Bringing back an extinct creature like the woolly mammoth seems more like science fiction than reality. Unfortunately, we will never be able to bring back a mammoth from thousands of years ago, but work is being done to make a hybrid elephant-mammoth.
Can we clone a mammoth like we did with Dolly the sheep?
DNA, the ‘blueprint of life’ holds the instructions to make living things.
By transferring the genome (all of the DNA) of any cell from your favourite animal and into an egg cell, you can make a clone. This is how Dolly the sheep was made: the DNA from an udder cell of the sheep to be cloned was transferred into another sheep’s egg cell and grown in a surrogate. In theory, we could do this with animals that are extinct. The problem is that the DNA has to be in perfect condition, so mammoth DNA (which is over 4000 years old) is not ideal.
Professor Love Dalen from the Swedish Museum of Natural History, explains how from both his and his colleague’s “results unanimously show that the genomes in these samples are degraded into many tens of millions of fragments. And there is no way to put these back together (in the right order). This means that it in all likelihood is impossible to find a cell with intact chromosomes. In other words, classic cloning is out of the question.”
How else can you revive a woolly mammoth? An alternative the ‘classic cloning’ is to use the genome of a related species as a template and change it until it matches your favourite animal. This is what Professor George Church’s group is doing at Harvard University. They are using a gene editing tool called CRISPR to cut and paste mammoth bits of DNA into an Asian elephant’s genome. So far, they have made 45 edits to make the elephant DNA more ‘mammothy’ but in the end, they are aiming for an elephant-mammoth hybrid, rather than a ‘true’ mammoth. There are a few reasons why a ‘true’ mammoth can’t be revived. For one, we can’t be sure we have the complete mammoth genome because we only have small, old pieces of mammoth DNA. Biologist Dr Patrícia Pecnerova points out that “working with degraded mammoth DNA, which is only found in small pieces, requires that it is aligned against a reference genome - and for this elephant genome is used - so anything which is not similar enough or found in the elephant genome, is lost”. Even if we did have perfect DNA, there are other factors that we might have missed. Geneticist Dr Richard Edwards explains: “As well as genetics, there are non-genetic factors that are passed on from mother (and sometimes father) to child during fertilisation and development, and we simply don't know what effects they would have on development.”
How would the mammoth be born? Whilst the Church lab have made progress with creating a mammoth genome from an elephant one, the next big hurdle will be going from genome to baby mammoth. If we think back to Dolly the sheep, the genome was first put into a sheep egg cell, and then that egg was put into a surrogate sheep so Dolly could grow and be born. The closest living relative to the woolly mammoth is the Asian elephant. As these are endangered, using one as a surrogate would be ethically dubious. Professor Church has other plans. He hopes to grow a mammoth in the lab, no elephants involved. This is what happens in Jurassic park, with a lab full of dinosaur eggs. Unfortunately, mammoths grow in the womb (like us) and currently artificial wombs are still closer to science fiction than reality.
Takeaway: Mammoths cannot be brought back to life at present. Progress is being made to create an elephant-mammoth hybrid but overcoming the obstacles to growing the mammoth without an elephant surrogate could take many years.