The Colossal Mission

De-Extinction of Woolly Mammoths and Its Potential for Ecological Renewal

By: Matt Kraemer

Photo above by Beth Zaiken

In 1996, cloning went from science fiction to reality. Dolly the sheep, the first mammal cloned from an adult somatic cell, bypassed the need for sperm and egg fusion. This groundbreaking achievement shattered the boundaries of biology and expanded our understanding of life itself. This revelation stunned the world and emboldened scientists to explore the vast potential of cloning, raising profound questions about its potential for species revival, genetic modification, and conservation.

With cloning mammals now a reality, scientists have eagerly pursued even more ambitious endeavors. Whether it’s reviving the woolly mammoth to restore the prehistoric ecosystem of the "Northern Serengeti" at Pleistocene Park, using de-extinction science to resurrect recently lost species like the dodo and thylacine, or revitalizing critically endangered animals such as the northern white rhino, cloning techniques are emerging as powerful tools for conservation and genetic restoration. This modern technology may offer humanity the opportunity to correct some of our greatest ecological mistakes, particularly the mass extinctions and environmental destruction we've caused.

History of the Mammoth Steppe and the Vision of Pleistocene Park

During the last Ice Age, the Mammoth Steppe was the largest and most productive grazing ecosystem, spanning from Spain to Canada and from the Arctic to China (Shapiro and Lister 2005). It was sustained by millions of large herbivores, including mammoths, bison, and horses, and was ecologically resilient, thriving across diverse climates and persisting through both glacial and interglacial cycles. 

However, the expansion of humans into Northern Eurasia around 14,500 years ago coincided with the decline of these megafauna populations. This reduction in herbivores triggered a significant ecological shift, notably by the loss of grasslands and the growth of slower-growing mosses, shrubs, and trees. Without the megafauna grazing the land, plant matter accumulated, which slowed nutrient cycling and allowed less productive vegetation to replace the fertile grasslands. As a result, large herbivores like mammoths and woolly rhinoceroses were no longer able to find enough food to survive the harsh winters. This scenario illustrates how fragile ecosystems really can be when a new component, oftentimes humans, are introduced (Pleistocene Park 2025).

Since humans may have been responsible for the destruction of the Mammoth Steppe over 10,000 years ago, it could be our obligation to restore it. This belief drives the founders of Pleistocene Park, who aim to revive the steppe’s once-thriving ecosystem and diverse wildlife. In 1989, Sergey A. Zimov and his colleagues launched a long-term project, Pleistocene Park, to reestablish this lost environment. Reintroducing grazing herbivores could transform the Arctic into a highly productive ecosystem, akin to the Northern Serengeti. This restoration could even help combat climate change by locking carbon in the permafrost. As large herbivores compact the snow, they enable deeper freezing, preventing permafrost from thawing. Cold-tolerant elephant-mammoth hybrids grazing the grasslands and roaming during winter would further aid this process by scraping away snow layers, allowing frigid air to penetrate the soil more effectively. 

Additionally, grasses’ deep root systems store carbon, and their lighter surfaces reflect more sunlight, cooling the region through the albedo effect—and their presence reduces methane emissions by drying out the soil and preventing its release (Pleistocene Park 2025).

The Science of De-Extinction

Pleistocene Park’s efforts to potentially introduce woolly mammoth clones into their ecosystem naturally evoke concerns reminiscent of Michael Crichton’s Jurassic Park and its film adaptations by Steven Spielberg. While both involve the resurrection of extinct species, their objectives and implementation differ significantly. 

Unlike the fictionalized and scientifically flawed cloning methods in Jurassic Park, Pleistocene Park is grounded in real-world genetics and ecological restoration methods with the goal of restoring a lost ecosystem to combat climate change and promote biodiversity in the Arctic. Furthermore, while cloning woolly mammoths is a potential aspect of the project, it is not the park’s primary objective. The restoration effort could be achieved with other large herbivores, though the presence of mammoth herds would likely accelerate the process by more effectively compacting snow and transforming the landscape into a highly productive grazing ecosystem.

That being said, de-extinction practices such as cloning present a fascinating scientific and ethical quandary, one that is actively explored through initiatives like Pleistocene Park. De-extinction refers to the process of recreating extinct species through biotechnology, offering both potential ecological benefits and complex ethical considerations. This has led scholars, geneticists, and molecular biologists, among others, to identify potential de-extinction candidates.

The woolly mammoth is perhaps the most viable candidate, as its DNA has been well-preserved in permafrost, and much of its genome persists in its closest living relative, the Asian elephant. Leading the efforts to clone the mammoth is Colossal Laboratories & Biosciences. This ambitious effort has multi-faceted goals, including: increasing the resilience of habitats to climate change and environmental upheaval, developing tools to save modern elephants from extinction, understanding the genetic basis of cold adaptation in animals, driving advancements in multiplex genome editing, and demonstrating the possibility of bringing back extinct megafauna species (Colossal 2025).

While the woolly mammoth and the Asian elephant share 99.6% of their DNA, scientists at Colossal are using CRISPR genome editing to bridge the remaining 0.4% of the genetic sequence, which would result in a successful mammoth-elephant hybrid species (Colossal 2025).

