Lin Jianqing x surging asked
Jurassic World 3
From the mammoths and jagged tigers in "Ice Age" to the pterosaurs and Tyrannosaurus rex in "Jurassic World", the ancient behemoths that were once active gradually disappeared into the torrent of time with natural selection, alternating ups and downs. If there were technology today that could bring extinct species back to life, would you like it to come true?
De-extinction (also known as "anti-extinction") is a hot topic that has attracted attention and discussion in the scientific community and society. At present, there are three means to achieve the "resurrection" of extinct species: one is reverse breeding; The second is cloning through cross-species somatic cell nuclear transplantation; The third is to use gene editing technology to edit closely related species to obtain the genome of the extinct species as close as possible.
What are the latest advances in the technology of resurrecting extinct species, and what are the challenges that still need to be overcome? With these three technologies, can we really resurrect extinct species such as dinosaurs, saber-toothed tigers, mammoths, dodos, passenger pigeons and Christmas Island rats? If the resurrection of extinct species becomes a reality, what impact will it have on the planet and on humanity? The surging question invited Lin Jianqing, a lecturer at the School of Science of Shantou University, to talk about the possibility of resurrecting extinct species.
Can it really be resurrected?
@PappN Pan Xiaohua: If you clone dinosaurs, will there really be a situation that threatens the survival of human beings like in the "Jurassic Park" movie? What kind of cloning technique is it to clone an extinct species using the blood sucked by mosquitoes trapped in amber?
Lin Jianqing: Unfortunately, dinosaurs are almost impossible to be resurrected. The Scene from Jurassic Park will not be recreated because ancient DNA is only about 100,000 years old. It can be preserved in the permafrost for a long time, and the oldest record is 1.65 million years ago, extracted from the teeth of mammoths in the permafrost of Siberia. But dinosaurs lived far beyond that age.
It is even more impossible to extract dinosaur DNA from the blood of mosquitoes in amber, and the DNA of mosquitoes and dinosaurs has long been degraded.
@Surging netizen niIrqe: Mammoths have a specific living environment suitable for them. If resurrected, would it really survive in the current climate?
Lin Jianqing: In terms of climate, perhaps in high latitudes such as Siberia, it is possible, but the more important problem is that although only 4,000 years have passed (the latest assessment of the time of mammoth extinction), the local vegetation and animals have been completely different from the mammoth era, and simply releasing a mammoth or mammoth-Asian mammoth chimera is difficult to survive, and the entire upstream food network must be rebuilt.
Mammoth restoration simulation diagram. Infographic
@MagicWaltz: Are there any species that have been successfully resurrected?
Lin Jianqing: Yes! Spanish scientists used cloning to revive the Bucardo goat in 2003, but the baby goat survived for only 7 minutes before dying. It's a tragedy that the Bucardo goat is the only species that has so far gone extinct twice.
How to be resurrected?
@Nokkk: If previous creatures can be resurrected, does it mean that dead humans can also be resurrected?
Lin Jianqing: Who are the dead human beings you are talking about? Does it refer to the human beings who died in the hands of Emperor Qin Shi Huang and Emperor Wu of Han? Or do you mean the neanderthal races and others that have disappeared? If it is the former, then the resurrection of species we are discussing is two concepts, because modern humans have not gone extinct, then there is no so-called species resurrection. If it is the latter, the technology has theoretically matured to a certain extent, it can be revived or somewhat revived by gene editing, back-breeding, or cloning (if Neanderthal living cells are found again).
But the idea is crazy and involves too many ethical issues. I think the chances of achieving this are extremely small.
@Qixing: How likely is the resurrection of extinct species?
Lin Jianqing: This really has to be specific to the species, and the goal of resurrection. If you want to bring back a species entirely, then I think that of the three methods mentioned above, only cloning can be achieved, so the presence of living cells, such as the Brado goat, must be there. If it is just to bring back some of the characteristics and ecological functions of the species, I think it can also be achieved in the near future, such as Church George's Mammoth Resurrection Project, which is said to have successfully edited several key gene loci, and the Mammoth-Asian Elephant Chimera is just around the corner.
