New technologies could make it possible to bring extinct species back to life, concludes a paper published on April 4 in the journal Science. These advances include back-breeding (assembling or reassembling an extinct species' genes), cloning and genetic engineering.
A leading candidate for de-extinction is the woolly mammoth. Russian scientist Semyon Grigoriev, of the Sakha Republic's mammoth museum, plans to replace the nuclei of an elephant egg with nuclei extracted from woolly mammoth bone marrow. The elephant would theoretically become a surrogate mother to a baby mammoth.
Tasmanian tigers died out in 1936, in part because they had little genetic diversity which translates to "bad news for a species," said Katherine Belov, professor of comparative genomics at the University of Sydney. "Species are less able to adapt to change." Even if Tasmanian tigers -- or other animals -- are resurrected, it will take some time to build up diversity again.
Louis Agassiz Fuertes, Wikimedia Commons
Experts believe billions of these birds populated the Americas when Europeans arrived. Loss of habitat and commercial exploitation of the birds for their meat are thought to have killed them all off.
Efforts are now underway to revive the species by extracting DNA fragments from preserved specimens, and later, using band-tailed pigeons as surrogate parents.
Joseph Wolf, Wikimedia Commons
The Pyrenean ibex, a horned mammal once common in Europe, was one of the first subspecies targeted for de-extinction. Scientists began the attempts in late 1990s, when the last female Pyrenean ibex was still alive. Even if researchers could successfully clone that individual, there would be no males for her to breed with. Instead, genetic engineering might be required.
Cicero Moraes, Wikimedia Commons
Since saber-toothed cat bodies are sometimes found frozen, it might be possible to extract preserved DNA and clone the animal. About 5 years ago, scientists did just that with a mouse that was dead and frozen for 16 years. Woolly mammoth remains are also sometimes found in a well-preserved, frozen state.
Oxford Museum of Natural History, Wikimedia Commons
The dodo, a flightless bird, proved to be a tasty meal for humans and other predators. In 2007, scientists found a remarkably well-preserved dodo in a cave. Dodo DNA could be used to resurrect this avian species.
University of Texas at Austin, Wikimedia Commons
Ground sloths, relatively slow, lumbering animals, were easy targets for prehistoric big-game hunters. Scientists have found remains that still bear soft tissue. As with woolly mammoths, there's a chance extracted DNA could be used to back-breed or clone the large sloths.
Charles Knight, Wikimedia Commons
The Irish elk has been extinct for 11,000 years. Like the woolly mammoth, it inhabited colder regions. As a result, bodies are sometimes found frozen and in relatively good condition, making them candidates for DNA extraction.
UNiesert, Wikimedia Commons
Earlier this year, Harvard geneticist George Church -- with tongue in cheek -- said that he was seeing an "adventurous female human" to be a surrogate mother to a cloned Neanderthal. While Church was really just theorizing about what it would take to bring a Neanderthal back to life, the possibility could be a reality, should any scientist undertake such a controversial project.
Paleontologist Jack Horner is leading a project to create a dinosaur out of a chicken -- a "dinochicken." He told Discovery News that birds "are dinosaurs, so technically we're making a dinosaur out of a dinosaur." He and his colleagues have been genetically engineering chickens to reactivate ancestral traits, such as long tails, which are more associated with non-avian dinosaurs.
A 9,300-year-old frozen bison mummy has been found in Eastern Siberia, according to a presentation this week at the Society of Vertebrate Paleontology’s Annual Meeting in Berlin.
The still-furry beast is one of the most complete frozen mummies ever found. It literally freezes in time the appearance and anatomy of a steppe bison (Bison priscus), whose species went extinct shortly after the end of the Ice Age.
It’s been named the “Yukagir bison mummy,” after the region where it was found.
“The exceptionally good preservation of the Yukagir bison mummy allows direct anatomical comparisons with modern species of bison and cattle, as well as with extinct species of bison that were gone at the Pleistocene-Holocene boundary,” co-author Evgeny Maschenko from the Paleontological Institute in Moscow was quoted as saying in a press release.
The remarkable specimen still has its complete brain, heart, blood vessels and digestive system. Some of its organs have significantly shrunk over time, but that’s to be expected given its advanced age.
The researchers, led by Natalia Serduk of the Russian Academy of Sciences in Moscow, conducted a necropsy on the remains. The investigation determined that the bison showed a relatively normal anatomy. A clue to its demise, however, is a lack of fat around its abdomen. This suggests that the bison died from starvation, but the scientists aren’t sure of that yet.
Compared to today’s bison in America, the Ice Age bison sported much larger horns and a second back hump. Steppe bison like this now-frozen one were commonly featured in Stone Age cave art, often shown being hunted by humans.
Remains for a woolly rhino, a 35,000–39,000-year-old horse, and a mammoth were also recently found near the Siberian site where the bison mummy was discovered.
“The next steps to be done include further examination of the bison’s gross anatomy, and other detailed studies on its histology, parasites, and bones and teeth,” co-author Olga Potapova said.
She added, “We expect that the results of these studies will reveal not only the cause of death of this particular specimen, but also might shed light on the species behavior and causes of its extinction.”
Photo: The Yukagir bison mummy. Credit: Boeskorov et al, Integrative Zoology