The Future of De-Extinction

Photo of Woolly Mouse by Colossal Biosciences

The significance of this endeavor could certainly be one of the most impactful in modern history. As Richard Garriott, astronaut and member of Colossal’s Executive Advisory Board, put it, “If you think about the most important headline of the 20th century, unquestionably it was humans landing on the moon. In the 21st century, bringing an extinct species back to life would hold similar weight in the history of humanity. It is hard to imagine a more profound project than the de-extinction of species once considered lost forever.” 

This perspective underscores the potential of de-extinction to become one of the defining scientific achievements of our time, reshaping conservation efforts and redefining humanity’s relationship with the natural world (Colossal 2025).

Recently, Colossal successfully bio-engineered the “Colossal Woolly Mouse,” a groundbreaking achievement featuring a mix of mutations that notably altered hair growth in mice, resulting in a light-colored, long-haired specimen. Some consider this a watershed moment in the de-extinction effort, demonstrating how scientists can precisely target specific genes. However, skepticism remains, with Stephan Risenberg, a genome engineer at the Max Planck Institute for Evolutionary Anthropology, cautioning, “It’s far away from making a mammoth or a ‘mammoth mouse.’ It’s just a mouse that has some special genes” (Risenberg 2025).

While this breakthrough was achieved in mice, it lays the foundation for applying similar genetic modifications to the Asian elephant, ultimately paving the way for the creation of mammoth-elephant hybrids. This progress represents a crucial step toward realizing the vision of reviving extinct species, though significant scientific and ethical challenges remain. In the coming years, it will be fascinating to see how researchers build upon these findings to advance the science of de-extinction.

In addition to the mammoth, the Tasmanian tiger (thylacine) is another species being considered for de-extinction. Once widespread across Australia and Tasmania, the thylacine coexisted with modern humans until the 20th century, with the last known individual dying in captivity in 1936. Beyond the thylacine, scientists have also considered the possibility of reviving the dodo bird, a flightless species that went extinct in the late 1600s due to overhunting and the introduction of invasive predators by European sailors (Hengeveld and Nygren 2025).

Interestingly, the northern white rhinoceros is also a candidate for de-extinction efforts. Although not yet classified as extinct, the species is functionally extinct, as only two females remain in the Ol Pejeta Conservancy in Kenya. However, genetic material such as cryopreserved embryos and eggs offers a potential pathway for reviving the species through advanced reproductive technologies (Hengeveld and Nygren 2025). These three examples, amongst many other species, showcase scenarios where species went extinct due to overhunting, human-caused habitat loss, and/or climate change. De-extinction efforts through cloning could serve as a means to mitigate some of the ecological damage caused by human activity. At the very least, these technologies offer species on the brink of extinction a renewed chance at survival.

Conclusion

De-extinction is one of the most aggressive and influential methods for enacting real ecological change. Climate change, ecological devastation, overhunting, habitat loss, and many other unfortunate realities are causing wanton destruction to Earth’s ecology. The reality is that human activity plays a significant role in these environmental challenges, often contributing to the destruction of the natural world in new and unexpected ways. 

Biologists estimate that climate change will drastically reduce global biodiversity, with some predicting that upwards of 35% of plants and animals could become extinct in the wild by 2050, marking Earth’s sixth mass extinction (National Park Service n.d.). While green initiatives help combat climate change, they may be too slow to prevent irreversible damage. Earth needs a more aggressive approach, and that’s where de-extinction practices come in.

De-extinction practices have wide-ranging applications, with bringing back the woolly mammoth being just the tip of the iceberg. Colossal Biosciences believes this technology could have profound implications beyond species revival, particularly in the fight against dangerous diseases. They hope CRISPR-based advancements could lead to breakthroughs in curing diseases—or even preventing them before they emerge. 

Moreover, if scientists can clone an extinct animal, they can certainly clone an extant one—a capability that could be crucial in preserving endangered species and bolstering conservation efforts. As de-extinction science progresses, it will hopefully revolutionize conservation, medicine, and our ability to protect endangered species before it’s too late.

Sources:

Colossal. 2025. “Woolly Mammoth.” Colossal. Accessed March 24, 2025. https://colossal.com/mammoth/.

Hengeveld, Kevin L., and Patrick J. Nygren. 2025. “Reviving the Northern White Rhinoceros: Genetic and Reproductive Challenges.” Biological Conservation 250: 2473882. https://doi.org/10.1080/09505431.2025.2473882.

National Park Service. n.d. “Climate Change and Wildlife.” Point Reyes National Seashore. Accessed March 24, 2025. https://www.nps.gov/pore/learn/nature/climatechange_wildlife.htm.

Pleistocene Park. 2025. “Science.” Pleistocene Park. Accessed March 24, 2025. https://pleistocenepark.ru/science/.

Risenberg, Stephan. 2025. “How Scientists Are Trying to Bring the Mammoth Back.” Nature, March 5, 2025. https://www.nature.com/articles/d41586-025-00684-1.

Shapiro, Beth, and Andrew R. Lister. 2005. “The Genomics of Mammoth Evolution.” Science 310 (5754): 383-384. https://doi.org/10.1126/science.1113442.