What ants teach us about the brain, cancer and the Internet
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0:01 - 0:03I study ants
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0:03 - 0:06in the desert, in the tropical forest
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0:06 - 0:08and in my kitchen,
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0:08 - 0:12and in the hills around Silicon Valley where I live.
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0:12 - 0:13I've recently realized that ants
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0:13 - 0:16are using interactions differently
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0:16 - 0:17in different environments,
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0:17 - 0:19and that got me thinking
that we could learn from this -
0:19 - 0:21about other systems,
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0:21 - 0:26like brains and data networks that we engineer,
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0:26 - 0:29and even cancer.
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0:29 - 0:31So what all these systems have in common
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0:31 - 0:34is that there's no central control.
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0:34 - 0:38An ant colony consists of sterile female workers --
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0:38 - 0:40those are the ants you see walking around —
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0:40 - 0:42and then one or more reproductive females
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0:42 - 0:44who just lay the eggs.
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0:44 - 0:46They don't give any instructions.
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0:46 - 0:48Even though they're called queens,
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0:48 - 0:51they don't tell anybody what to do.
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0:51 - 0:54So in an ant colony, there's no one in charge,
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0:54 - 0:57and all systems like this without central control
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0:57 - 1:01are regulated using very simple interactions.
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1:01 - 1:03Ants interact using smell.
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1:03 - 1:05They smell with their antennae,
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1:05 - 1:08and they interact with their antennae,
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1:08 - 1:11so when one ant touches another with its antennae,
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1:11 - 1:13it can tell, for example, if the other ant
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1:13 - 1:14is a nestmate
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1:14 - 1:19and what task that other ant has been doing.
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1:19 - 1:22So here you see a lot of ants moving around
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1:22 - 1:24and interacting in a lab arena
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1:24 - 1:27that's connected by tubes to two other arenas.
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1:27 - 1:30So when one ant meets another,
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1:30 - 1:32it doesn't matter which ant it meets,
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1:32 - 1:34and they're actually not transmitting
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1:34 - 1:37any kind of complicated signal or message.
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1:37 - 1:39All that matters to the ant is the rate
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1:39 - 1:42at which it meets other ants.
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1:42 - 1:45And all of these interactions, taken together,
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1:45 - 1:47produce a network.
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1:47 - 1:50So this is the network of the ants
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1:50 - 1:52that you just saw moving around in the arena,
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1:52 - 1:56and it's this constantly shifting network
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1:56 - 1:58that produces the behavior of the colony,
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1:58 - 2:01like whether all the ants are hiding inside the nest,
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2:01 - 2:04or how many are going out to forage.
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2:04 - 2:05A brain actually works in the same way,
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2:05 - 2:07but what's great about ants is
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2:07 - 2:12that you can see the whole network as it happens.
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2:12 - 2:15There are more than 12,000 species of ants,
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2:15 - 2:17in every conceivable environment,
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2:17 - 2:20and they're using interactions differently
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2:20 - 2:22to meet different environmental challenges.
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2:22 - 2:25So one important environmental challenge
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2:25 - 2:27that every system has to deal with
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2:27 - 2:29is operating costs, just what it takes
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2:29 - 2:31to run the system.
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2:31 - 2:33And another environmental challenge is resources,
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2:33 - 2:36finding them and collecting them.
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2:36 - 2:39In the desert, operating costs are high
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2:39 - 2:40because water is scarce,
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2:40 - 2:43and the seed-eating ants that I study in the desert
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2:43 - 2:46have to spend water to get water.
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2:46 - 2:48So an ant outside foraging,
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2:48 - 2:50searching for seeds in the hot sun,
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2:50 - 2:52just loses water into the air.
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2:52 - 2:54But the colony gets its water
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2:54 - 2:55by metabolizing the fats out of the seeds
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2:55 - 2:57that they eat.
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2:57 - 3:00So in this environment, interactions are used
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3:00 - 3:02to activate foraging.
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3:02 - 3:04An outgoing forager doesn't go out unless
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3:04 - 3:07it gets enough interactions with returning foragers,
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3:07 - 3:09and what you see are the returning foragers
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3:09 - 3:11going into the tunnel, into the nest,
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3:11 - 3:13and meeting outgoing foragers on their way out.
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3:13 - 3:15This makes sense for the ant colony,
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3:15 - 3:17because the more food there is out there,
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3:17 - 3:19the more quickly the foragers find it,
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3:19 - 3:20the faster they come back,
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3:20 - 3:23and the more foragers they send out.
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3:23 - 3:26The system works to stay stopped,
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3:26 - 3:28unless something positive happens.
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3:28 - 3:32So interactions function to activate foragers.
