字幕表 動画を再生する 英語字幕をプリント Will our science fiction future include the prehistoric past? We're all familiar with the story of Jurassic Park. The eccentric billionaire pays a bunch of scientists to genetically resurrect dinosaurs for his amusement park and hilarity ensues. So, how realistic is this scenario? Well, for dinosaurs, the sad answer is not very realistic, because DNA degrades over time. Dinosaurs lived millions of years ago. So being able to sequence the genome of a dinosaur looks to be impossible. Even with the mosquito in amber scenario. But the same is not necessarily true for animals that went extinct more recently, like in the last ten thousand years or so. In fact, it's not just a hypothesis, scientists are working on it right now. Back in 2003, a team of scientists attempted to clone a bucardo, which is an extinct animal that's similar to a goat. They harvested nuclei out of bucardo cells, and then they put that into empty goat egg cells and then into goat surrogate mothers. After several attempts, they had a live bucardo delivered by c-section. Sadly, it only lived a few minutes. But it laid the ground work for the future. And since then, techniques and technologies have improved and scientists are now on the verge of being able to bring back several extinct species. And they don't necessarily need a viable cell to do it. Another approach is create a chimera, which is an animal that, on the outside, resembles one species, and on the inside resembles another. This is how scientists plan to bring back the passenger pigeon. They're going to reconstruct passenger pigeon DNA, and inject it into band-tailed pigeon eggs. Now the hatchlings are going to look like band-tailed pigeons. They're going to act like band-tailed pigeons. But they're going to have the reproductive cells of passenger pigeons. So if you breed two of these altered band-tailed pigeons together... BAM! You've got passenger pigeons! Now the question is - is this a good idea? I would love to see flocks of passenger pigeons flying around, or even a woolly mammoth walking by. How cool would that be? But some people are a little worried that this de-extinction technology could lead to less importance placed on conservation. Why should we spend money and effort conserving a species, if we can just bring them back from the dead, should they go extinct? Now using this same sort of flawed logic you could see people decide to exploit the environment even more than we already are. And another drawback is that some extinct species may not be able to survive in today's ecosystems. And it hardly seems fair to bring a species back from the dead, just for it to go extinct again. But this doesn't mean de-extinction technology is a bad idea. It's actually an amazing idea! For one thing, it can help us bring endangered species back from the brink of extinction by increasing biodiversity in these small populations. And who knows, maybe the reason why traffic is so bad in the morning is because the woolly mammoth crossing is particularly busy today. Now that leads me to a question for all of you this week. If you could bring one species back from extinction, which one would it be and why? Let us know in the comments below. And if you enjoyed this video, please share it with your friends and hit that little 'like' button and subscribe to our channel. And then treat yourself. Watch one of these videos over here. You're gonna love it.