Could It Be Possible to Bring Back Extinct Species?
Anika Patel University of Southern Californiaanikapat@usc.edu
Author’s Biography: I am currently a sophomore majoring in Computer Science and Business Administration. Although the subject matter discussed in the following article does not pertain to my major, I have always been very intrigued by the concepts of cloning and de-extinction.
Abstract:
De-extinction, or the process of bringing back extinct species, is a concept that continues to grow. Recent research has proven that de-extinction can be executed through methods of cloning or genome altering. In fact, these specific processes have already been performed by multiple scientists, and the results can be described as exceptional discoveries that only mark the beginning of de-extinction. Although there is still a lot to be explored and studied on this specific matter, in the very near future we could be living amongst “resurrected” species. The whole process behind de-extinction not only notes how far our society has come technologically, but also reveals the importance of engineering in our world today.
Key Words:
Cloning, de-extinction, genetic engineering, genome editing, somatic cell, genome, DNA
Introduction:
When the last animal of a species perishes, the species is proclaimed as extinct. However, current research in genetic engineering and cloning may allow certain extinct species to soon reappear.
Both cloning and genetic engineering are concepts that have been heavily explored in these past few years. Some of these research projects have allowed for us to gain valid information on methods that may in fact bring back extinct species, or a species that shares similar genetic makeup to an extinct species. Although it is not possible at this time to bring back every extinct species, it is still very much possible to bring back species that have recently gone extinct with the methods of genetic altering.
The Process:
When considering de-extinction methods, there seem to be two that sound rather promising.
Cloning and genetic engineering are both very different, yet effective approaches to deextinction.
Cloning
Cloning may be a better approach to extinction prevention for endangered species, as their living cells are easier to obtain. Cloning can further be described as “somatic cell nuclear transfer” which creates a homogeneous genetic copy of the specific organism being replicated [1].
Somatic cell nuclear transfer allows for the nucleus of an adult somatic cell to be transferred into an egg cell, so that the egg cell can reprogram the somatic cell into a stem cell [1]. After this process of somatic cell nuclear transfer, the organism that is created should have an indistinguishable genome sequence to the organism that possessed the adult somatic cell [1].
Although the idea of cloning seems to be a promising approach to de-extinction, less than 5% of the cloned organisms have developed into living offspring, due to complications created after birth [1]. Another drawback to cloning is the fact that it requires living cells, which is not very easy to come by regarding extinct species [1].
Genetic Engineering
The second, possibly more effective, approach to de-extinction is to use genetic altering and genome altering to our advantage [1]. The recent acceleration in ancient DNA extraction and sequencing technology is making it extremely possible to produce complete genome sequences of species that have already gone extinct [1]. The best approach to this reconstruction is to compare these genomes to genome sequences of living species that are of close relation to the extinct species [1]. After finding where the genomes do not align, between the extinct and living species, genome altering can be applied to make the existing species as similar as they can be to the extinct one [1]. However, genome engineering is only plausible due to DNA, but the issue with DNA is that it becomes fragmented overtime [1]. Climate has a direct relationship with the rate of time DNA becomes fragmented; the decay of DNA is much slower in colder climates than it is in warmer climates [1]. This could also indicate that extinct species from colder environments have a higher chance of participating in de-extinction.
The image above further displays the process behind genome editing, as it shows how specific areas of the elephant’s genome is altered to make it closely match the traits of a mammoth. [1].
Has This Successfully Been Performed Before:
Scientist George Church and his lab at Harvard University, recently announced that they had their first success in altering elephant cells to make them closely match gene sequences from the woolly mammoth [2]. This study was performed by replacing certain elephant genomes with that of the mammoth [2]. George Church is striving to create elephants that can adapt to cold
climates, with genome altering; he plans to replace elephant genomes with those of the mammoth’s [2]. If this experiment is successful, these mammoth-like elephants would be able to enter previously mammoth-inhabited environments [2]. This would be extremely helpful, as it would allow elephants to inhabit at a span of habitats, and it would also help to reestablish ecological relationships that were unfortunately neglected after the extinction of mammoths [2].
The Importance:
De-extinction could rehabilitate many of the key tasks that these extinct species once performed for the environment, which could also further aid other species in their ecosystems [3]. Additionally, the mere idea of de-extinction reveals our society’s current technological advancements. Knowledge regarding de-extinction simply shows us what our current technology has the power to do, and this may also unfold more scientific discoveries on preserving species. There is also no doubt that many species that have gone extinct are due to human interference; that being said, it may be the responsibility of humankind to bring back these species, if attainable. A plethora of species, that are currently being presented for de-extinction, were driven to extinction due to human interference [5]. Even though the past cannot be undone, humanity should make up for the wrong that was committed to these species[5].
Could We Bring Back a Dinosaur?
The longer a species has been extinct, the harder it is to recover its DNA. With that, it will undoubtedly be a much greater challenge to bring back dinosaurs. However, there have been many recent studies on bringing back dinosaurs, and we may be very close to creating a dinosaur-like organism. Paleontologists have concluded that birds are the closest progeny of dinosaurs [4]. If this is true, birds may have an evolutionary relationship with certain dinosaur species. With that, we can replace areas of a bird’s genome to make a new species that replicates a dinosaur, similarly to George Church’s lab.
