You may be aware that there are currently growing efforts to clone long-extinct animals such as mammoths, which would be sure to put a smile on John Hammond’s face. There is a growing consensus in the scientific community that we should use similar technology to resurrect recently extinct animals. There are a number of criteria a species must fit into, in order to be selected as a potential candidate, including preservation of viable genetic material and the existence of suitable habitat for reintroduction. We are not talking about a mosquito in amber here; instead, the species for which such a project could be viable are those that have become extinct within the past 100 years. There may be potential along the way to learn more about developmental processes, which may help to inform future medicine. Two examples from Australia highlight the current efforts to resurrect a previously lost species.
As an Amphibian Biologist, I could not help but pick this first example – the gastric brooding frog (Rheobatrachus spp.). There were two closely related species that were discovered in the latter half of the 20th century, shortly before they became extinct. They acquired their name from the unusual behaviour exhibited by the females incubating their eggs: they would swallow the fertilised eggs and convert their stomach into a frog nursery, before regurgitating fully-formed froglets approximately six weeks later. During this time, the mother shuts down all function of her stomach and does not eat until her brood have developed. In 2013, scientists in Australia successfully created a living embryo from preserved genetic material, with the next goal being the production of an embryo that can survive to the tadpole stage.The second species is the Thylacine or Tasmanian tiger (Thylacinus cynocephalus), which was a marsupial predator hunted to extinction by mankind. They were already on the way out before a bounty was put on their head, but it certainly did not help things! The Australian Museum in Sydney began a cloning project in 1999 with efforts still ongoing, using ethanol-fixed tissue from a handful of specimens. There are deep ethical questions that need to be addressed with such projects, but hopefully one day passenger pigeons will fill the skies once again, and species extinction will be a thing of the past. If we have the means to restore a species, especially one that disappeared due to our direct actions, surely we have an obligation to do so.
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