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3:32 - 3:34And we've been studying
the evolution of this system. -
3:34 - 3:36First of all, there's variation.
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3:36 - 3:38It turns out that colonies are different.
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3:38 - 3:41On dry days, some colonies forage less,
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3:41 - 3:42so colonies are different in how
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3:42 - 3:44they manage this trade-off
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3:44 - 3:47between spending water to search for seeds
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3:47 - 3:50and getting water back in the form of seeds.
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3:50 - 3:52And we're trying to understand why
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3:52 - 3:54some colonies forage less than others
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3:54 - 3:56by thinking about ants as neurons,
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3:56 - 3:59using models from neuroscience.
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3:59 - 4:01So just as a neuron adds up its stimulation
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4:01 - 4:03from other neurons to decide whether to fire,
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4:03 - 4:06an ant adds up its stimulation from other ants
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4:06 - 4:08to decide whether to forage.
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4:08 - 4:10And what we're looking for is whether there might be
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4:10 - 4:12small differences among colonies
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4:12 - 4:15in how many interactions each ant needs
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4:15 - 4:17before it's willing to go out and forage,
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4:17 - 4:21because a colony like that would forage less.
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4:21 - 4:24And this raises an analogous question about brains.
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4:24 - 4:25We talk about the brain,
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4:25 - 4:28but of course every brain is slightly different,
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4:28 - 4:30and maybe there are some individuals
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4:30 - 4:31or some conditions
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4:31 - 4:34in which the electrical properties of neurons are such
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4:34 - 4:38that they require more stimulus to fire,
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4:38 - 4:42and that would lead to differences in brain function.
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4:42 - 4:44So in order to ask evolutionary questions,
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4:44 - 4:47we need to know about reproductive success.
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4:47 - 4:49This is a map of the study site
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4:49 - 4:52where I have been tracking this population
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4:52 - 4:55of harvester ant colonies for 28 years,
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4:55 - 4:57which is about as long as a colony lives.
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4:57 - 4:59Each symbol is a colony,
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4:59 - 5:03and the size of the symbol is
how many offspring it had, -
5:03 - 5:05because we were able to use genetic variation
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5:05 - 5:07to match up parent and offspring colonies,
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5:07 - 5:11that is, to figure out which colonies
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5:11 - 5:12were founded by a daughter queen
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5:12 - 5:15produced by which parent colony.
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5:15 - 5:17And this was amazing for me, after all these years,
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5:17 - 5:20to find out, for example, that colony 154,
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5:20 - 5:22whom I've known well for many years,
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5:22 - 5:24is a great-grandmother.
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5:24 - 5:25Here's her daughter colony,
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5:25 - 5:28here's her granddaughter colony,
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5:28 - 5:30and these are her great-granddaughter colonies.
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5:30 - 5:32And by doing this, I was able to learn
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5:32 - 5:36that offspring colonies resemble parent colonies
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5:36 - 5:38in their decisions about which days are so hot
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5:38 - 5:40that they don't forage,
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5:40 - 5:41and the offspring of parent colonies
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5:41 - 5:44live so far from each other that the ants never meet,
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5:44 - 5:46so the ants of the offspring colony
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5:46 - 5:49can't be learning this from the parent colony.
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5:49 - 5:50And so our next step is to look
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5:50 - 5:55for the genetic variation
underlying this resemblance. -
5:55 - 5:59So then I was able to ask, okay, who's doing better?
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5:59 - 6:01Over the time of the study,
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6:01 - 6:02and especially in the past 10 years,
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6:02 - 6:06there's been a very severe and deepening drought
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6:06 - 6:08in the Southwestern U.S.,
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6:08 - 6:11and it turns out that the
colonies that conserve water, -
6:11 - 6:15that stay in when it's really hot outside,
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6:15 - 6:18and thus sacrifice getting as much food as possible,
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6:18 - 6:21are the ones more likely to have offspring colonies.
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6:21 - 6:23So all this time, I thought that colony 154
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6:23 - 6:26was a loser, because on really dry days,
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6:26 - 6:28there'd be just this trickle of foraging,
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6:28 - 6:29while the other colonies were out
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6:29 - 6:31foraging, getting lots of food,
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6:31 - 6:34but in fact, colony 154 is a huge success.
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6:34 - 6:36She's a matriarch.
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6:36 - 6:39She's one of the rare great-grandmothers on the site.
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6:39 - 6:42To my knowledge, this is the first time
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6:42 - 6:43that we've been able to track
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6:43 - 6:46the ongoing evolution of collective behavior
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6:46 - 6:48in a natural population of animals
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6:48 - 6:53and find out what's actually working best.
