Sloths don’t typically seem like intimidating creatures. They sleep for most of the day and move so slowly they look like they’re sleepwalking. Their ancestors, though, were 20 feet long and could reach the tops of palm trees while standing upright. They weighed about 3 tons and left footprints 3 feet long. They also lived right here in Wilmington.
Known as giant ground sloths, they roamed local land approximately 1.5 million years ago. A replica stands in the Cape Fear Museum, but the real skeleton is on display at the North Carolina Museum of Natural Sciences in Raleigh, after construction workers found the remains near Randall Parkway in 1991. Yet, what currently looks like a pile of bones now has the potential to become a living creature once again.
“Scientists are actively researching ways to bring back these species,” says Dr. Nathan Crowe, a professor of history at UNCW who studies the history of science and cloning and how society perceives it. He is introducing the Cape Fear Museum’s “What’s Brewing in Science: De-Extinction?” at Waterline Brewery on Wednesday. Museum employees and fellow UNCW professors will discuss technological advancements which have the ability to resurrect extinct animals. They also will discuss societal effects the process could have.
“People generally think of ‘Jurassic Park’ when you bring up de-extinction,” Dr. Crowe says. “There is an excitement because of this connection, but how much are people thinking about the realities of it?”
One of the discussion goals is to educate the public about what de-extinction—i.e. the process of bringing back an extinct species—really means and how it differs from the famous film franchise.
“There are three main ways of doing that,” Dr. Crowe explains. “The first is back breeding: Living animals are selectively bred to produce the traits of their ancestors. The second is cloning: The nucleus of an extinct animal cell is placed within a living egg cell to develop into an embryo. And the third is genetic engineering: Sections of DNA containing ancestral traits are copied and pasted into living animal cells.”
The one aspect of de-extinction “Jurassic Park” did get right, though, is genetic engineering: the most likely way ancient species will walk the Earth once again. Unfortunately for dinosaur fans, the process of bringing back a dinosaur isn’t as easy as extracting their DNA from mosquitoes.
“You need living samples from an extinct species to bring them back, but you also need a closely related species living today to act as a surrogate,” he says. “That’s why most of the animals we are trying to bring back are ones that went extinct in the 1990s and have had their living tissue preserved.”
Dr. Crowe confirms, even with living samples from extinct species, the process is still difficult and often only has about a 5-percent chance of working. An example of can be seen with the Pyrenean subspecies of the Spanish ibex, which became extinct in 2000. Researchers used a goat as a surrogate mother for the Pyrenean Spanish ibex embryos they created, but few of them made it to gestation. The one embryo that made it to birth died soon after from physical defects.
Such variables are not the only ones researchers must worry about. According to Dr. Crowe, we should ask whether other resources need more of our attention, like conservation of current endangered animals. We should also weigh whether the animals we bring back from extinction will be the same as they once were.
“Is a mammoth a mammoth if there are no other mammoths?” he asks. “We have to think about what value bringing these animals back will have. If their habitat and population are gone, is there really any value in that?”
While for some people it may seem exciting for giant ground sloths to once again roam Wilmington, it is important to consider the type of lives they would live among communities built in the time since their deaths. With little space to get around like they used to, and little chance of ever repopulating their species, would bringing back the giant ground sloth have value? Would it be more burden than benefit?
“Some would argue bringing back these species could help us,” Dr. Crowe answers, “like how reintroducing wolves into Yellowstone resulted in plant and other animal populations of the park thriving. But there are too many unknowns to realistically guess what the effects of de-extinction could be or even how long until it is accomplished. The process is too new to really anticipate what will happen.”
Despite the many unknowns that come with the topic of de-extinction, there are still scientists who dedicate research to making it happen. Harvard University does as well, and is currently researching how to resurrect mammoths via mutations in African elephants.
“There are some groups selectively breeding cows to try and bring back aurochs,” Dr. Crowe notes. “There is a group in Germany actively sequencing the Neanderthal genome. They have even had women volunteer as surrogates for a Neanderthal baby.”
With a popular film franchise like “Jurassic Park” and numerous research projects dedicated to the subject, de-extinction is more popular now than ever. Dr. Crowe hopes his discussion and others will facilitate more conversations about the topic, and the realities of bringing back extinct species versus the public’s perceived beliefs.
“Humans are fascinated with de-extinction even though we are directly responsible for these species going extinct,” he says. “I think we are fascinated by it because it means we might be able to reverse what we have caused.”