For a number of years now, we have had people like Greta Thunberg et al from around the world ringing the alarm bells on climate change. While I do believe that it is true that our climate around the world is changing and that, to a degree, our activity as human beings has had an effect on this, I do not agree that it has been only us that have been to blame. Throughout history, and prehistory, the climate of the world has been ever-changing. The average temperatures on earth during the middle ages, for example, were way warmer than they are now. I believe that it serves certain political purposes these days to cry foul regarding certain industries' impact and that these are far more dangerous than the effects of changing weather patterns on our society. But I digress. Of course, we should do what we can to minimise the impact of that which we do on the world we call home.
People seem to think that the greenhouse effect, and the warming of our world has everything to do with us adding carbon dioxide to the atmosphere. Whether by industry, agriculture, or indirectly, it is this that has led to the advent of the term "carbon footprint" and its application to everything we do. However, it is shortsighted to believe that carbon is the only culprit. Methane, by comparison, is four times more impactful in terms of the greenhouse effect it creates as it is introduced to our atmosphere. And as the world gets warmer, more methane is being released. And this has nothing to do with anything that we have done. As it turns out, the permafrost in the northern hemisphere is melting, and it contains far more dead organic material then we could have ever imagined. Everything that has ever lived and died in that part of the world has been frozen in, what has been up to now, one big ice cube. And with the melting of the permafrost, methane has slowly been releasing into the atmosphere in staggering amounts. What can we do, you may ask? It turns out that you stop 1600 billion metric tons of carbon from entering our atmosphere by resurrecting a long dead friend.
As recently as 1650 BCE, we shared our world with woolly mammoths. It is clear from paleolithic cave art that humans and mammoths lived amongst each other, and that humans relied on the mammoths as part of their equation for survival. It is also quite clear, however, that humans helped to bring about the eventual extinction of this important neighbour. There is evidence that humans harvested mammoths as a source of protein, used their tusks for arts and other luxuries, and employed their dead bones and tusks in the construction of dwellings. Given their massive size and slow reproductive rates many believe that human hunting was one of the few major causes of the mammoths extinction. Natural climate changes were a factor as well, shrinking the mammoth's available living habitat spaces. The animal was basically being geologically sequestered by the earth, forced to live in ever tighter areas of land. This caused the genetic pool to shrink and problems related to inbreeding eventually began to occur. Eventually, the planet's mammoth population was reduced to small communes of about 500 to 1000 each one on Southport island just off the south-west coast of Alaska, the other Wrangel island of the North East of Russia. These were the last to die out.
Why am I telling you about woolly mammoths? Well, as it so happens, there is a company known as Colossal who believe that in order to decelerate the melting of the Arctic permafrost, and prevent the emission of greenhouse gases trapped within the permafrost layer – 600 million tonnes of carbon annually – we need to reverse now over shrubbed forests back into natural Arctic grasslands which would help with carbon emissions. We need to restore the Siberian Steppe to foster an ecosystem that can maintain its own defences against climate change. And, as we have seen in recent times when we reintroduced wolves into Yellowstone Park, we need to re-establish the balance in nature by reintroducing species to that area that were once the key to maintaining its unique resilience. We need to bring back woolly mammoths!
How does one bring back a specie that that has been dead for over 4000 years? The answer lies in genetics. Unlike the dinosaurs which left us evidence of their existence primarily in the fossil record, Ice Age megafauna predominantly died and were frozen where they fell. As has been discovered in the boneyard in Alaska, it often accompanied catastrophic events leaving hundreds of carcasses there for us to find and extract genetic material from. Using CRISPR/Cas9.
So what is CRISPR/Cas9 I hear you thinking? It is a revolutionary new gene editing technique which has made it easier, cheaper and more efficient than previous strategies for modified DNA. The term stands for clustered regularly interspaced short palindromic repeats / CRISPR associated protein nine. The names reflect important features identified during its discovery, but don't tell us much about how it works, as they were coined before anyone understood what it was.
CRISPR/Cas9 is a system found in bacteria and involved in immune defence. Bacteria use CRISPR/Cas9 to cut out the DNA of invading bacterial viruses that might otherwise kill them. Today, we've adapted this molecular machinery for an entirely different purpose – to change any chosen letter(s) in an organism's DNA code. Remembering that animals and plants are composed of millions of cells, each cell containing the same DNA, we then start at the beginning and end of the genome while there is only one cell – a very early embryo.
So, all we need is a giant microscope and a tiny pair of scissors. And that is basically what we use. Cas9 is the technical name for the virus destroying "scissors" that evolved in bacteria. The CRISPR part comes from repeat DNA sequences that were part of a complex system telling the scissors which part of the DNA to cut. Thus, we target our Cas9 scissors by linking them to an artificial guide that directs them to the matching segment of DNA. Remembering that DNA comes in two strands, with one strand fitting alongside the other, we make a guide with a code that will line up with only one part of our three billion base pair long genome. It's like a "Google" search. It's very possible for our guide to comb through vast amounts of genetic material to find the one section it matches exactly. Then, our "scissors" can make the cut in exactly the right place. Once the Cas9 scissors cut the DNA just where we intend, the cell wall trying to repair the break using any available DNA then fine. So, we also inject the new gene we want to insert. You can use a microscope and a tiny needle to inject the CRISPR/Cas9 together with the guide and the donor DNA, the new gene.
Getting back to our woolly mammoth for a second, we know that they were cold resistant herbivore mammals. They were warm-blooded creatures that could survive in freezing temperatures. They were large and slow-moving, with short compact ears to prevent heat loss, insulated by two layers of thick fur to keep the blood warm, along with staying rather active, consistent with their migration and foraging activities. We know by way of the remains that we have unearthed that, apart from the very large tusks and the furry covering, mammoths resembled Indian elephants in terms of their size and shape. Thus we have not only a modern day host for birthing our first specimens of the resurrected mammoth species, but also a donor for whatever DNA may be missing from the eventual genome. I did mention that there were 4 billion base pairs!
If what I said thus far has not left your jaw dropped firmly to the floor, the timeline may astound you. Initially, the idea was to re-wild 100 mammoths to Russian Siberia. This would happen as early as 2024. Yes, that is next year! But due to the worldwide political situation, an alternative site has had to be identified, pushing the date back to 2027. Pleistocene Park will become a reality within my lifetime and, unless you find yourself in God's waiting room, you may still live to see the Siberian tundra restored along with animals that have thus far only existed in the imaginations of Pixar's film makers. I, for one, look forward to welcoming Manny and Ellie back into the real world, along with their brood. Long may they roam the earth!