~ The return of the mammoth
A serious problem:
George Church, a senior professor at Harvard, was sitting in a corner of the room. He was thinking about a burning problem of the world. Global warming. This is a problem that is slowly pushing the world towards a terrible future. The Pleistocene epoch or Ice Age ended on Earth about eleven thousand years ago (11,700 years ago). Then gradually the earth's temperature continued to rise. As human civilization has advanced, global warming has increased in tandem with it. Although the end of the Pleistocene era was due to natural causes, there is artificial intervention behind today's warming. But if it continues like this, how long will there be life on earth? Gradually rising temperatures will cause extinction of all living things, and humans will one day be added to the list of extinct animals.
Thinking about all this, George started sweating on his forehead. So much research, so much hard work, so many hours of experimentation in the laboratory - what does it mean, if no solution can be found to this crisis? What is human civilization, but one day it will end? Nothing to do? Will humans one day become extinct like mammoths? Suddenly lightning struck George. Well, if the mammoth can be brought back!
Siberian Permafrost Melting - Natural Time Bomb:
The most terrifying thing for the world at the moment is the melting of the Siberian permafrost. But what is this permafrost? Why did its melting rob scientists around the world of sleep? Let's see.
Three layers of soil are found in the Arctic region. These three levels are respectively:
(1) Active Layer
(2) Permafrost
(3) Unfrozen layer
Capillary water freezes in the soil as the temperature is less than 0 C for most of the year in this region. If the soil temperature has been below 0 C for two years or more, then that layer of soil with frozen capillary water is called permafrost. So understand that the temperature of this permafrost layer is very low. Animals and plants that died and were buried in the soil during the Pleistocene and later are supposed to be decomposed by microbes. But this decomposition is hampered by the fact that the warmth of permafrost is too low. We know that decomposition dissolves organisms and releases greenhouse gases such as carbon dioxide, methane, etc., which increase global warming. Now if the permafrost temperature continues to rise, the process of decomposition will resume. This will produce a lot of greenhouse gases. According to scientists, the amount of carbon dioxide trapped in permafrost is twice the amount of carbon dioxide currently in the atmosphere! In addition, methane is 86 times more capable of retaining heat from the sun than carbon dioxide. As a result of the continuous melting of permafrost, all these greenhouse gases are being released into the atmosphere, which is also causing the temperature to rise. This is why many scientists call permafrost a natural timebomb.
Feedback loop mill:
Have you noticed a strange thing in the melting of permafrost? In this case, both the cause and the effect are the same - increase in the temperature of the environment. Permafrost is constantly melting due to the ever-increasing temperature, and all the greenhouse gases that are emitted as a result of melting are again raising the temperature of the atmosphere, which in turn triggers the melting of the permafrost. For this reason, a loop has been created, which is called 'Feedback Loop' in the language of science. Surprisingly, permafrost not only contains greenhouse gases, but also contains large amounts of mercury (nearly 15 million gallons), a harmful neurotoxin. So now scientists are scrambling to figure out how to break this feedback loop.
Plastocene Park - Possible Solutions:
Surprisingly, the solution to this current problem lies in the ancient world. Russian scientist Sergei Zimov and his son Nikita Zimov have come up with a way to break the permafrost feedback loop. That is Pleistocene Park. Many may remember the name Jurassic Park. That's a lot of things. The two scientists plan to create the park by bringing back extinct Pleistocene-era animals to the Siberian steppe region. But how to bring back extinct animals? Is this at all possible? I say to those who have this question in mind, yes, it is possible! This process of bringing extinct animals back is called de-extinction.
But which extinct animal will be brought back? The answer will be given by that veteran geneticist from Harvard - Professor George Church.
✓DE extensions - The magic of genome editing:
This story of D extension but not today. In 2003, a wild goat breed called Bucardo was de-extinct in Spain. It was the world's first successful de-extension. But sadly, the animal did not survive more than a few minutes.