@Dongli Mengxiao: I want to know what is the current technical problem of resurrecting the creatures that have become extinct? If we start from the genes of the species's close relatives such as subspecies, can we create the extinct species by changing the differential genes?
Lin Jianqing: These two questions are very good! As mentioned earlier, there are three different technical approaches to resurrected species: reverse breeding, cloning, and gene editing.
The main problem with back-breeding is that the resurrection may only resemble or function like a chimera, genetically a completely different species, so it cannot be regarded as a resurrection in the true sense.
The technology of cloning is actually relatively mature, and the biggest problem is to find living cells and species (or artificial uterus) suitable for contemporary pregnant mothers.
The problem of gene editing technology is to overcome what we proposed this year, the genetic differences in the evolution of species will make some genetic information impossible to know and restore, as well as the current gene editing technology off-target problem, as well as the inability to achieve the editing of tens of thousands of gene loci at a time.
Gene editing through subspecies to revive extinct subspecies is a good idea to overcome the third point of many problems mentioned above. Of course, many people will think that the resurrection of subspecies is of little significance and is not cost-effective.
@Surging netizen YRzyUz: What does reverse breeding mean?
Lin Jianqing: The goal of reverse breeding (Back-breeding) is to concentrate some traits of ancestors into one individual through selective breeding between offspring, so as to achieve the reproduction of ancestral traits. Among them, the breeding of raw cattle is the most typical example of reverse breeding. However, we need to note that the Heck cow bred by the Heck brothers is not really a raw cow, but only has a similarity to the original cow.
@Kandagawa: The species after gene editing can only be said to be characteristically close to the extinct species, but can it be counted as the same species as this extinct species? Probably not.
Lin Jianqing: Yes, according to the current level of technology, through gene editing technology, only a limited number of genes can be restored.
Even if gene editing technology is developed to a very high level and can achieve any editing we want to do, due to the evolutionary gap between species, some genetic information on extinct species cannot be obtained, so it is impossible to restore extinct species through gene editing.
So, with gene editing, what we get is a chimera of extant species and extinct species, and maybe we will never be able to restore the extinct species itself.
Genetic evolutionary analysis of mammoths and modern elephants
The meaning of the resurrection
@For the moon to come to me: Why should scientists consider species resurrection technology? Since it has been eliminated in the natural selection, if it is resurrected, the food chain on the earth will be completely chaotic, right?
Lin Jianqing: Yes, if extinct species are resurrected and multiplied on a large scale, it will upset the existing balance of the Earth's ecosystem, just like the current invasive species. So, this is the ethical risk of de-extinction. To resurrect and release a species into nature, we must be cautious and cautious, not only large animals, but also the resurrection, transformation and release of plants and microorganisms must be very cautious.
@Stardust: What is the significance of doing these studies? Because it feels ethically questionable whether species can be resurrected, these technologies may not be available for hundreds of years.
Lin Jianqing: Regarding the significance of studying de-extinction ( anti-extinction ) , there is a summary in Torill Kornfeldt's book "Resurrection of Species", which I think is very reasonable, and it is directly quoted as follows:
1) New species have the potential to improve ecosystems and enrich species diversity, and benefit a large number of other species in their own way;
2, the resurrection of species project to bring hope to people, let people believe that the world will be a better place;
3. Humans will accumulate technology and knowledge in the process of research, which can be used to improve human health, improve food species and other fields.
Of course, the question of the significance of the resurrection of species is indeed a matter of opinion and is open to discussion.
@Give me back my nickname: In addition to satisfying the curiosity of human beings, what is the point of resurrecting extinct species?
Lin Jianqing: I think another role is that if a species has not been extinct for too long and the local environment has not changed much, then resurrection (or partial resurrection) can reintroduce its ecological function and avoid the collapse of the ecosystem due to the lack of ecological function of this species. For example, after a bird goes extinct, a bug that is its food may flood, at this time, if I resurrect the bird, can I avoid this ecological disaster?
Editor-in-Charge: Huang Yazhu
Proofreader: Liu Wei