What Alida Bailleul saw under the microscope made no sense. She was examining thin sections of the fossilized skull of a young hadrosaurus, a duck-billed beast and eating plants that roamed what is now Montana 75 million years ago, when she saw features that made her breathe.
Bailleul was inspecting fossils from a collection at the Rocky Mountain Museum in Bozeman, Montana, to understand how dinosaur skulls developed. But what caught his eye shouldn’t be there, according to the textbooks. Embedded in the calcified cartilage at the back of the skull was what appeared to be fossilized cells. Some contained tiny structures that looked like nuclei. In one was what looked like a group of chromosomes, the threads that carry the DNA of an organism.
Bailleul showed the specimens to Mary Schweitzer, a professor and specialist in molecular paleontology at North Carolina State University, who was visiting the museum. Schweitzer had done his PhD in Montana under the supervision of Jack Horner, the resident fossil hunter who inspired Jurassic Park character Alan Grant. Schweitzer herself had become famous and had faced waves of criticism for claiming to have found soft tissue in dinosaur fossils, from blood vessels to protein fragments.
Schweitzer was intrigued by Bailleul’s discovery, and the two joined forces to study the fossils further. In early 2020, as the world faced the arrival of Covid, they published a bombshell article about their findings. His report presented not only tests of dinosaur cells and nuclei in hadrosauce fossils, but also results of chemical tests pointing to DNA, or something similar, coiled inside.
I don’t think we should rule out obtaining dinosaur DNA from dinosaur fossils, but we won’t if we don’t keep looking for Mary Schweitzer
The idea of recovering biological material from dinosaur fossils is controversial and profound. Schweitzer does not claim to have found dinosaur DNA (the evidence is too weak to be certain), but says scientists should not rule out the possibility that it may have persisted in prehistoric remains.
“I don’t think we should ever rule out getting dinosaur DNA from dinosaur fossils,” he says. “We’re not there yet, and we may not find it, but I guarantee we won’t if we don’t keep looking.”
Prehistoric pieces of tissue, protein, or DNA could transform the field of molecular paleontology and unravel many of the mysteries of dinosaur life. But the prospect of having the genetic code of a tyrannosaurus or velociraptor intact raises questions that scientists have been accustomed to asking since the original Jurassic Park movie in 1993. Armed with enough dinosaur DNA, we could recover the beasts. heavy?
Woolly mammoth artist print. Photography: David Fleetham / Alamy
Rapid advances in biotechnology have paved the way for elegant approaches to extinction, where a species that was once considered lost forever has a second chance at life on Earth. For now, the focus is on the creatures that humans shared the planet with, and that we helped make out of existence.
Undoubtedly, the most prominent extinction program aims to recreate, in some way, the woolly mammoth and return the herds of beasts to the Siberian tundra thousands of years after their extinction. The company behind the company, Colossal, was founded by Harvard geneticist George Church and Ben Lamm, a technology entrepreneur, who say thousands of woolly mammoths could help restore degraded habitat – for example, by felling trees. fertilizing the soil with its manure and encouraging the regrowth of the prairies. If all goes well, and maybe not, the first calves could be born in six years.
What awaits us is a formidable challenge. Although well-preserved mammoths were excavated from the tundra, no living cells were found other than clones using the approach produced by Dolly the sheep, the first cloned mammal. So Colossal has come up with an alternative solution. First, the team compared the genomes of the woolly mammoth and a close relative, the Asian elephant. This revealed genetic variants that equipped the woolly mammoth for the cold: the thick layer of hair, the shortened ears, the thick layers of fat for isolation, and so on.
The next step is to use gene editing tools to rewrite the genome of an Asian elephant cell. If the expected 50 editions have the desired effect, the team will insert one of the “mammothed” elephant cells into an Asian elephant egg whose core has been removed. An electric shock will be applied to cause fertilization and the egg should begin to divide and grow into an embryo. Eventually, the embryo will be transferred to a surrogate mother or, given the goal of producing thousands of babies, an artificial uterus that the fetus can carry.
