinguishes successful givers from unsuccessful ones? Such a factor really exists. And this is your environment. Both are equally trying to help everyone and do not expect immediate rewards. Both those and others in response receive the sympathy and approval of others. Some of them seek to provide a reciprocal service – they are “exchangers”. Some take advantage of the value they receive without considering it necessary to give something in return – these are the “takers.”
The difference between losers and winners is what happens next.
The loser continues to help everyone equally. And here everything depends on the case – how many “takers” will be in his environment. If not enough, he will survive. If there is a lot, it will quickly lose all resources and opportunities for growth. The winner, on the other hand, knows how to identify the “takers” and remove them from his circle, so a network is gradually formed around him, which together brings him more than he put into its formation. From some point on, it becomes a key success factor. And the sooner he learns to do this, the higher his chances of achieving outstanding results.
Prepared according to the book “Find a Mentor“.
What is the Difference Between Losers and Winners
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