Entrepreneur plans to resurrect woolly mammoths

Over the last 800,000 years the woolly mammoth was a significant part of the Arctic ecosystem, roaming the grasslands of what are now North America, Russia and Europe before going extinct 4,000 years ago. 

If Ben Lamm and George Church have their way, these are scenes we may see again.

The pair have co-founded a new de-extinction company called Colossal, aiming to use the latest genetic engineering technology to resurrect long-dead animals before returning them to the wild. Millions of pounds have already been pledged by funders.

'Never before has humanity been able to harness the power of this technology to rebuild ecosystems, heal our Earth and preserve its future through the repopulation of extinct animals,' says Lamm in a press release.

'In addition to bringing back ancient extinct species like the woolly mammoth, we will be able to leverage our technologies to help preserve critically endangered species that are on the verge of extinction and restore animals where humankind had a hand in their demise.'

The poster child for this ambitious experiment is the woolly mammoth. Church has been creating his own lab to tweak the genetic code of their closest living relative, the Asian elephant, to make a hybrid animal that would survive in the Arctic Circle.

Genes need to be added to elephant DNA to produce a thick and shaggy coat, long and curving tusks, smaller ears and subcutaneous fat stores.

Technically this would not produce an actual woolly mammoth but a genetically engineered hybrid. It is thought that, along with a handful of other genes, these extra pieces of information will allow the animal to survive in the Arctic Circle and take the place of the long-extinct mammoths.

It's a gigantic challenge for science and poses an ethical conundrum: is it fair to bring an extinct species back thousands of years after its demise? And what impact would a mammoth have on a modern environment?

Dr Victoria Herridge is a researcher at the Museum who studies ancient elephants. She is well aware of the big hurdles the Colossal team face.

She says, 'There are a lot of questions raised by this project. The key ethical points are the aspects of animal experimentation and husbandry - what is this creature? Is it a new species? How many do you need?

'Then if they succeed, what will the needs be of an intelligent social creature? And what are our obligations to it?'

Is it ethical to bring mammoths back to life?

There are two ways we could bring extinct animals back to life.

The first is cloning, which is how Dolly the sheep was created. Scientists take the DNA from the cell of one individual, insert it into a fertilised donor egg and place the egg into a surrogate mother.

This method has already been used to bring an extinct animal back from the dead, the little-known Pyrenean ibex, or bucardo. A subspecies of the Iberian ibex, it was declared extinct in 2000. Three years later, the DNA from frozen bucardo skin samples were cloned and placed in a surrogate domestic goat. The resulting kid was the first time an extinct animal had ever been brought back to life.

The success was short-lived. The animal only survived for seven minutes, giving it the regrettable record of the being only animal to have gone extinct twice.    

Despite numerous whole mammoth carcasses having been dug up in the Siberian permafrost (sometimes so fresh they are red when excavated), the process of deep-freezing shatters animal cells and degrades DNA. While this has allowed scientists to piece together the mammoth genome, to date no one has been able to retrieve an entire mammoth genome as it would have been in life.

This is where the second method of resurrecting extinct animals comes in. It involves narrowing down the specific individual genes of the mammoth which allowed them to survive in the high Arctic, then inserting these into the genome of its closest living relative, the Asian elephant.

The idea is to utilise the powerful gene editing technique known as CRISPR (clustered regularly interspaced short palindromic repeats), which allows for highly targeted genetic changes.

The modified genome is implanted into a fertilised elephant egg, and then into a surrogate elephant. The result would be a mammoth-elephant hybrid.

Victoria says, 'At that point you have to start asking questions about the ethics of experimentation on elephants. You won't know whether or not there is an issue with your chimeric creature until further down the line.'

In response to these concerns, artificial wombs have been suggested. This has been achieved before with lambs, but there are still big limitations with this novel technology.

'My understanding of the artificial womb technologies is that it would still require a period of implantation in a surrogate mother,' says Victoria. 'As yet, I don't think it is possible to use a biobag it for the entirety of the process, from fertilisation to being born.

'There are also varying success levels, no way is this method 100% successful.'

In addition, elephants do not thrive in captivity. They are known to do poorly in zoos and there is now a growing movement to phase them out of zoos entirely. What responsibility do we have to all elephants under the care of humans?

There are also countless unknowns. Do we know enough about elephant biology to predict what parts of the genome need to be tweaked to allow them to survive in the Arctic? Hair and fat are obvious fixes, but what about other sorts of biochemical needs we might not yet be aware of? 

Can mammoths really reverse climate change?

So why try to resurrect the mammoth in the first place?

Colossal say that they want to 'rewild extinct species to their original habitats so they can revitalize lost ecosystems for a healthier planet'.

It is claimed that woolly mammoths will help to fight climate change by restoring the vast grassland steppes which once encircled the Arctic pole but which changed to forest when the mammoth went extinct. 

'One of the benefits of grasslands over tundra or forests in the high Arctic is they are really good carbon sinks,' explains Victoria. 'During the summer months the grasses grow high before dying back in the winter. But because of the cold temperature, they don't degrade. Every season's growth is stored in the ground. That is why the permafrost is a massive carbon sink.'

Additionally, forests and shrubland are typically much darker in colour compared to grasslands, meaning that they absorb more heat from the Sun helping to warm the planet. This is compounded by the fact that snow cover is greater in areas of grassland, which again helps to reflect the Sun's rays off the planet.

Finally, it is thought that the presence of huge numbers of large animals tramping over these grasslands would have compacted the snow, making it last for longer and insulating the ground which in turn maintained the permafrost. It is argued that this would help to prevent methane emissions from being released by seasonal thawing due to global warming.

It is argued that the giant herbivores such as mammoths maintained these open grasslands by keeping encroaching forests at bay, and as a result helped cool the planet.

But this is not an opinion shared by everyone in the field.

Professor Adrian Lister is a researcher at the Museum whose work has focused on the extinction of the mammoth in relation to both people and the environment. 

'The idea that the forests and tundra only expanded across the entire northern hemisphere because megafauna went extinct is patently false,' says Adrian. 'Modelling shows that climate change alone accounts for it.

'That is not to deny that megafauna can have an impact on local vegetation, as we know from modern examples, but it would presumably take huge herds of "mammoths" to do this again, and we shouldn't kid ourselves that we are smart enough to predict all the possible unintended side effects.'

Oone more question remains to be answered: just how many mammoths would it take to change the Arctic? There were once perhaps hundreds of thousands of mammoths roaming the northern grasslands during the last ice age.

The impacts of this work will be far-reaching and significant.