Let's go back several years. 1987 Yoshizumi Ishino, a researcher at Osaka University in Japan, and his colleagues, working in a lab, suddenly discovered a DNA sequence. The name of this sequence is CRISPR, which means 'clustered regularly interspaced short palindromic repeats'. This means that there are several palindromic sequences in which space is present. This part between the two palindromic sequences is called Spacer DNA. CRISPR was the first bacteriophage to attack a prokaryote. Studies have shown that this CRISPR is actually a prokaryotic immune system. Its job is to identify a DNA sequence of the invading virus and break it down so that the virus does no harm to it. An enzyme called Cas9 (CRISPR-associated protein 9) participates in this work. First, a small portion of the DNA of the invading virus is cut off. Then a slightly longer segment is created with that small part. These are called CRISPR arrays. Then RNA is prepared from that DNA segment through transcription. This RNA guides the Cas9 enzyme. This is why it is called Guide RNA or Guide RNA. That specific sequence in the DNA of the virus is found by Cas9 gRNA. Cas9 then renders the virus useless by cutting that particular part.
After continuous research on CRISPR, scientists realized that instead of gRNA, they could cut a programmed piece of DNA by attaching their programmed RNA to Cas9 and then add another DNA sequence there. This is called DNA editing. When a specific part of DNA that encodes a protein (called a gene) is edited in this way, the process is called genome editing or gene editing. Since 2015, CRISPR-Cas9 has been used commercially for genome editing.
Professor Church wanted to do this extension using CRISPR-Cas9. His goal was to bring back the extinct Woolly mammoth four thousand years ago. He needed a mammoth DNA sample. In this case, it is important to note that over time, DNA is destroyed. This rate of DNA decay is calculated to show that the half-life of DNA is 521 years. So some less than half the amount of mammoth fossils that are currently found are still intact. So how do you get the mammoth back? The mammoth's only surviving descendant today is the Asian Elephant. Now using CRISPR-Cas9, the genome of this Asian elephant's embryo will be edited and added to the mammoth's DNA. Then a new mammoth will be born from there. But the problem is, the mammoth we get in this case will not be 100% woolly mammoth. It will be a hybrid of woolly mammoth and Asian elephant with different characteristics of woolly mammoth. Such as fur cover all over the body, ability to withstand severe cold, etc. Now you can say, then what we got is nothing but a hybrid book. Yes, I believe it is a hybrid, but it is a special type of hybrid where the DNA of a living animal has been combined with an extinct animal. Hearing this, you may ask again, is it not possible to de-extinct all the animals that became extinct millions of years ago (such as dinosaurs)? The answer is no. Because intact DNA samples cannot be found from fossils from so many years ago. Besides, there are no descendants of animals that became extinct so many years ago. So it is not possible to bring him back at the moment.
How to solve:
By reading this you may have realized that there is a connection between this extension and the prevention of global warming. But how will it be? As I said before, a feedback loop has been created for the melting of permafrost. In order to break this feedback loop, we have to reduce the warming of the Siberian region. And to reduce this warming, we need to increase the amount of grass in the steppe grasslands of Siberia, as it was 4,000 years ago. This grass is able to reflect sunlight, so that the soil cannot absorb that sunlight and therefore the soil temperature can no longer increase. This phenomenon is called Albedo effect. In the case of grass the amount of this albedo effect is greater than in large trees. Now, if we want to increase the amount of grass in the area, we have to bring back the Pleistocene herbivores. The circulation and excretion of all these large herbivores will increase the fertility of the soil, resulting in more grass production. In addition to mammoths, extinct animals such as rain deer, bison, yakut horses, etc. are being considered in the future. It has been found that if all these animals can be brought back to the steppe grasslands, it is possible to reduce the temperature of permafrost by at least 15 degrees Fahrenheit.
Research on this topic is still ongoing. Hopefully, in a few years we will be able to see its real implementation. Until then, of course, we have to wait.