Planet Care

94: De-extinction


According to the IUCN Red List of Threatened Species, there are now 41,415 species on the IUCN Red List, and 16,306 of them are endangered species threatened with extinction.

An estimated 50,000-70,000 plant species are used in traditional and modern medicine worldwide.

About 110 million tons (100 tonnes) tons of aquatic organisms, including fish, molluscs and crustaceans are taken from the wild every year and represent a vital contribution to world food security.

It is called the Sixth Extinction.


De-extinction aka resurrection biology

A paper published in the journal Proceedings of the National Academy of Science reported the Earth BioGenome project where the DNA of all known eukaryotic life on Earth is being recorded. It is estimated to take 10 years, cost US$4.7 billion, and require more than 200 petabytes of digital storage space (a petabyte is one quadrillion, or 1015 bytes).

“Eukaryotes” refers to all plants, animals, and single-celled organisms, all living things except bacteria and archaea (those will be taken care of by the Earth Microbiome Project). It is estimated there are somewhere between 10–15 million eukaryotic species, from a rhinoceros to a chinchilla down to a flea (and there are far smaller still).

Of the 2.3 million of these documented so far, scientists have sequenced fewer than 15,000 of their genomes (most of which have been microbes). One of the biggest questions is how, exactly, scientists will go about the gargantuan task of collecting intact DNA samples from every known species on Earth. Some museum specimens will be used, but many have not been preserved in such a way that the DNA could produce a high-quality genome. One important source of samples will be the Global Genome Biodiversity Network.

There is significant controversy over de-extinction or resurrection biology, or species revivalism. Critics assert that efforts would be better spent conserving existing species, that the habitat necessary for formerly extinct species to survive is too limited to warrant de-extinction, and that the evolutionary conservation benefits of these operations are questionable.

In 2017, a report published in the journal Nature Ecology & Evolution, found that de-extinction of extinct animals for the species in New Zealand and New South Wales, Australia would be harmful to biodiversity. The lead author of research is the professor of biology at the Carleton University, Canada, Joseph R. Bennett, who used the extant analog to predict the result of the de-extinction of extinct animals with his six colleagues from Australia and New Zealand.

Indeed Michael Crichton’s best-selling dystopian novel “Jurassic Park” (1990) and Steven Spielberg’s blockbuster film of the same name (grossing USUS$1 billion) have led people to believe that cloning dinosaurs back to life could only go terribly wrong. But there are an increasing number of cases where species might be “brought back to life”.

Cloning involves extracting the nucleus from a preserved cell from the extinct species and swapping it into an egg of the nearest living relative. This egg can then be inserted into a relative host. It is important to note that this method can only be used when a preserved cell is available. This means that it is most feasible for recently extinct species.

For example, the banteng is an endangered species that was successfully cloned, and the first to survive for more than a week (the first was a gaur that died two days after being born). Scientists at Advanced Cell Technology in Worcester, Massachusetts, United States extracted DNA from banteng cells kept in the San Diego Zoo’s “Frozen Zoo” facility, and transferred it into eggs from domestic cattle, a process called somatic cell nuclear transfer.

In The Embryo Project, Thirty hybrid embryos were created and sent to Trans Ova Genetics, which implanted the fertilized eggs in domestic cattle. Two were carried to term and delivered by Caesarian section. The first hybrid was born on April 1, 2003, and the second two days later. The second was euthanized, but the first survived and, as of September 2006, remained in good health at the San Diego Zoo.

What you can do: Donate to organisations working to prevent the extinction of threatened species.

Discover Solution 95: CRISPR via DNA


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