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6:53 - 6:55Now, the Internet uses an algorithm
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6:55 - 6:58to regulate the flow of data
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6:58 - 7:00that's very similar to the one
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7:00 - 7:03that the harvester ants are using to regulate
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7:03 - 7:04the flow of foragers.
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7:04 - 7:08And guess what we call this analogy?
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7:08 - 7:09The anternet is coming.
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7:09 - 7:11(Applause)
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7:11 - 7:14So data doesn't leave the source computer
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7:14 - 7:17unless it gets a signal that there's enough bandwidth
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7:17 - 7:20for it to travel on.
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7:20 - 7:21In the early days of the Internet,
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7:21 - 7:24when operating costs were really high
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7:24 - 7:27and it was really important not to lose any data,
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7:27 - 7:29then the system was set up for interactions
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7:29 - 7:32to activate the flow of data.
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7:32 - 7:35It's interesting that the ants are using an algorithm
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7:35 - 7:38that's so similar to the one that we recently invented,
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7:38 - 7:41but this is only one of a handful of ant algorithms
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7:41 - 7:43that we know about,
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7:43 - 7:46and ants have had 130 million years
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7:46 - 7:48to evolve a lot of good ones,
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7:48 - 7:50and I think it's very likely
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7:50 - 7:52that some of the other 12,000 species
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7:52 - 7:55are going to have interesting algorithms
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7:55 - 7:56for data networks
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7:56 - 7:59that we haven't even thought of yet.
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7:59 - 8:02So what happens when operating costs are low?
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8:02 - 8:03Operating costs are low in the tropics,
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8:03 - 8:06because it's very humid, and it's easy for the ants
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8:06 - 8:08to be outside walking around.
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8:08 - 8:10But the ants are so abundant
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8:10 - 8:12and diverse in the tropics
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8:12 - 8:14that there's a lot of competition.
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8:14 - 8:16Whatever resource one species is using,
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8:16 - 8:20another species is likely to be using that
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8:20 - 8:22at the same time.
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8:22 - 8:25So in this environment, interactions are used
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8:25 - 8:26in the opposite way.
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8:26 - 8:28The system keeps going
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8:28 - 8:29unless something negative happens,
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8:29 - 8:32and one species that I study makes circuits
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8:32 - 8:34in the trees of foraging ants
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8:34 - 8:37going from the nest to a food source and back,
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8:37 - 8:38just round and round,
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8:38 - 8:40unless something negative happens,
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8:40 - 8:41like an interaction
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8:41 - 8:44with ants of another species.
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8:44 - 8:47So here's an example of ant security.
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8:47 - 8:49In the middle, there's an ant
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8:49 - 8:51plugging the nest entrance with its head
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8:51 - 8:54in response to interactions with another species.
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8:54 - 8:56Those are the little ones running around
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8:56 - 8:59with their abdomens up in the air.
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8:59 - 9:01But as soon as the threat is passed,
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9:01 - 9:03the entrance is open again,
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9:03 - 9:05and maybe there are situations
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9:05 - 9:06in computer security
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9:06 - 9:08where operating costs are low enough
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9:08 - 9:12that we could just block access temporarily
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9:12 - 9:14in response to an immediate threat,
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9:14 - 9:16and then open it again,
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9:16 - 9:17instead of trying to build
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9:17 - 9:21a permanent firewall or fortress.
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9:21 - 9:23So another environmental challenge
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9:23 - 9:25that all systems have to deal with
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9:25 - 9:30is resources, finding and collecting them.
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9:30 - 9:32And to do this, ants solve the problem
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9:32 - 9:33of collective search,
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9:33 - 9:35and this is a problem that's of great interest
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9:35 - 9:36right now in robotics,
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9:36 - 9:38because we've understood that,
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9:38 - 9:40rather than sending a single,
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9:40 - 9:43sophisticated, expensive robot out
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9:43 - 9:45to explore another planet
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9:45 - 9:47or to search a burning building,
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9:47 - 9:50that instead, it may be more effective
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9:50 - 9:54to get a group of cheaper robots
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9:54 - 9:57exchanging only minimal information,
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9:57 - 9:59and that's the way that ants do it.
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9:59 - 10:01So the invasive Argentine ant
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10:01 - 10:04makes expandable search networks.
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10:04 - 10:06They're good at dealing with the main problem
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10:06 - 10:07of collective search,
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10:07 - 10:10which is the trade-off between
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10:10 - 10:11searching very thoroughly
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10:11 - 10:13and covering a lot of ground.
