CRISPR and The Woolly Mammoth – A 21st Century Genetic Renaissance

The Woolly Mammoth, an illustrious symbol of anthropogenic extinction

BY Ben Lamm

Over 99% of the 4 billion species that have ever lived are now extinct in part from human activity (1), and the woolly mammoth, once larger than life itself, blends in among the countless, anonymous victims (2). Weighing up to 6 metric tons and towering over 11 feet tall, Mammuthus primigenius guilelessly roamed the Earth for 100,000 years until its extinction a mere 4,000 years go. Evolved from contemporary Asian elephants, it was a feat of genetic design. Armored with Arctic-adapted insulating fat and fur and cold-resistant blood, the woolly mammoth evolved high crowned teeth to chew on silica-rich grasses (3) while breaking down shrubs and trees. In so doing, it enabled expansive grasslands to flourish, indirectly boosting the expansion and diversification of life – having earned a spot as a keystone species to the Arctic ecosystem. 

In the Pleistocene era commonly known as the Ice Age, spanning 2.6 million years ago to about 12,000 years ago, Arctic ice sheets reached as far south as Chicago and the British midlands. Alongside woolly mammoths, herbivorous megafauna, including horses, bison, reindeer and elk, roamed and grazed on Arctic permafrost-blanketing grasslands, critically contributing to the complex biochemical dance of their natural ecosystems. However, coincident with waves of human migration at the end of the last Ice Age 30 to 10,000 years ago, the spread of human activity and hunting precipitated the extinction of nearly 80% of these large megafaunal species (2,4). The loss of these key functional species, woolly mammoth included, impoverished biodiversity and weakened Arctic ecosystems – blunting their biochemical roles at a global scale. 

De-extinction: A 6-point case for the woolly mammoth

A boost to biodiversity. All but a luxury in light of rapid species and habitat loss, reinstating the woolly mammoth has the potential to reinvigorate its native Arctic habitat and boost associated biodiversity (5). In a graph representing the web of life, the woolly mammoth formed a particularly well-connected hub, the reintroduction of which will lead to a massive reorganization of the graph – eventually rebalancing entire ecosystem dynamics in fundamentally qualitative ways. 

A clamp on climate change. Symbiotic to a biodiversity boost, reintroducing the woolly mammoth will curb climate change by helping rewild the Arctic (6). Trampling trees, woolly mammoths will roll out the red carpet for grasslands to flourish across the Arctic tundra, recreating the aptly named “mammoth steppe”. Sequestering carbon in their roots and forming a smooth surface reflecting hot sunrays, grasslands will help minimize global warming. In parallel, a thinner, trampled-on permafrost layer will be less insulated from the cold Arctic air, staying cooler longer and preventing the release of its over 1,500 gigatons of stored carbon (nearly twice that present in the Earth’s atmosphere). 

A scalable strategy. Ecological engineering through the reintroduction of a keystone species is more scalable than many other biodiversity conservation programs. While many Sisyphean attempts at preserving species such as the Northern white rhinoceros or Hawaiian Kiwikiu bird through labor and capital-intensive programs have remained slow and inefficient, the introduction of the woolly mammoth into contemporary Arctic ecosystems is scalable. First, creating a genetic blueprint for a keystone species to reintroduce into a globally crucial host ecosystem enables the design, creation, and regeneration of life ad infinitum. Second, megafaunal populations spontaneously and rapidly grow by virtue of their reliance on intrinsic, non-human biotic processes (7) – sustainably and at scale (8).

A moral decency. Given that we are well-equipped with the technology requisite to do so safely, would it not be amoral not to reinstate a species which we have directly led to the extinction of (9)? A cold period of resistance to in vitro fertilization eventually thawed as it now represents a widespread reproductive tool – crises mothering invention, as climatic conditions continue to degrade around the world, any similar questioning of de-extinction will likely fade as we scramble for solutions in a desperate, ethically informed game of catch-up. 

A nectar of knowledge. De-extinction efforts on behalf of herbivorous megafauna such as the woolly mammoth will advance technological and ecological knowledge and further our understanding of conservation initiatives (10). Inevitably, this will sharpen our dynamic, heuristic understanding of fields spanning all evolution-, biology, and ecology-centric disciplines. 

An elegant endeavor. Woolly mammoth de-extinction has an increasingly low sactivation energy: in short, it’s doable. Galvanized by our exponentially growing knowledge of genetic engineering, alongside the accessibility of the Asian elephant (11,12) (notwithstanding the challenges of scavenging for old woolly mammoth bones and the extraction of fragmented, contaminated DNA (13)), the reconstitution of the woolly mammoth genome has never had such a low cost-benefit ratio.  

Genetic ingenuity for regenesis

Capitalizing on the cut and paste mechanism of an ancient bacterial immune system used to genetically disarm invading pathogens, CRISPR (clustered interspersed short palindromic repeats) can now be readily harnessed to edit cross-species genomes (14). Provided a close genetic relative, the genomic regions that evolved to give rise to the new species can be identified, allowing to edit these back into the original genome to generate the new genome. Having diverged only 4 million years ago, the Asian elephant, which is 99.6% genetically similar to the woolly mammoth (15), provides the ideal template for the latter’s reconstruction. Experimentally, bringing back the mammoth thus now simply relies on reverse genetic engineering of Asian elephant-evolved traits to bridge evolutionary gaps, such as those underpinning the advent of greater fat stores, thicker hair, and cold-efficient blood – after which nature takes over as this new genetic blueprint gives way to the beautiful, multicellular, hierarchical dance of development. 

Life 3.0 – an optimistic outlook

Bringing back the woolly mammoth is one of the most elegant and organic solutions yet to climate change – creating life to preserve Life. As the Spanish philosopher Spinoza has been credited to say, “man is not a separate empire within an empire”, as we are entirely embedded in and constantly contributing to the biochemical web we were born from and will dissolve back into. The anthropogenic de-extinction of key species in this web of life is quintessential Life 3.0 in action (16) – life redesigning its own hardware for recursive intra- and inter-species self-improvement. The groundwork is laid to now capitalize on this most fantastic human capacity by giving life back to that which was, indeed, once larger than life. 

 

References

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  3. Shapiro B. How to Clone a Mammoth. How to Clone a Mammoth. 2015. 
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  12. Dastjerdi A, Robert C, Watson M. Low coverage sequencing of two Asian elephant (Elephas maximus) genomes. Gigascience. 2014; 
  13. How to clone a mammoth: the science of de-extinction. Choice Rev Online. 2015; 
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