Notes

What is it?:
De-extinction is the process of bringing back extinct or critically endangered species of animals. This is also known as 'resurrection biology'. It is a groundbreaking area of study but also very controversial due to the nature or resurrection and as a result there is a large amount of ethics and differing views surrounding it. We are in the 6th great extinction event, which scientists call the Holocene extinction or Anthropocene extinction. In which there has been 875 species that have been reported as extinct. Due to species-area curve, which is a graph that depicts the relationship between a habitat and the amount of animal species found in it, there may be up to 140,000 extinctions per year which could make it the single biggest extinction event since the extinction of the dinosaurs. So many believe that we need to preserve life on this planet, even if it means bringing back long since dead species. In order to conserve biodiversity.

How is it done?:
There are two main methods of de-extinction; cloning and selective breeding. Cloning is the main method of conducting de-extinction, it involves the process of using dna from hair, skin, nail, tooth or horn samples and using a closely related species as a surrogate parent. Such as a band-tailed pigeon for the now extinct carrier pigeon or an asian elephant for the wooly mammoth. Though cloning requires a living cell, genome editing is a process which is being thoroughly researched and considered by many as the only way to bring back long dead species. This is when the genome of a living species is edited to have the characteristics of the desired species, like editing the genome of a elephant in order for it to grow a thick coat of hair and to continue doing this until the genome is identical to that of a wooly mammoth. The other proposed method of conducting de-extinction is through the use of selective breeding. This would involve researchers to compare the dna of the extinct species to that of a species that still carries the extinct species genes. This method has been used to resurrect the Quagga; a subspecies of zebra which have been extinct since 1883. The last pyrenean ibex dies in captivity in 1999, a few months before hand a group of scientists extracted tissue samples from her ear. They attempted to bring the species back after her death but due to the tissue being of an old sample (13 years) the dna was older and as a result any offspring would have a diminished life. They removed nuclei of an egg from a related species and artificially inseminated it. They attempted this hundreds of times with only two samples living past two months of gestations and only one being born. Which died only a few minutes after its birth due to a lung defect which is common in cloned animals (dolly the sheep had a similar defect). Though the problem that there would not be any males of the species and so would die out anyhow. It was suggested that one of the X chromosomes would be taken out and replaced with the Y from another species. Though this would not be a pure pyrenean ibex even though the technology does not exist at this point in time.

Opposition to De-Extinction:
A common opposition to de-extinction is that the time, funding and people that work towards the resurrection of extinct species would be better off going towards preserving endangered species who are at risk of going extinct, taking preemptive measures to preserve life as we know it instead of waiting till it is too late and then discussing whether or not to bring it back. The Scientific American, a very well known and respected scientific journal printed an editorial which stated that such technologies would be best used to preserve modern biodiversity rather than bring back a species from the grave. Though this rings true for many there should also be effort, time and resources devoted to bringing back species that went extinct due the human race whether is be a direct result of being hunted to death like the thylacine/tasmanian tiger or the carrier pigeon or if it was made extinct due to the expansion of humankind such as deforestation or global warming as a result of our industrial growth. Another more scientific opposition of de-extinction is that though the species that have been brought back to life that does not mean that they will act the same as they did before they became extinct, due to the surrogate parents acting different and so they might not hunt or eat a species that they did before. There is also the school of thought that looks at our past attempts at introducing a new species to an ecosystem such as the introduction of the cane toad to Australia and the disastrous effect that has had on the local and indigenous species. Though there is counter argument that they would not be ‘new’ this is untrue due to the changes that the world has seen for example the heating up of the world so some of the ecosystems that the wooly mammoth used to inhabit has changed. The re-introduction of the tasmanian tiger may drive many indigenous species to extinction due to the strain that the cane toad infestation has put of their population.