Reshma Soman

IMS10046
De-extinction
Review
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De-extinction
De-extinction, a fantasy or reality? Back in 1990 when the book Jurassic park by Michael
Crichton got published genetic resurrection of extinct animals was purely a science fiction.
But with the advancement of cloning and other genetic techniques this fantasy is now a
reality. Still resurrecting dinosaurs is a fantasy only as it got extinct approximately 65
million years ago, so impossible to extract full genome. Although a successful de-
extinction where the resurrected animal live long enough has not yet took place till now,
scientific community is waiting for that moment. Briefly defining what is de-extinction,
de-extinction is bringing back extinct species using scientific techniques.
The most successful project till now is the revival of Pyrenees bucardo goat, a wild goat
which got extinct recently as in 2000. Miserably the clone didnt survive for more than a
few minutes. That is the main difficulty faced by cloning of extinct species, the
incompetency to produce healthy animals. Once the de-extinction process is started, it is
not an easy venture. First trouble is finding full genome of the extinct species. Even though
the probability of getting full genome retrieved from a recently extinct species is high
compared to anciently extinct ones. The next burden is the risk of formation of chimeric
species bearing mitochondrial DNA from host and genomic DNA from donor. Only the
close relative of the extinct species can act as the surrogate mother for the clone, we cant
take any random animal and perform interspecies cloning. Even if a suitable surrogate
mother is found, the likelihood of miscarriages and unhealthy offspring is inevitable. Most
of the interspecies clones suffer from respiratory problem, reason or cure for that is not
find yet.
Another animal waiting for resurrection is woolly mammoth which inhibited the lands of
Siberia around 12000 years ago. These animals preserved the grasslands there by breaking
down soil and fertilizing with their manure, and now moss has taken over the entire area
and made it less fertile. A highly preserved fossil of this animal was found from Siberian
tundra. Scientist are searching for the presence of any live cell. If found mammoth will be
cloned using elephant, their living close relative as the foster mother. The chance of finding
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a live cell is close to zero. But it will be adequate to get the full genomic DNA for
conducting cloning.
The prime most problem in the de-extinction programme is solved to some extent by
ancestral gene resurrection. Animals that got trapped in amber or ice are preserved fossils
which have the potential to retrieve the entire genome. Back in 1989 Svante Paabo did
experiments related to extraction, characterization, molecular cloning, and enzymatic
amplification of ancient DNA. He extracted DNA from samples of different time periods,
including from extinct species. The amount of extracted DNA was very little and those
DNA fragments suffered from oxidative damage. But now we have technologies to
engineer the entire genomic DNA of an organism by placing together the genes
corresponding to the traits of the organism. For example, passenger pigeon is extinct by
the end of 19
th
century, retrieving the full genome of the bird is impossible, but scientist
are planning to make the entire genome by placing together the available fragments and
splice the close relatives gene to get the features of passenger pigeon. Many advanced
work are going on the field. Soon, one of them may find result for their effort. Many more
animals are waiting to come back from their grave. Passenger pigeon, woolly mammoth,
bucardo are the few among those. Solving the current problems in de-extinction and
bringing them back to life is within hands reach. Lets assume even with all these odds
de-extinction is made possible. The question is whether the world is ready to welcome
these animals?
Why de-extinction? Ones which are destroyed by us also needs to be fixed by us. The root
for the extinction of most species being extinct today are human activities. So when we are
responsible for their extinction we are liable to prevent it or reverse the damage, through
de-extinction or by some other means. But is it the appropriate and adequate solution? De-
extinction is a distraction to conservation. While de-extinction is catching most of the
attention, people are forgetting to conserve what is present now. It is conservation which
demands much more attention than de-extinction. If we cant conserve what we already
have, how are we going to protect the resurrected species? How do we assure that they
wont get extinct again? If we cant protect them getting extinct again, all the effort is futile.
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A mere waste of resources and time, and by the time this realizations occur, there will be
nothing left to conserve.
The ecological conditions before the extinction of these species is different from that we
have now. Granting we succeed in resurrecting extinct species what are we supposed to do
with those species? To release them in nature is a highly questionable approach. First
problem is their survival in the wild habitat. The likelihood of these species surviving in
the ecological conditions sustaining now is very low. We are resurrecting them to getting
extinct again, which is highly unlikely. With deforestation and global warming spiking the
earth, is there anything called home for them to come back. Their natural home is being
destroyed by humans. Another problem is the effect of resurrection of a species on other
species that inhabit their natural home now. These resurrected species are genetically
modified species, chances of they turning into invasive species is also possible. What if the
resurrection of one species lead to the extinction of other. The approach taken for the
resurrection of passenger pigeon may lead to creating a new species which resemble the
passenger pigeon. What benefit it is going to make by creating such a new species, where
the chances of it turning invasive are possibly high.
