[Script Info] Title: [Events] Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So this is a talk about gene drives, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but I'm going to start by \Ntelling you a brief story. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,20 years ago, a biologist\Nnamed Anthony James Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,got obsessed by the idea\Nof making mosquitos Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that didn't transmit malaria. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,It was a great idea,\Nbut pretty much a complete failure. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,For one thing, it turned out to be\Nreally hard Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to make a malaria resistant mosquito. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,James managed it, finally,\Njust a few years ago Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,by adding some genes\Nthat make it impossible\N Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,for the malaria gene\Nto survive inside the mosquito. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But that just created another problem. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Now that you've got malaria-resistant\Nmosquito, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,how do you get it to replace\Nall the malaria-carrying mosquitos? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,There are a couple options, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but plan A was basically to breed up\Na bunch of the new genetically-engineered mosquotos, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,release them into the wild, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and hope that they pass on their genes. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The problem was that you'd \Nhave to release Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,literally 10x the number of native\Nmosquitos to work. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So in a village with 10,000 mosquitos, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,you release an extra 100,000. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,As you might guess, this was not\Na very popular strategy Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,with the villagers. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,(Laughter) Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Then, last January, Anthony James\Ngot an email\N Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,from a biologist named \NEthan Bier. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Bier said that he and his grad student,\NValentino Gantz,\N Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,had stumbled on a tool that could not only\Nguarentee Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that a particular gene trait\Nwould not be inherited, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but that it would spread\Nincredibly quickly. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,If they were right, it would basically\Nsolve the problem\N Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that he and James had been\Nworking on for 20 years. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,As a test, they engineered\Ntwo mosquitos Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to carry the anti-malaria gene Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and also this new tool,\Na gene drive, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,which I'll explain in a minute. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Finally, they set it up so that\Nany mosquitos Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that had inherited the\Nanti-malaria gene Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,wouldn't have the usual white eyes,\Nbut would instead have red eyes. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That was pretty much just \Nfor convenience Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,so they could tell just at a glance\Nwhich was which. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So they took their two \Nanti-malarial, red eye mosquitos Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and put them in a box with 30\Nordinary white-eyed ones Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and let them breed. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In two generations, \Nthose had produced 38,000 grandchildren. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That is not the surprising part. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,This is the surprising part: Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,given that you started with just\Ntwo red-eyed mosquitos Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and 30 white-eyed ones, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,you expect mostly white-eyed\Ndescendents. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Instead, when James opened the box, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,all 38,000 mosquitos had red eyes. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,When I asked Ethan Bier\Nabout this moment, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,he became so excited, tht he was\Nliterally shouting into the phone. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That's because getting only\Nred-eyed mosquitos Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,violates a rule that is the\Nabsolute cornerstone of biology, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Mendelian genetics. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,I'll keep this quick, but Mendelian genetics\Nsays when a male and female mate, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,their baby inherits half of its\NDNA from each parent. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So if our original mosquito was aa\Nand our new mosquito is aB, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,where B is the anti-malarial gene, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,the babies should come out\Nin four permutations: Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,aa, aB, aa and Ba. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Instead, with the new gene drive, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,they all came out aB. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Biologically, that shouldn't\Neven be possible. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So what happened? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The first thing that happened\Nwas the arrival Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,of a gene-editing tool\Nknown as CRISPR in 2012. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Many of you have probably heard\Nabout CRISPR, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,so I'll just say briefly that CRISPR\Nis a tool that allows researchers Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to edit genes very precisely,\Neasily and quickly. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,It does this by harnessing a mechanism\Nthat already existed in bacteria. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Basically, there's a protein\Nthat acts like a scissors Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and cuts the DNA, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and there's an RNA molecule\Nthat directs the scissors Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to any point on the genome you want. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The result is basically a word processor\Nof genes. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,You can take an entire gene out,\Nput one in, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,or even edit just a single letter\Nwithin a gene. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And you can do it in nearly any species. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Okay, remember how I said \Nthat gene drives Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,originally had two problems? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The first is that it was hard\Nto engineer a mosquito Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to be malaria resistant. