Extinct species always conjure up a lot of thoughts. When humans found bones and evidence of the species' existence, they would try to reconstruct how these creatures looked like, and write stories about what they would be like if they came back to life.
Like in the movie Jurassic Park, scientists dream of finding ancient species. In recent years, with the increasingly sophisticated development of biotechnology, reviving extinct animals is no longer just a dream of science fiction writers.
Currently, a number of biotechnology companies, one of them Colossal Biosciences, are working hard to try and revive extinct species. The extinct animals they wanted to revive were just one, but several species, namely the woolly mammoth, the Thylacine, and the dodo. Why do they do it?
"Is this just human hubris trying to prove that even extinction is not a hindrance? Or is there an added benefit?," asked Sam Westreich, a microbiome scientist in his writing quoted from News Break.
"First, we must understand that while the Jurassic Park films are made for great entertainment, they are not accurate stories about genetics to restore extinct species," he said.
First, continued Sam, scientists need to get DNA from extinct species. Colossal Biosciences is targeting woolly mammoths and thylacines because these animals are still relatively 'recently' extinct, in evolutionary terms.
Most of the woolly mammoths died around 10,500 years ago, at the end of the last Ice Age. Some pygmy species survived until about 4,000 years ago, but their genetics suggests they were destined for extinction and struggled due to inbreeding. The Thylacine survived until 1936, when the last specimen died in captivity.
The Process of Reviving Extinct Animals
"DNA has a half-life of about 521 years. The half-life is how long, on average, it takes half of a substance to decay or degrade. If you had a piece of DNA, about half of the nucleotide bonds would be broken and unreadable after five centuries, " he explained.
But even after obtaining its DNA, scientists can't just pluck a woolly mammoth out of nowhere. It needed a close relative of the extinct species, which could serve as a starting base for modifying it.
Making matters even more complicated is the fact that DNA wasn't the only component to growing mammoths. Even if a baby animal is born with wooly mammoth DNA, it may not be the same as a 'true' mammoth, as it received fetal input from modern elephants.
Colossal has revealed that it plans to use African elephants as surrogates for gene-edited faux-mammoth embryos. The African elephant is larger and less endangered than the Asian elephant, which is technically the closest ancestor of the mammoth, making it a bit easier from a logistical point of view.
Impact on the ecosystem
Reintroducing mammoths and thylacines could disrupt existing ecosystems. As these animals became extinct, others would evolve and adapt to take their place. Will this organism suffer as a result?
Thanks to climate change, the environment these creatures once lived in may have changed drastically. Some of the plants the woolly mammoths ate are also long gone. Would mammoths still be able to survive on their own in the wild, and if not, who would look after them? Will they end up as animals that inhabit the zoo?
The Thylacine also played an important role in the ecosystem as it was an apex predator so it sat right at the top of the food chain. There were no other marsupial apex predators besides the thylacine, so when it went extinct it left a huge gap.
Some researchers argue that efforts to bring back long-lost species may reduce conservation efforts to save existing animals and even increase the risk of loss of biodiversity.