If the resurrecting species is having some medicinal value it may have some benefit, but
that benefit is circumscribed only to human beings. Human beings are not the only species
which inhabit earth. Earth belongs to other organisms as well, they have the same right as
us. There are wide protest against releasing wild animals which bred under captivity back
to the wild by the people who inhabits the area as they dont want new animals to hunt
down their cattle and get into trouble. Same may occur in this case also. Then to keep in
captivity? Keep it for people to gawp at for entertainment? It is not going to help
conservation in any sort, as the main aim of conservatory biologist is the enrichment of
animals in the nature.
For the endangered species which fail to breed in captivity, cloning can be used to increase
their number. Another problem caused by de-extinction technique is the lack of genetic
diversity. So when these resurrected species got hit by some disease it will get spread easily
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and would wipe out the entire species. In a diverse population this wont happen, as there
will be some section of species resistant to that disease.
One more problem is the attitude of people, if they start hunting of these animals like before
it would pace up their extinction rate to much larger extend. Thinking this is not natural, it
is not mans job to be done. The ethical concerns, maybe these species are meant to be
extinct in accordance with natural selection, the survival of the fittest. That will be a mean
way of justifying the deeds of man. There are evidences to claim that the extinctions which
are happening now are much more compared to the background extinction rate in the past.
It may be less than those during the mass extinctions, but all these are demonstrating
humans influence in these extinctions. So it is our duty to rectify the damage that is done.
And how many individuals will be created by using this project? A handful of individuals
only, some 50 passenger pigeons or 15 mammoth for maximum. Are they going to breed
naturally? Spending huge amounts of money for bringing back a few number of individuals
doesnt seem like a good idea. How will these organisms have the trait of the original
extinct organism without any parental organisms? Passenger pigeons are different from
normal pigeons in many ways, food, how they fly, how they form flocks, all are different.
So in practise the brought back species will be an entirely new species. And it can be a
vector to some pathogen causing disease to other organisms. So it is essential to validate
the techniques before practising it to make these organism. For validating the techniques
take two living species which are closely related and assume one is extinct and try to
resurrect it using the other species as host and see how much the identical the offspring is
to the first species. If they are identical the technique is perfect to be implemented.
Resurrecting the extinct animals will solve only half of the problem. There may be some
other organism which depended on the extinct animal I someway and suffering as these
animals doesnt exist now. For those animals the resurrection of extinct species may be
beneficial. But even if some organism depended on extinct species in the past, they would
have evolved to cope up without the extinct species by now. If not, those species dependent
on the extinct species will be declining in number by now. Thus will help them a lot. It is
giving a second chance for these declining species together with the resurrected species.
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There arises a special condition called conservation dependency for the resurrected animals
where they need constant attention. We have to take care of them from getting perish again.
There should also be some classification which all species that can be resurrected. The
extinct species can be classified in to those organisms which cannot be revived and those
which can be revived. The second type can be further classified into species that should be
revived and that should not be revived. Only those species which can be and should be
revived should be chosen for de-extinction that too much cautiously. Those species which
are good candidates can be resurrected.
Another bad effect of de-extinction is that it will weaken the effort of conservationist to
conserve the endangered species as there will be a feeling that even if they got extinct they
can be resurrected by de-extinction. And it will in turn support destruction of natural
habitats. The funds provided for de-extinction projects are too high. It wont cost even half
the amount to conserve the habitats and endangered species. The attention got by de-
extinction is greatly because of attraction to new things, a mere surprise element of seeing
extinct species alive. On viewing in terms of entertainment value, de-extinction is highly
recommended.
For those species that doesnt have a mating pair like Celia, the last bucardo goat de-
extinction technologies could be used to clone a mate and will be helpful to prevent that
organism from getting extinct. If we are resurrecting animals that go extinct recently, we
would know a lot about their habitat, behaviour and food. Conservationist know how to
breed them and increase their numbers, this is not the case with animals that got ages ago.
Summarizing, de-extinction is both a hope and a pomposity. Just because we can do it
doesnt mean we should do it. It is good to correct our mistake by bringing back species
that got extinct by human intrusion. But we should take into account how it will affect
environment and other species in the habitat and also. And something should be done about
increasing the genetic diversity also. And those species that are brought back should be
capable of breeding on their own. What we are making will be replicas only, something
that may seem resembling but not the one that is lost long back, the way they behave cannot
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be predictable. If the problems raised by de-extinction can be solved it will be a hope for
extinct and endangered species
References
(Paabo, 1989) Ancient DNA: Extraction, characterization, molecular cloning, and
enzymatic amplification
(Zimmer, 2014) http://ngm.nationalgeographic.com/2013/04/125-species-revival/zimmer-
text
(Loi1, Galli2, & Ptak, March 2007.) Cloning of endangered mammalian species: any
progress?
(Lee) Can cloning save endangered species?
(Tedx) http://tedxdeextinction.org/ videos