Could woolly mammoths come back to life?
Jurassic Park made it look so easy. According to the book and film, all scientists needed to do was extract dinosaur blood from mosquitos preserved in amber. They could then rebuild the genomes or genetic imprints of the extinct creatures, with frog DNA used to fill in any gaps. All of a sudden, you had every dinosaur species brought back to life as the attraction of a theme park.
So why has this not happened for real, especially in an age where scientists have cloned sheep, or in the UAE, camels? The simple answer is that Jurassic Park does not reflect what we know about cloning. Dinosaur bones are millions of years old and only fragments of DNA remain.
The chances of bringing back woolly mammoths are not quite so remote, however. The species died out less than 4,000 years ago and preserved carcasses are discovered fairly regularly. As snow in the Arctic tundra of Siberia has decreased over the years, it has unearthed a number of specimens. In 2007, a six-month-old female calf was found, and in 2011 a thigh bone with the marrow still intact. Then in 2013 came an example dating back 40,000 years, with most of its body, head and three legs present. Best of all it was still oozing blood, whereas previous finds held only a few specks. So unlike dinosaurs, which went extinct 65 million years ago, mammoth carcasses and blood do exist – hence the repeated interest in whether the species could be revived.
Here’s why it hasn’t happened yet. In cloning terms, and in the examples of Dolly the sheep or Injaz the camel, both involved cells taken from another animal, injected into the egg of a surrogate mother from the same species, with the resulting embryo implanted back in the womb. The DNA of the offspring was therefore a copy of the animal it was taken from, rather than biological parents.
In order to clone a mammoth in this way, cells with a complete genome sequence, with all of the DNA intact, would be required, as well as a suitable animal to act as the surrogate – mammoth cells plus a female woolly mammoth.
Apart from the obvious lack of a mammoth surrogate, the other problem facing scientists is that DNA deteriorates over time, so a complete copy of the animal’s genome sequence has yet to be found.
But given what we do know, creating some kind of hybrid is still possible. Last year, a team at Harvard University successfully spliced mammoth DNA into the genome sequence of an Asian elephant – meaning that, in theory, a version of that animal could be born with some resemblance to a woolly mammoth, with a female elephant as the surrogate.
The mammoth’s genome sequence is understood enough to know what gave the creature some of its distinct physical attributes – its small ears designed to lose less heat; its thick, hairy overcoat for withstanding brutal temperatures; its chunky layers of fat also for insulation, and its blood cells designed to transport oxygen more effectively in the cold.
The Harvard team also noted that, despite these unique features, 99.4 percent of the genome was similar to that of an elephant’s. By swapping just 14 genes, they created the cells of a potential mammoth substitute.
The Harvard team found that 99.4 percent of the mammoth genome sequence was similar to that of an elephant
This seems the closest we will get to a clone for now, although the dream is not quite over. The North-Eastern Federal University in Yakutsk, Siberia, in partnership with scientists in South Korea, hopes to decipher the mammoth’s complete DNA structure by 2017. The plan is to then culture the live cells, create a clone and also artificial living cells based on artificial nucleus DNA.
Writing for The Observer in 2015, however, biologist Beth Shapiro questioned the notion of bringing species back to life. Assuming that an Asian elephant could give birth to a hybrid, the modern world is not its natural environment, and it would most likely be bred and live its days in captivity. Her point: we need to look beyond the scientific challenges.
So we can’t yet clone an authentic mammoth. Creating an elephant that looks like one perhaps, but with a lot of work needed to make it a success. A shame really, as Mammoth Park sounds just the sort of attraction that would get the green light here in Dubai.