Paleontologist Jack Horner further explored this idea when he created his plan to resurrect dinosaurs [4]. However, Horner’s approach to the de-extinction of dinosaurs slightly differs from the processes that were earlier discussed. Horner plans to manipulate the early development of bird embryos to transform them into dinosaurlike beings through a process known as reverseengineering [4]. The bird that was the most ideal for this experiment seemed to be a chicken; this was most likely because there is already a lot of evident information available, regarding the biology of chickens [4]. This approach is further supported by a team led by Yale professor, The
Bhart-Anjan Bhullar, and Harvard biologist, Arhat Abzhanov, who have been conducting experiments and research on transforming chickens into dinosaurs [7]. Essentially, they added and omitted specific traits from the chicken in order to create an organism that closely matches the traits of a dinosaur. At specific embryonic stages of the chicken, they blocked certain “birdspecific” traits from forming, with the use of “molecule inhibitors”; some of these specific traits of the chicken were its snout and feet development [4][7][9]. Although the outcome of this process may produce a dinosaur-like organism, it will most likely not look like the traditional dinosaur; the organism created will be the same size of a chicken and would require further genetic altering to replicate the large size of extinct dinosaurs.
Limitations:
Some Species Are Harder to Bring Back Than Others
As mentioned earlier, certain species may be harder to bring back, as they may have more areas in their genome that do not align with their relative species. Additionally, not all genomes are currently available to examine DNA also remains a challenge to recover, as some species were preserved in hot and wet environments [1]. It has been found that colder climates are better able to preserve extinct species, making more of their DNA available. Another issue could be that they have simply been extinct for too long, and there is little to no recoverable DNA left of the species. Gene altering is also a very timely process; there are sometimes an immense number of altercations that need to be made between the genomes to make the new species as closely identical to the extinct species [2]. For example, the genome of a mammoth is over four billion base-pairs in length, making the process of mammoth de-extinction an extremely lengthy process [8]. Lastly, genetic altering is a rather costly process; for example, J. Craig Venter created an entire lifeform when he and his team produced a finalized “genome of a tiny, free-living
bacterium,” [8] However, this process ended up taking fifteen years and cost around forty million dollars to complete [8].
Ethics:
With the idea of de-extinction becoming more popular in recent years, some critics have raised concerns regarding ethics. One of these concerns is that de-extinction is an “unnatural” process, as it is something that does not normally occur on our planet [5]. A more popular ethical concern is that de-extinction could prompt animal suffering. Since there is no way to predict how these new species will react to their environment, it cannot be guaranteed that de-extinction will not have any negative effects on the newly created organisms [5]. Similarly, we do not know how human beings would be affected by de-extinction, if these new engineered species are let out into the world, or if they escape; could they be a threat to human health? Lastly, de-extinction methods have also been compared “to playing God;” some individuals believe that certain things should not be controlled by mankind, specifically life. These ethical concerns regarding deextinction will most likely create more discussions in the coming future and may also be a conflict that researchers and scientists will likely face.
Future Plans and Research:
As for the future of de-extinction, there is still much to be uncovered. In fact, there are many scientists that have stated that extinct species will soon permanently exist in our society In fact, Yale Professor Bhart-Anjan Bhullar even went as far as to say that “somebody’s going to definitely bring back Neanderthals” [11]. Although now this may seem very unlikely, with the technologies that are currently emerging, this may very well be possible. However, there are a few issues that still need to be addressed in the coming future; if “resurrected” species are to
reappear, specific parasites may also have to be brought back [6]. The discussion regarding parasites has often been left out, even though it is very important to consider for de-extinction [6]. Although parasites are often seen as menaces to an organism, they are essential to organisms and ecosystems [6]. With that, further research still needs to be conducted on de-extinction, and parasites should also be further examined for future discussions. The emerging genome altering tool called “CRISPR/Cas9'' will also play an extremely vital role in the future of de-extinction, as it would allow scientists to have an easier approach to examining an organism’s genetic and evolutionary history [7]. CRISPR/Cas9 also acts as “molecular scissors” as it cuts specific sections of DNA, where necessary or unnecessary genes can be added at the area of the cut [7]. Although there are a few issues that still need to be addressed, technology has greatly advanced in recent years, and it is crazy to imagine that we will soon be living amongst resurrected species.
Work Cited
[1] B. Shapiro, “Pathways to de‐extinction: how close can we get to resurrection of an extinct species?,” Functional Ecology, vol. 31, no. 5, pp. 996–1002, 2016. Available:
https://besjournals.onlinelibrary.wiley.com/doi/pdfdirect/10.1111/1365-2435.12705
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https://genomebiology.biomedcentral.com/track/pdf/10.1186/s13059-015-0800-4.pdf
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[9] B.-A. S. Bhullar, Z. S. Morris, E. M. Sefton, A. Tok, M. Tokita, B. Namkoong, J. Camacho, D. A. Burnham, and A. Abzhanov, “A molecular mechanism for the origin of a key evolutionary innovation, the bird beak and palate, revealed by an integrative approach to major transitions in vertebrate history,” Evolution, vol. 69, no. 7, pp. 1665–1677, 2015. Available:
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