Dinosaur can be brought back to living world?
“What if, millions of years ago, there had been a hungry mosquito that dined on a dinosaur and became trapped in amber, with its last super still in stomach. If one could recover dinosaur blood cells from inside that mosquito and then transplant it into an egg that had its own DNA removed, it might be possible to grow a dinosaur.” – Pilcher in 1980
The dinosaur’s blood that can be obtained by separating the mosquito that was entombed in the amber is of great value as DNA contains all the genetic information for the growth and development of an organism. By growing that DNA in an artificial medium, it is possible to obtain an actual living dinosaur in the 21st century. But, as said by another scientist,
“We do have mosquitoes and biting flies from the time of dinosaurs and they are preserved in amber but when amber preserves things, it tend to preserve the husk, not the soft tissues. So you don’t get blood preserved inside mosquitoes in amber” –Susie
So in other words “Jurassic Park” is not possible. But the process can be applied for the De-extinction (process of bringing back an organism that belongs to an extinct species or is either the closest relative of that extinct species) of other animals whose DNA is easily available.
On January 6, 2000 the last member of species Bucardo, named Celia was laid down to death by land-sliding of a stone. But the scientist had other ideas. They took the tissues of Celia from that place and hoped to bring her back to life.
A cell or group of cells were taken from a goat resembling Celia and DNA was destroyed by the UV rays. Then the DNA from the cells of Celia were injected into the goat cells by an electrical shock. After the cells had been prepared, the cells were placed into the womb of the goat and were allowed to grow.
Fortunately, the cells survived pregnancy and on July 30, 2003 one of the Celia’s clone was born. But, unfortunately, her health was not up to the mark. Her lungs had been grossly deformed and she died seven minutes later after her birth. But scientist were able to bring Celia back to life.
“To de-extinct an animal, you need a source of that animal’s DNA” –Pilcher
So, De-extinction, also termed as Resurrection Biology or Species Revivalism, involves creating an organism or bringing an organism back to the living world that has been considered extinct or otherwise endangered. Cloning and selective breeding are the two methods adopted for this process. However, genome editing may also paly its part in the technique.
The process applied for the resurrection of Celia was cloning. That is, the nucleus or the genetic material of extinct species is extracted and is placed into a cell of the organism who is the closest relative of that extinct species whose own nucleus has been destroyed to ensure that the resulting off-spring is purely the organism we want to obtain. After the cells being modified, they are placed into the womb and are allowed to grow.
An important thing to note is that for this method we require the cell or DNA of the extinct organism. So this method may be useful for the recently extinct species or for those who are at the verge of extinction (endangered species).
Selective breeding is the process by which the closest living relative of the extinct species can be identified and then mated selectively to produce the off-springs that will somehow express the characteristics of extinct species. But in this case the genome of the off-springs produced will still be different from that of the extinct species.
A subspecies of Zebra called Quagga was declared extinct in 1880. But scientists have revived Quagga using the selective breeding technique. As the new animal is not genetically identical to Quagga specie, scientist have named the new animal as Rau Quagga.
Genome editing in another technique that maybe applied to the de-extinction process. With the advancement in technology and development of more targeted techniques such as CRISPER-Cas9 it is possible to edit the genome of the closest living relative of the extinct species.
For this purpose, we require the genome from the extinct species. This is only possible if we have highly degraded and preserved tissues of extinct organisms. However, the technique involves editing the genome of living relative and replacing its genes with the genes from the extinct organism.
As a result, the off-springs formed will resemble the members of extinct species. But there are several limitations of this technique. As the genes of extinct organism will come from old, degraded tissues. The more degraded the tissue will be, the more fragmented the DNA would be and hence the more challenging the technique would become.
Additionally, as the genes will be inserted into the living relative, there will not be 100% surety of getting the extinct organism, as the genes from living relative will also be expressed. And also this technique is just an option and is not yet being utilized for De-extinction.
One of the potential candidate for De-extinction is Woolly Mammoth (Mammathus primigenius) from Ice Age. It is last in the line of mammoth species and its closest living relative is the Asian Elephant. It lived in the colder regions. Its preserved tissues and DNA led scientist to the idea that this organism could be brought back to life by using the techniques of cloning or genome editing.
The first technique involves cloning in which the host cell used would be that from an elephant and the rest of the process would be the same. The other method for the De-extinction of Woolly Mammoth involves artificial insemination, in which the elephant egg cell would be fused with the sperm cell from a Woolly Mammoth.
The resulting off-spring would be Elephant-Mammoth hybrid having characteristics of both the parents. And then these hybrids would be cross-bred to produce an off-spring resembling the actual Woolly Mammoth. Mammoth expert Adrian Lister questions the accuracy of the techniques and in addition to that he argues that there is not much habitat left for the Woolly Mammoth.
He also argues that the resources used in the whole process would be enormous and the scientific advantages of re-creating such species are still unclear.
More than 20,000 living species are considered extinct and the critics of De-extinction suggest to use the resources for the conservation of threatened as well as endangered species rather to use the same resources for the resurrection of the extinct species.
It has been calculated that reviving a single species could cost up to millions of dollars. In most cases the resurrection may have negative impact on the living organisms. For instance, the resurrection of Woolly Mammoth requires the contribution from the Asian Elephant as its egg cells are used.
Asian Elephant is itself considered an endangered species and if its members are used for the De-extinction of Woolly Mammoth, then in return Asian Elephant may itself become extinct. Moreover, the revived species may have a changed animal behavior than that of their living members as they are raised by other members and not by their actual parents. Last but not the least, reviving extinct species poses a serious harm to the modern flora and fauna.
As Dr. Malcolm says in Jurassic Park, “Just because you can doesn’t mean that you should!”https://www.technologytimes.pk/dinosaur-can-be-bring-back-to-living-world/Articlesbring,Dinosaurs,living,world“What if, millions of years ago, there had been a hungry mosquito that dined on a dinosaur and became trapped in amber, with its last super still in stomach. If one could recover dinosaur blood cells from inside that mosquito and then transplant it into an egg that had...Razmia ButtRazmia Buttrazmia.firstname.lastname@example.orgContributorI'm a student of BS Applied Biosciences at NUST, Islamabad.Technology Times