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De-extinction – five species that may be “brought back to life”

In this article, Inside Ecology takes a look at five species that are the focus of de-extinction efforts…

The concept of de-extinction has been gathering pace in recent years. The idea that we can bring species back to life, both tantalises and horrifies people in equal measure. However, de-extinction isn’t so much about resurrecting species in their original form, it is more about using technology, such as gene editing and selective breeding, to create an animal that has the desirable features of the extinct animal.

Why would you want to bring back certain species? It’s a good question and one that has rather complex answers. The main argument is associated with the idea of rewilding – focusing on bringing back “keystone” species that maintained balance within ecosystems; or at least bringing back the key traits of those species within a living animal.

The moral, ethical, cultural and legal arguments for de-extinction rage on and are not the focus of this article. Rather, what follows is a list of five species that scientists and others are looking at “bringing back to life”.

Woolly mammoth
Surely, this animal needs no introduction. Star of screen and imagination, the woolly mammoth fascinates the human mind. It last walked the earth around 4,000 years ago and has become the poster image for the last ice age. Efforts are already underway to return the mammoth to parts of its former range, in the hope that it will help combat climate change and bring ecosystem stability.

Gene editing techniques allow for the splicing of mammoth DNA into the DNA of the woolly mammoth’s closest living relative: the Asian elephant. The outcome would be part elephant, with the additions of a shaggy coat, smaller ears and blood that is adapted to the cold.  A team of Harvard scientists are now working on developing a hybrid embryo, which means that in the not too distant future, the “mammophant” could be brought to life.

Birds of New York (New York State Museum. Memoir 12), Albany: University of the State of New York. Plates by Fuertes later reproduced in Birds of America (1917?) by Thomas Gilbert Pearson (1873-1943) et al. (Source: Wikimedia Commons)

Passenger pigeon
If the woolly mammoth is the poster image for the ice age, the passenger pigeon could arguably be seen to represent de-extinction efforts. Once considered to be the most abundant bird in North America the passenger pigeon was hunted to extinction in their millions. The pigeons travelled in gigantic flocks, making them easy targets for hunters. The last known passenger pigeon died in 1914 in Cincinnati Zoo.

Revive & Restore have been working on editing the genome of the band-tailed pigeon and are working towards hatching the first generation of passenger pigeons in 2022, with trial releases following on from that.

Unknown photographer, 1933

The thylacine, also known as the Tasmanian tiger, has been extinct for 80 years. In common with the passenger pigeon, the last of these animals died in captivity.

The marsupial is proving tricky to revive, as unlike the woolly mammoth and passenger pigeon, there aren’t any living relatives that closely resemble the thylacine. The closest is the numbat or banded anteater – a native to Western Australia. At present, the technology for recreating the Tasmanian tiger isn’t quite there. However, researchers from the University of Melbourne envisage that the woolly mammoth project will play a major role in advancing the science, which means that thylacine may one day roam their former range.

Plate 22 (Spanish Tur) from the book ‘Wild oxen, sheep & goats of all lands, living and extinct’ (1898) by Richard Lydekker. From a sketch by Joseph Wolf in the possession of Lady Brooke. The ram in the foreground was killed in the Val d’Arras. (Source: Wikimedia Commons)

Pyrenean Ibex
The Pyrenean ibex, or bucardo, was a wild goat and sub-species of the Iberian ibex. As the name suggests, the ibex was native to the Pyrenees. The species became extinct relatively recently – in the year 2000 – although the exact cause(s) of its demise remains unclear.

Since its extinction, scientists have worked to bring the Pyrenean ibex back to life through cloning. A successful clone was brought about in 2009, making it the first species to become “un-extinct”; however, the ibex died soon after birth from lung problems.


Quagga mare at London Zoo, 1870 (Source: Wikimedia Commons)

The quagga was a sub-species of the plains zebra. It differed from other zebras by having stripes on the head, neck and front portion of its body only, and brown colouring over the rear of its body. The reduction in striping has been explained as a possible adaptation to living amongst open-country habitat. The quagga was another victim of hunting and the last known animal died in Amsterdam Zoo in 1883.

The journey to restore this species to the African plains began in the late 1960’s with Reinhold Rau. Research revealed that the quagga comprised a colour variant of the plains zebra, which meant that there was the possibility for quaggas to be reinstated through selective breeding. The Quagga Project has been doing just that, estimating that four generations of selection will be sufficient to demonstrate the feasibility of selective breeding in restoring the quagga phenotype.

Header Image: ‘Tasmanian “Zebra Wolf”‘ Thylacinus in Washington D.C. National Zoo. This photo is of a pair of Thylacines, a male and female, received from Dr. Goding in 1902. (Source: Wikimedia Commons).

About the Author: Kate Priestman (CEnv, MCIEEM), Co-Founder and Editor of Inside Ecology, has over sixteen years experience as an ecologist.  Prior to setting up her own consultancy business in 2012, Kate worked in London for over a decade, providing the lead ecology role for a number of high profile projects.  In addition to running Inside Ecology, Kate works as a freelance writer and artist.