How Scientists Are Trying to Bring Back Extinct Species: The Science of De-Extinction

Imagine walking through a forest and spotting a woolly mammoth, its shaggy coat swaying in the cold wind. Or hearing the echo of a passenger pigeon flock, once numbering in the billions, filling the sky once more. These aren't just scenes from the past or science fiction—scientists today are actively working to bring extinct species back to life.

This ambitious scientific effort, known as de-extinction, is no longer just a dream. Advances in genetics, cloning, and synthetic biology are making it possible to revive lost species, potentially reversing the damage humans have done to ecosystems. But is it really possible? And if so, should we be doing it? Let’s dive into the cutting-edge world of de-extinction.

What Is De-Extinction?

De-extinction refers to the process of reviving species that have gone extinct, either by cloning their DNA, editing the genes of closely related species, or selectively breeding modern animals to bring back lost traits. Scientists are experimenting with several different approaches to accomplish this near-miraculous feat.

The Science Behind Bringing Species Back

1. Cloning: The Jurassic Park Method (Sort Of)

One of the most well-known methods of de-extinction is cloning, the same technique used to create Dolly the sheep in 1996. This process involves taking a nucleus from the preserved cells of an extinct species and implanting it into the egg of a closely related living species. If successful, this could produce a live clone of the extinct animal.

However, cloning has its limitations:

• It requires well-preserved DNA, which is extremely rare for species that have been extinct for a long time.
• No complete dinosaur DNA has ever been found, so resurrecting creatures like T. rex is not currently possible (sorry, Jurassic Park fans!).
• Cloning works best for recently extinct species, like the Pyrenean ibex, which was briefly brought back in 2003—though the clone died shortly after birth due to lung defects.

2. Genetic Engineering: The CRISPR Revolution

A more advanced method involves gene editing, particularly using the powerful CRISPR-Cas9 tool. Instead of cloning an extinct species directly, scientists can edit the DNA of a closely related species to recreate many of the lost traits.

For example:

• The Woolly Mammoth Project – Scientists are using CRISPR to modify the DNA of modern Asian elephants (the mammoth’s closest relatives) by inserting genes for thick fur, cold resistance, and fat storage, traits that made mammoths adapted to the Ice Age. The goal is to create a mammoth-like hybrid that could help restore the Arctic tundra ecosystem.
• Bringing Back the Passenger Pigeon – Researchers are modifying the genome of modern band-tailed pigeons to give them the characteristics of the extinct passenger pigeon, once a keystone species in North American forests.

This method doesn’t create a perfect copy of the extinct species but produces a genetically similar version that can fill the same ecological role.

3. Selective Breeding: Resurrecting Traits from the Past

Some scientists are using selective breeding to bring back traits from extinct species that still exist in the DNA of living relatives.

One famous example is the Aurochs, the massive wild ancestor of modern cattle, which went extinct in the 1600s. Through careful breeding of cattle that still carry aurochs genes, researchers are attempting to recreate an animal similar in size, behavior, and appearance to its extinct ancestor.

This technique works well for species that have been recently extinct and still have living relatives, but it can’t fully restore lost genetic diversity.

Which Species Are Scientists Trying to Bring Back?

Several projects are currently underway to revive extinct species, including:

• Woolly Mammoth – Colossal Biosciences, a biotech company, is leading efforts to bring back mammoth-like elephants by 2028.
• Passenger Pigeon – Revive & Restore, a conservation group, is using gene editing to create a modern version of this once-abundant bird.
• Tasmanian Tiger (Thylacine) – Researchers in Australia are working on reintroducing thylacine traits into modern marsupials.
• Dodo – Yes, scientists are seriously considering bringing back the dodo, the flightless bird that disappeared in the 1600s due to hunting and invasive species.

Why Bring Back Extinct Species?

The idea of resurrecting extinct species isn’t just about curiosity—it has real ecological benefits.

• Restoring Ecosystems – Many extinct species played key roles in their environments. For example, mammoths helped maintain Arctic grasslands, which could slow climate change by preventing permafrost from melting.
• Correcting Human-Caused Extinctions – Many species went extinct due to overhunting, habitat destruction, and human activity. Some scientists argue that we have an ethical responsibility to bring them back.
• Advancing Genetic Science – De-extinction research is pushing the boundaries of genetics and conservation, leading to breakthroughs that could also help endangered species today.

The Ethical Dilemmas and Risks of De-Extinction

Despite its exciting possibilities, de-extinction comes with serious ethical and practical concerns:

1. Would These Animals Have a Place in the Modern World? – The environments they lived in have changed drastically. Could a mammoth survive in today’s Arctic? Would a passenger pigeon find enough forest to support its massive flocks?
2. Would It Take Attention Away from Saving Endangered Species? – Some argue that resources should be focused on protecting species on the brink of extinction, rather than bringing back those that are already gone.
3. Could Reintroduced Species Become Invasive? – If an extinct species were reintroduced, it might disrupt modern ecosystems, competing with existing wildlife or spreading diseases.
4. Would They Be Truly "Back"? – Many de-extinct animals wouldn’t be exact copies of their ancestors but hybrids or genetic approximations. Would they still count as the original species?

Are We Playing God? Or Fixing Past Mistakes?

The question of whether we should bring back extinct species remains hotly debated. Some see de-extinction as human arrogance, interfering with nature in unpredictable ways. Others see it as a chance to undo the damage humans have done and restore lost parts of our natural world.

What’s clear is that the technology is advancing rapidly, and within the next few decades, we may see extinct species walk the Earth once again. Whether that’s a scientific triumph or a cautionary tale is something only time will tell.

One thing’s for sure—if we ever see mammoths roaming the tundra, history will have come full circle, proving that in the age of genetic science, extinction might not be forever.