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That's basically gone now,\Nthanks to CRISPR. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But the other problem was \Nlogistical. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,How do you get your trait to spread? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,This is where it gets clever. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,A couple years ago, a biologist\Nat Harvard named Kevin Esvelt Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,wondered what would happen\Nif you made it so that Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,CRISPR inserted not only\Nyour new gene, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but also the machinery \Nthat does the cutting and pasting. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In other words, what if CRISPR\Nalso copy and pasted itself. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,You'd end up with a perpetual\Nmotion machine for gene editing. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And that's exactly what happened. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,This CRISPR gene drive\Nthat Esvelt created Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,not only guarantees that a trait \Nwill get passed on, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but if its used in the germline cell, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,it will automatically copy and paste\Nyour new gene Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,into both chromosomes of every\Nsingle individual. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,It's like a global search and replace, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,or in science terms, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,it makes a heterozygous trait\Nhomozygous. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So, what does this mean? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,For one thing, it means we have\Na very powerful, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but also somewhat alarming new tool. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Up until now, the fact that gene drives\Ndidn't work very well Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,was actually kind of a relief. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Normally when we mess around\Nwith an organisms's genes, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,we make that thing less evolutionarily fit. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So biologists can make all the mutant\Nfruit flies they want Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,without worrying about it. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,If some escape, natural selection\Njust takes care of it. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,What's remarkable and powerful\Nand frightening about gene drives Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is that that will no longer be true. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Assuming that your trait does not\Nhave a big evolutionary handicap, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,like a mosquito that can't fly, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,the CRISPR-based gene drive\Nwill spread the change relentlessly Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,until it is in every single individual\Nin the population. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Now, it isn't easy to make\Na gene drive that works that well, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but James and Esvelt think\Nthat we can. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The good news is that this opens\Nthe door to some remarkable things. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,If you put an anti-malarial gene drive\Nin just 1 percent Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,of anopheles mosquitos,\Nthe species that transmits malaria. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Researchers estimate that it would\Nspread to the entire population Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,in a year. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So in a year, you could virtually \Neliminate malaria. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In practice, we're still a few years out\Nfrom being able to do that, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but sitll, a 1,000 children a day\Ndie of malaria. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In a year, that number could be\Nalmost zero. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The same goes for dengue fever,\Nchicken genuang (?), yellow fever. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And it gets better. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Say you want to get rid \Nof an invasive species, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,like get Asian Carp out of\NThe Great Lakes. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,All you have to do is release \Na gene drive Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that makes the fish produce\Nonly male offspring. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In a few generations, there'll be\Nno females left, no more carp. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In theory, this means that we \Ncould restore hundreds Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,of native species that have been\Npushed to the brink. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Okay, that's the good news, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,this is the bad news. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Gene drives are so effective, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that even an accidental release \Ncould change an entire species, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and often very quickly. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Anthony James took the precautions. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,He breed his mosquitos in\Na bio-containment lab Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and he also used a species\Nthat's not native to the US Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,so that even if some did escape, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,they'd just die off, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,there'd be nothing for them\Nto mate with. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But it's also true that if \Na dozen Asian Carp Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,with the all-male gene drive accidentally\Ngot carried from The Great Lakes Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,back to Asia, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,they could potentially wipe out \Nthe native Asian Carp population. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And that's not so unlikely, given\Nhow connected our world is. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In fact, it's why we have \Nan invasive species problem. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And that's fish. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Things like mosquitos and fruit flies,\Nthere's literally no way to contain them. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,They cross borders and oceans\Nall the time. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Okay, the other piece of bad news\Nis that Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,a gene drive might not stay confined\Nto what we call the target species. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That's because of gene flow, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,which is a fancy way of saying\Nthat neighboring species Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,sometimes inter-breed. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,If that happens, it's possible\Na gene drive could cross over, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,like Asian Carp could infect\Nsome other kind of Carp. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That's not so bad if your drive\Njust promotes a trait, like eye color. