The easiest way to ensure that an entire community is not wiped out by the same genetic disease is to keep marriage not confined to the same community. The more variety there is in the DNA sequence, the healthier the community will be. Today we know that genetic diseases can come through both men and women. We even have the information that if there is a pattern in the DNA that increases the chances of a disease (the data is mostly correlation data, that is, if there is such a disease, such and such DNA has been seen but only that DNA format may not be the cause of the disease). However, researchers advise that it is better to show once and for all whether there is a DNA format related to certain diseases. Then there will be some convenience in making decisions like choosing a spouse or having children.
Where do we come from?
According to popular belief, Indians are divided into two groups. A group of Dravidians, they are the original inhabitants of the subcontinent. Another group of Aryans, they came from Europe.
Is that true? How do I know it’s true?
DNA remembers everything
Inside each of our cells is a slender, long ribbon-like DNA box that holds our biological information in a box. Although not completely, it controls some of the characteristics we have, physical, mental or character, that we inherited from our parents, that they inherited from their parents, and so on and so forth.
If the captive information in the DNA could be read, much would be known about our past.
With this information within reach, I want a few cells empty. A few drops of blood, a little bit of banana or tissue, a few hairs, teeth – each of these has enough cells, from which it is possible to get enough DNA. Many questions about the past can be answered by looking at the information in that DNA.
A reading of the DNA sequence of a large population reveals that much of it is the same (or the same in many people). In that order, there are differences in a few places. That is why all human beings have the same limbs. Everyone has eyes, mouths and noses, but they have to look different from each other.
Examination reveals the same pattern or pattern in the sequence of DNA from one generation to the next. That is why in the same family, all the characteristics of grandparents, such as the structure of the nose, remain the same.
The exact role of 99.8 percent of DNA, or what part of DNA is responsible for a trait, is still unknown. Yet the information underlying this sequence is useful to researchers. Researchers from the lab of Dr. Kumaraswamy Thangaraj of the CSIR-Center for Cellular and Molecular Biology (CCMB) are among such curious researchers. They look for similarities in the DNA of different populations around the world. From this they try to find a relationship between one community and another. What they found by researching in this way is quite unexpected. Quite different from what I knew about the past of the Indian people.
India has 4635 ethnic divisions out of its huge population. Their language can be divided into four categories: Dravidian, Indo-European, Austro-Asian and Tibetan-Burmese.
Let’s see what their DNA says. Does their DNA sequence shed light on any relationship between them? Or are they the descendants of the two ancient groups – Aryans and Dravidians?
The beginning of the Indian people
Researchers at CCMB found that the Indian population is rooted in two distinct groups – the Primitive South Indians or Ancestral South Indians (ASI) and the Primitive North Indians (ANI). The journey of these two communities started from the continent of Africa, but their journey was different.
On the first voyage, people arrived in India from Africa along the coast. Some of them settled permanently in South India and started the primitive South Indian population. Some went to the Andaman Islands (they still exist there). And a part went further towards Australia, where they introduced the primitive people or nation of Australia.
On the second voyage the people set out from Africa to the north. One group went to Europe, another group came to India across the Middle East and created the primitive North Indian population.
He was talking about 65,000 years ago when a group of people along the coast created a South Indian species from Africa to India.
Exactly how many years after the second voyage, it is still a matter of research.
Until 4,000 years ago, these two species gave birth to separate species. They still did not mix with each other.
This was followed by a mix of primitive South Indian and North Indian populations over the last 2000-4000 years. This is the creation of today’s population.
Needless to say, the story we are hearing about the origins of the Indians needs a little reversal.
It is not that one of the first generations of mankind started in India. Two branches of the same population came to India from the same continent in two completely different ways and spaced across two separate places. We all come from those two groups (primitive North Indians and primitive South Indians). Then of course more new groups came to India, but their contribution to the DNA of the inhabitants of India is limited.
This is not the end
The study also found that in the last 2000 years, most groups have restricted marriage and procreation to themselves. Which is why there are so many similarities in the DNA of these groups.
With the exception of germ cells, all other body cells make two copies of DNA, and these two copies are not exactly the same – each copy is obtained from the same birth parents. Often one DNA increases the risk of disease but another copy of DNA can protect against the same disease. We call those who have such a disease a carrier. This means that they will not suffer from the disease themselves but can pass the disease on to the next generation.
In the case of a child born from two carriers, there is always a risk. Their two copies of DNA may be the ones that predict or confirm the disease. Even if it is not, at least they are likely to be carriers of the disease. This has led to the emergence of a number of recessive diseases, a disease that can be passed from one generation to the next. For example, alkaptonuria or sickle cell anemia. Or group-specific diseases such as Handigaru disease in Karnataka.