De-extinction involves bringing back species that have disappeared from Earth. For the woolly mammoth, this process does not involve traditional cloning. Instead, scientists aim to create a genetically-engineered hybrid animal possessing the functional and visual characteristics of a woolly mammoth. Several scientific organizations are actively working towards this goal, pushing the boundaries of genetic engineering and reproductive technologies.
The Scientific Approach to Revival
Scientists begin the de-extinction process by recovering and sequencing fragmented ancient DNA from woolly mammoth remains. These remains are often found preserved in Arctic permafrost. Recent breakthroughs have allowed for the recovery of 3D chromosome structures from 52,000-year-old mammoth skin, providing more complete genetic information. This ancient DNA, though often degraded, provides the blueprint for desired mammoth traits.
The closest living relative to the woolly mammoth is the Asian elephant, sharing approximately 99.6% of its DNA. Scientists utilize gene-editing technologies, specifically CRISPR, to insert selected mammoth genes into the Asian elephant genome. These genes encode for distinct mammoth traits such as a shaggy coat, fat deposits for cold resistance, small ears, and curved tusks. The outcome of this genetic modification is a hybrid creature.
Once a viable hybrid embryo is developed through gene editing, two primary methods are considered for gestation. One approach involves implanting the embryo into a female Asian elephant, which would serve as a surrogate mother for the approximately 22-month pregnancy. This method presents challenges due to the long gestation period and concerns for the welfare of the endangered Asian elephant. The alternative is an artificial womb, which could bypass the need for elephant surrogates, though this technology is still early for large mammals.
Ecological Arguments for Bringing Back Mammoths
A primary justification for woolly mammoth de-extinction centers on the proposed restoration of the “mammoth steppe” ecosystem. This vast grassland, which once extended across the Arctic during the Pleistocene epoch, supported abundant grazing herds including mammoths, bison, and horses. The disappearance of these large herbivores led to the transformation of the landscape into the moss and shrub-dominated tundra seen today. Reintroducing mammoth-like creatures could help convert the tundra back into a more productive grassland ecosystem.
The theory suggests that large herbivores can act as “eco-engineers” to reshape the Arctic environment. By grazing and trampling vegetation, they could suppress the growth of trees and shrubs, allowing grasses to flourish. Their movement and digging through snow in winter would also compact the snow cover, reducing its insulating effect and allowing colder temperatures to penetrate deeper into the soil. This deeper freezing of the ground could help protect the permafrost from thawing.
Preventing permafrost thaw is a key environmental benefit. Permafrost contains immense amounts of trapped organic carbon; as it thaws, microbes convert this matter into potent greenhouse gases like carbon dioxide and methane, contributing to global warming. Restoring grassland ecosystems, which reflect more solar energy due to less dark vegetation (the albedo effect) and store more carbon in their deep root systems, could mitigate these emissions. Projects like Pleistocene Park in Siberia are already experimenting with reintroducing grazers to demonstrate this ecological transformation.
Ethical and Practical Concerns
The welfare of the engineered hybrid animals raises ethical questions. A mammoth-elephant hybrid would be born without a biological mother of its own kind to provide social learning and teach species-specific behaviors. Woolly mammoths were social creatures, and their complex social structures would be absent for a resurrected individual, potentially leading to behavioral difficulties. There are also welfare considerations for the endangered Asian elephant surrogates, which would endure a long 22-month pregnancy with a genetically modified embryo, potentially facing health complications or failed pregnancies.
Reintroducing a species that has been absent for thousands of years also carries the risk of unintended ecological consequences. The modern Arctic ecosystem has evolved in the absence of mammoths, and introducing a new megaherbivore could disrupt existing food webs and habitats in unpredictable ways. There is a possibility that these hybrids could introduce new diseases to current wildlife populations or compete with native species for resources, potentially leading to declines in existing populations. Predicting the long-term impact on a changed environment remains a complex challenge.
Beyond the biological and ecological concerns, there are practical and financial hurdles to overcome. Creating a viable, self-sustaining population would require raising not just a few individuals, but potentially hundreds of thousands of animals to have a noticeable ecological impact. The current Arctic landscape is vastly different from the mammoth steppe, raising questions about where these animals would live and who would manage and protect them. Critics also question whether the financial investment in de-extinction projects could be more effectively allocated to conserving existing endangered species and their habitats, which face immediate threats.