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In fact, there's a decent chance that\Nwe'll see a wave Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,of very weird fruit flies \Nin the near future. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But it could be a disaster\Nif your drive is deigned Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to eliminate the species entirely. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The last worrisome thing is that\Nthe technology to do this, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to genetically engineer an organism\Nand include a gene drive Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is something basically any lab\Nin the world can do. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,An undergraduate can do it. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,A talented high schooler\Nwith some equipment can do it. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Now I'm guessing that this sounds \Nterrifying. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Interestingly though, nearly \Nevery scientist I talk to Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,seems to think that gene drives\Nwere not actually Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that frightening or dangerous. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Partly because they believe that\Nscientists will be Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,very cautious and responsible\Nabout using them. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,(Laughter) Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So far, that's been true. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The gene drives also have\Nsome actual limitations. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,For one thing, they work in only\Nsexually reproducing species. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So thank goodness, they can't be used\Nto engineer viruses or bacteria. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Also, the trait spreads only with each\Nsuccesive genertion. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So changing or eliminating a population\Nis practical only if that species Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,has a fast reproductive cycle,\N Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,like insects or maybe small vertebrates\Nlike mice or fish. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In elephants or people, it would\Ntake centuries Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,for a trait to spread widely enough\Nto matter. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Also, even with CRISPR, it's not that easy\Nto engineer a truly devastating trait. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Say you wanted to make a fruit fly\N Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that feeds on ordinary fruit instead\Nof rotten fruit Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,with the aim of sabotaging \NAmerican agriculture. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,First you'd have to figure out\Nwhich gene controls Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,what the fly wants to eat, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,which is already a very long \Nand complicated project. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Then you'd have to alter those genes\Nto change the fly's behavior Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to whatever you'd want it to be, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,which is an even longer \Nand complicated project. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And it might not even work because\Nthe genes that control behavior are complex. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So if you're a terrorist and have \Nto choose between Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,starting a grueling basic research program Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that will require years \Nof meticulous lab work Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and still might not pan out, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,or just blowing stuff up? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,You'll probably choose the later. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,This is especially true because\Nat least in theory, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,it should be pretty easy to build\Nwhat's called a reversal drive. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,That's one that basically overwrites\Nthe change made by the first gene drive. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So if you don't like the effects \Nof a change, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,you can just release a second drive\Nthat will cancel it out, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,at least in theory. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Okay, so where does this leave us? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,We now have the ability to change\Nentire species at will. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Should we? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Are we gods now? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,I'm not sure I'd say that. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But I would say this: Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,First, some very smart people\Nare even now debating Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,how to regulate gene drives. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,At the same time, some other\Nvery smart people Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,are working hard to create\Nsafeguards, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,like gene drives that self regulate\Nor petter out after a few generations. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But this technology still requires\Na conversation. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And given the nature of gene drives, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that conversation has to be global. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,What if Kenya wants to use a drive\Nthat Tanzania doesn't? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Who decides whether to release\Na gene drive that can fly? Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,I don't have the answer to that question. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,All we can do going forward, I think, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is talk honestly about \Nthe risks and benefits Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and take responsibility for our choices. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,By that I mean, not just the choice\Nto use a gene drive, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but also the choice not to use one. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Humans have a tendency to assume\Nthat the safest option Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,is to preserve the status quo. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But that's not always the case. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Gene drives have risks and those\Nneed to be discussed, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but malaria exists now and kills\N1,000 people a day. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,To combat it, we spray pesticides\Nthat do grave damage to other species, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,including amphibians and birds. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So when you hear about gene drives\Nin the coming months, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and trust me, you will be \Nhearing about them, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,remember that. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,It can be frightening to act, Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but sometimes, not acting\Nis worse. Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,(Applause)