Resurrecting extinct species won’t do biodiversity any favours, says researcher
Everyone familiar with Jurassic Park knows resurrecting extinct species does not end well for humans.
But Carleton University biologist Joseph Bennett argues that “de-extinction” is not a good idea for reasons other then the possibility of ending up as a T-rex snack. Scarce conservation funding is much better spent preserving threatened species that are still with us, he says.
In a paper to be published in the journal Nature Ecology & Evolution, Bennett and his co-authors argue that spending scarce funds on de-extinction might cause “perverse outcomes” that will actually lead to a loss in biodiversity.
“Better to spend the money on the living than the dead,” says Bennett, who specializes in conservation prioritization and invasion ecology.
There’s a race on to bring animals back from extinction. The woolly mammoth, an Ice Age giant that disappeared about 4,000 years ago, has been the most riveting example. Just last month, scientists said that within a few years they expect to resurrect the mammoth — in revised form — by creating a hybrid embryo containing genetic traits from the mammoth, taken from the DNA of freeze-dried mammoths found preserved in ice, and living Asian elephants. The resulting animal has been dubbed a “mammophant.”
“Actually, it would be more like an elephant with a number of mammoth traits. We’re not there yet, but it could happen in a couple of years,” George Church, who is leading a Harvard University team, told reporters.
But it’s far from a done deal. Knowledge is moving forward at a fast pace, but de-extinction has proven difficult. In 2003, the Pyrenean ibex, which had had been extinct since 2000 was briefly resurrected using the DNA from one of the last females and a goat surrogate. The baby ibex was born with a lung deformity and survived only seven minutes.
The woolly mammoth DNA is degraded, and the project will take a lot of elephant DNA, says Bennett. An elephant would have to be a surrogate mother to a baby mammoth, and that’s questionable both biologically and socially. “It would be like having a gorilla surrogate mother to a human.”
The big question is whether genetic engineering could ever produce a breeding population, and whether mammoths could be released into the Arctic. Other animals, such as caribou, are already under stress because of climate change.
“The Arctic is not the same as when the mammoth went extinct,” says Bennett.
If it ever gets to the point where resurrected species could be re-introduced, there are three scenarios.
The first is that the resurrected animals would not thrive in their changed environment. This is considered a highly likely possibility, says Bennett.
The “Goldilocks” scenario would see the reintroduced species thriving, creating a benefit for biodiversity. Proponents of de-extinction have argued that resurrected animals can play a role as “ecosystem engineers.” Church argues, for example, that reintroducing mammoths to the Arctic would help to combat global warming by preventing tundra permafrost from melting by punching through snow, allowing cold air to come in.
In the third scenario, the reintroduced species would put stress on the species that have moved into its biological niche since its extinction.
In their paper, Bennett and a group of colleagues in New Zealand and Australia worked on the assumption that it would be possible to resurrect some extinct species. Then they did a cost-benefit analysis using 11 extinct species in New Zealand and another five for New South Wales in Australia.
In New Zealand, the list of species included the smallest kind of moa, a small flightless bird about the same size as a kiwi. In Australia, it included the mainland bettong, a subspecies of the small marsupial known as the “rat kangaroo.” All of the extinct species on the lists have “analogs” — that is, living species that share a habitat with a resurrected species, so human conservation efforts would benefit both.
Two things could happen, say the researchers. In the first scenario, the resurrected species could become a burden on government funds and essentially take limited funding away from conservation efforts from existing threatened animals. In the New Zealand example, government-funded conservation for 11 extinct species would sacrifice conservation funding for nearly three times the number of extant species.
In the other scenario, sponsors such as private organizations or corporations would pay for conservation efforts for resurrected species. There could be biodiversity benefits, but there would also be costs for the existing species, says Bennett. In the Australian example, sponsored funding for the five extinct species could have been used for conservation efforts for more than eight times as many existing species.
The scenarios in the paper all involve animals that have been extinct for less than 1,000 years. This is not Jurassic Park crawling with dinosaurs.
Bennett doesn’t have a philosophical problem with extinction tourism. It’s a matter of creating priorities with limited resources, he says. The World Wildlife Fund estimates that there are between 200 and 2,000 extinctions every year. New species unknown to science are constantly being discovered, so it’s impossible to say how many species there are in the first place.
“A lot of people would like to look a mammoth in the eye,” says Bennett. “But we have to ask ourselves if we could have done something different with the money.”
Other species under consideration for “de-extinction”
Passenger pigeon: Once believed to be the most numerous bird in North America, the last passenger pigeon died in a zoo in 1914. The bird might take flight again thanks to DNA harvested from museum specimens.
Heath hen: A sub-species of the prairie chicken, this bird was once common in New England until it was over-hunted. Conservation efforts began in the 1870s, but the population was wiped out in the 1930s.
Aurochs: This ancient species of wild cattle was the ancestor of the domestic cow, but it was driven to extinction due to over-hunting. The last specimen died in 1627 in Poland. Researchers hoping to “rewild” Europe are selectively mating existing breeds of cattle that retain the aurochs’ DNA.
Tasmanian tiger or thylacine: This striped carnivorous marsupial had already disappeared in Australia when European settlers arrived, but survived in Tasmania until the 1930s. Amid skepticism, the Australian Museum began a closing project in 1999 using genetic material from preserved specimens. In 2008, scientists said they had “resurrected” a gene.