Scientists believe that between 30 and 159 species go extinct every single day. Human activity is responsible for much of this and some even claim that we are experiencing a global mass extinction event. But as we say goodbye to some of the most wonderful species to ever grace the Earth, is it possible to reverse the trend and bring back what has been lost?
There are three methods that scientists are looking into to reverse extinction. The first is known as back breeding. By taking animals with similar characteristics to the extinct species and selectively breeding them, traits and appearance of previous species can be brought back. This is already being used to bring back aurochs, which was a relative of modern-day cattle, and went extinct in 1627. However, no amount of selective breeding can truly bring a species back. Only certain features of animals could be bred, and ultimately, these would not be the same as lost species.
The second method is genetic engineering. Scientists could line up the genome of an extinct animal with a genome from a close living relative. The genes can then be edited to produce characteristics of the extinct species. It could then be grown in a surrogate. As with back breeding, the end product would not be an exact species but rather a hybrid of the two animals that the genetic code was taken from. This method is being explored for mammoth and passenger pigeon reproduction.
The third option is to produce a clone. By taking a cell from a living or recently deceased animal, extracting the nucleus (the brain of the cell) which contains DNA and implanting the nucleus into an egg cell of a close relative, a genetically identical offspring would be produced. This method has already been used to clone living animals like sheep. However, it requires non-degraded cells and species that have been dead for years are unlikely to provide this.
Will We Ever See Dinosaurs Walking the Earth Again?
As much as I would love to see a tyrannosaurus rex rampaging through the countryside, it is unlikely that scientists will ever be able to reproduce them. As they died out millions of years ago, back breeding is not a viable option, with no modern day species a close enough match, and no DNA has been found for genetic engineering or cloning. Scientists have tried the “Jurassic Park” method of taking DNA from blood in mosquitoes that have been preserved in tree resin, although they have been unsuccessful. Species that have gone extinct over the past few thousand years are better candidates.
Why Should We Bring Species Back?
There are many arguments as to why we should bring species back. To bring back a wooly mammoth and have a breeding population would be one of the great achievements of mankind (although humans played a big part in their extinction in the first place). However, I wouldn’t like to think that we breed animals just to put in a zoo for human entertainment. I would much rather see a thriving ecosystem with a number of different species co-existing. Keeping the ecosystem under control could be a major problem. Rapid population growth or overly effective predatory species could end destroying food chains in some areas, and repopulating areas with previously extinct animals would have to be closely monitored.
With rapid developments in science, it is possible that scientists will be cloning mammoths by the middle of the next decade. The question is not if we can do it, but rather when can we do it.