Science

Where do genes go after a human body is cremated? Are they present in the ashes?

For thousands of years people have been choosing the burial method for the deceased, after all, we have been talking about the idea of being buried in the ground for peace, that a person will be buried in the ground after death to get peace.

But nowadays, this type of burial is gradually being eliminated because it takes up a large area of land, so cremation is gradually becoming the mainstream way to dispose of the remains of relatives.

Where do genes go after a human body is cremated? Are they present in the ashes?

After a person is cremated, the remains can be completely disintegrated and what remains is only about 3.5% of the original mass. Generally speaking the ashes are around 3 kg for men and 2 kg for women.

I wonder if you have ever wondered where the genes in the body go after the human body is cremated? Are there still genes present in the ashes?

Today, let's explore this issue together.

First, let's understand what a gene is

Many people know the word gene from books, movies and films, but they know very little about genes, something that is invisible, untouchable and yet real in each of our bodies.

We know that the human body is composed of countless cells, which in turn are composed of cytoplasm and nucleus. The chromosomes in the nucleus are composed of DNA and proteins, and the small units on the DNA that determine biological traits are genes.

In descending order, the cell > nucleus > chromosome > DNA > gene

Where do genes go after a human body is cremated? Are they present in the ashes?

There are two overriding characteristics of genes.

  • First, the ability to faithfully replicate itself, or what we call heredity. Why do children look like their parents? This is the genes at work, to borrow the phrase that people often say is: plant a melon and get a melon, plant a bean and get a bean.
  • Second, the genes can "mutate", of course, here the "mutation" is not science fiction movies in which ordinary people become superheroes of the kind, but that "mutation" will bring some disease to the human body.

Where do genes go after a human body is cremated? Are they present in the ashes?

It is important to note that not all DNA has genes on it; only those segments of DNA that have genetic properties can be called genes.

Where do genes go after human cremation? Are there genes present in the ashes?

In fact, for DNA, it is actually very resistant to burning and is even used as a fireproof material. An Italian researcher, on DNA extracted from herring semen, was used to enhance the thermal stability and flame resistance of cotton fabrics.

The principle is that DNA will produce phosphoric acid and nitrogen-containing groups when heated, and the nitrogen-containing groups will release ammonia at high temperatures, and ammonia is flame retardant, which makes DNA have the effect of flame retardant.

Where do genes go after a human body is cremated? Are they present in the ashes?

Although DNA has a flame retardant effect, whether it can protect the genes inside from high temperatures needs to be analyzed specifically according to two different situations.

Crematorium crematorium temperature is still very high, from the body was pushed into the crematorium, until the end of the cremation, the temperature in the crematorium from 200 ℃ has been rising to 900 ℃, the cremation time lasts about half an hour, more than a hundred pounds of remains, after the cremation is left with two or three kilograms of ashes.

In the crematorium, the first thing to burn is the human soft tissue skin, followed by a variety of internal organs, the body's fat, protein, cells and other such organic matter in the role of high temperature, burned away. After the cells are destroyed, they have to face the DNA inside the cells, even if the DNA has flame retardant, it can not carry the burning temperature inside the crematorium.

Where do genes go after a human body is cremated? Are they present in the ashes?

The cells and DNA are burned away, and the genes in that are gone.

In addition, the ashes left after the incineration of the human body, the organic matter inside have been burned away, what remains is calcium, phosphorus, carbon and other inorganic substances, much less the existence of genes.

When you look at this, someone will surely say: who would choose to burn the remains in the open. This is really there, such as India.

The crematorium in India is basically open-air, and when the cremated remains are cremated, a pile of firewood is erected, and the remains are put on the wood and set on fire. This way of cremation is certainly not crematorium burned clean, after all, is open air, even if you add more firewood, the temperature of burning does not reach the high temperature of the crematorium.

Where do genes go after a human body is cremated? Are they present in the ashes?

Therefore, open-air burning will only burn out the surface tissues and internal organs of the remains, part of the bones remain relatively intact, not up to the effect of turning into ashes, plus the DNA has a flame retardant properties, there will be a small number of skeletal cells remaining in the bones, and the genes continue to remain.

How long will the genes be retained if the body chooses to be buried?

When a person chooses to be buried after death, the decay of the remains will gradually occur due to the influence of microorganisms, temperature, humidity, air and other factors, and the time of decay varies from organ to organ, generally ranging from a few months to several years. This period of decay is also the time during which genes exist in the tissues of various organs of the human body.

For the human body, the least perishable are naturally the bones and teeth. Since the main component of bones and teeth is inorganic salt, decay will not occur for a long time, and the genes in bones will be preserved for a long time with the bone structure intact.

Where do genes go after a human body is cremated? Are they present in the ashes?

Researchers at the University of Copenhagen had tested 158 leg bones containing DNA, and they found that the half-life of DNA in leg bones was 521 years. In other words, 521 years after a person dies, half of the DNA connections in the bone will be destroyed, and the remaining half remains intact in the bone, and the human genes on it do not disappear.

It is also important to note that if the earth's crustal plates settle so that the buried remains are rapidly closed and compacted into shape, it is possible that fossils may form, which would allow the genes in the bones to exist for a longer period of time.

Where do genes go after a human body is cremated? Are they present in the ashes?

Scientists then extracted a fragment of the world's oldest human DNA from a fossil thigh bone. After some research, scientists found that this ancient human ancestor, lived about 400,000 years ago. Combined with modern technology to sequence the DNA fragments in the bone, it took only two grams of bone powder to completely recreate the genome of this ancient human.

Say it at the end

As the saying goes, "Ashes to ashes, dust to dust," where the genes go after the body is cremated depends largely on how the cremation was done.

If burned for a long time at such a high temperature in a cremator, the genes in the human body will dissipate in nature with a wisp of smoke; if the open-air cremation method in India is used, the genes of the human body will remain in the harder bones due to insufficient burning.