The Colossal project highlights one of the biggest misunderstandings about extinction programs. Although there is talk of returning species, these will not be copies of extinct animals. The Colossal Woolly Mammoth, as Church readily admits, will be a modified elephant to survive the cold.
Whether this is important depends on the reason. If the goal is to restore the health of an ecosystem, then the animal’s behavior exceeds its identity. But whether the engine is nostalgia or an attempt to alleviate human guilt to destroy a species, extinction may be little more than a scientific strategy to deceive ourselves.
Elizabeth Ann, the first cloned black-footed ferret, about seven weeks old. Photo: US Fish & Wildlife Service / AP
The California-based nonprofit Revive and Restore has ongoing projects to help revive more than 40 species through the astute application of biotechnology. The organization has cloned a black-footed ferret named Elizabeth Ann, which will become the first cloned mammal to help save an endangered species. The hope is that Elizabeth Ann, which was created from frozen cells in the 1980s, will bring much-needed genetic diversity to wild ferret colonies that are threatened by inbreeding.
Revive and Restore intends to recover two extinct bird species, the heather hen and the traveling pigeon, as early as the 2030s. Massachusetts, the heather hen became extinct in 1932. According to the extinction plan, scientists will create a replacement bird by editing the DNA of the prairie chicken closely related to carrying heather hen genes. The passenger pigeon project has a similar approach, using the tail pigeon as a genetic template.
Ben Novak, the lead scientist at Revive and Restore, compares extinction to rescue efforts to reintroduce lost species to improve local habitats. “The introduction of biotechnology is simply to expand this existing practice so that we can consider species that were previously off the table,” he says. It doesn’t make sense to worry that animals created through extinction projects are not exact replicas of lost species, he adds. “We are not recreating these species to satisfy human philosophy, we are doing it for conservation purposes. For conservation, what matters is an ecosystem, and ecosystems do not sit to pontificate on classification schemes,” he says.
Should humans try to prevent all future extinctions? Each species dies at some point. But while extinction is normal in the evolution of ecosystems, human activity is pushing species to the limit faster than most species can adapt. Novak says preventing all extinctions is a “good goal,” but the reality, he adds, is that the world’s governments have not prioritized conservation over exploitation. “No matter how many people work really hard, we have the majority of humanity still working against that goal,” he says. “What we can do is prevent as much as possible right now and re-diversify the world in a way that gives us ecological stability to prevent further extinctions.”
The dodo: without a habitat where it can thrive, it makes no sense to resurrect it. Photo: Leemage / Corbis / Getty Images
The dodo is a major candidate for extinction. Once native to Mauritius (and only Mauritius), the large, non-flying bird became extinct in the 17th century after humans settled on the island. In addition to the widespread destruction of their habitat, the dodo was even more threatened by the pigs, cats and monkeys that the sailors brought with them.
A team led by Beth Shapiro, a professor of ecology and evolutionary biology at the University of California, Santa Cruz, has sequenced the dodo genome of a museum specimen in Copenhagen. In theory, a dodo-like bird could be created by editing the genome of the Nicobar pigeon to contain dodo DNA, but, as with all extinction projects, it is not enough to create the animal. ‘have a habitat to thrive. , or the exercise becomes useless.
“I think it’s crucial that, as we prioritize species and ecosystems for their protection, we do so with a view to what our planet will be like in 50 or 100 years, rather than imagining that somehow we can turn back the clock and restore the ecosystems of the past, “says Shapiro.
“The biggest problem facing many species today is that the rate of change in their habitats is too fast for evolution to keep up. This is where our new technologies can come in handy. We can sequence genomes and We can resurrect lost diversity through cloning, such as Elizabeth Ann, the black-footed ferret, and we can even move adaptive traits between populations and species.Our new technologies can enable us to grow to which the species can adapt, perhaps saving some of the same fate as the dodo and the mammoth, “he added.
The preserved carcass stuffed with a young woolly mammoth, found frozen in Siberia. Photo: VPC Travel Photo / Alamy
Most extinction projects are viable because researchers have living cells or …