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10:13 - 10:14And what they do is,
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10:14 - 10:16when there are many ants in a small space,
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10:16 - 10:19then each one can search very thoroughly
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10:19 - 10:20because there will be another ant nearby
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10:20 - 10:22searching over there,
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10:22 - 10:23but when there are a few ants
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10:23 - 10:25in a large space,
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10:25 - 10:28then they need to stretch out their paths
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10:28 - 10:29to cover more ground.
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10:29 - 10:32I think they use interactions to assess density,
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10:32 - 10:34so when they're really crowded,
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10:34 - 10:35they meet more often,
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10:35 - 10:37and they search more thoroughly.
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10:37 - 10:41Different ant species must use different algorithms,
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10:41 - 10:43because they've evolved to deal with
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10:43 - 10:45different resources,
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10:45 - 10:47and it could be really useful to know about this,
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10:47 - 10:49and so we recently asked ants
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10:49 - 10:51to solve the collective search problem
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10:51 - 10:53in the extreme environment
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10:53 - 10:54of microgravity
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10:54 - 10:56in the International Space Station.
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10:56 - 10:58When I first saw this picture, I thought,
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10:58 - 11:01Oh no, they've mounted the habitat vertically,
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11:01 - 11:03but then I realized that, of course, it doesn't matter.
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11:03 - 11:06So the idea here is that the ants
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11:06 - 11:08are working so hard to hang on
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11:08 - 11:11to the wall or the floor or whatever you call it
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11:11 - 11:14that they're less likely to interact,
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11:14 - 11:15and so the relationship between
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11:15 - 11:17how crowded they are and how often they meet
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11:17 - 11:19would be messed up.
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11:19 - 11:21We're still analyzing the data.
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11:21 - 11:22I don't have the results yet.
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11:22 - 11:24But it would be interesting to know
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11:24 - 11:27how other species solve this problem
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11:27 - 11:29in different environments on Earth,
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11:29 - 11:30and so we're setting up a program
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11:30 - 11:33to encourage kids around the world
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11:33 - 11:35to try this experiment with different species.
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11:35 - 11:37It's very simple.
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11:37 - 11:39It can be done with cheap materials.
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11:39 - 11:42And that way, we could make a global map
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11:42 - 11:45of ant collective search algorithms.
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11:45 - 11:48And I think it's pretty likely that the invasive species,
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11:48 - 11:50the ones that come into our buildings,
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11:50 - 11:52are going to be really good at this,
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11:52 - 11:53because they're in your kitchen
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11:53 - 11:57because they're really good
at finding food and water. -
11:57 - 12:01So the most familiar resource for ants
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12:01 - 12:02is a picnic,
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12:02 - 12:04and this is a clustered resource.
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12:04 - 12:05When there's one piece of fruit,
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12:05 - 12:08there's likely to be another piece of fruit nearby,
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12:08 - 12:11and the ants that specialize on clustered resources
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12:11 - 12:13use interactions for recruitment.
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12:13 - 12:14So when one ant meets another,
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12:14 - 12:16or when it meets a chemical deposited
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12:16 - 12:18on the ground by another,
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12:18 - 12:19then it changes direction to follow
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12:19 - 12:21in the direction of the interaction,
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12:21 - 12:23and that's how you get the trail of ants
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12:23 - 12:24sharing your picnic.
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12:24 - 12:26Now this is a place where I think we might be able
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12:26 - 12:30to learn something from ants about cancer.
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12:30 - 12:32I mean, first, it's obvious that we could do a lot
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12:32 - 12:33to prevent cancer
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12:33 - 12:36by not allowing people to spread around
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12:36 - 12:38or sell the toxins that promote
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12:38 - 12:41the evolution of cancer in our bodies,
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12:41 - 12:43but I don't think the ants can help us much with this
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12:43 - 12:46because ants never poison their own colonies.
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12:46 - 12:48But we might be able to learn something from ants
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12:48 - 12:50about treating cancer.
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12:50 - 12:52There are many different kinds of cancer.
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12:52 - 12:55Each one originates in a particular part of the body,
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12:55 - 12:58and then some kinds of cancer will spread
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12:58 - 13:01or metastasize to particular other tissues
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13:01 - 13:03where they must be getting
resources that they need. -
13:03 - 13:05So if you think from the perspective
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13:05 - 13:07of early metastatic cancer cells
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13:07 - 13:09as they're out searching around
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13:09 - 13:11for the resources that they need,
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13:11 - 13:13if those resources are clustered,
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13:13 - 13:16they're likely to use interactions for recruitment,
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13:16 - 13:19and if we can figure out how
cancer cells are recruiting, -
13:19 - 13:22then maybe we could set traps
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13:22 - 13:26to catch them before they become established.
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13:26 - 13:29So ants are using interactions in different ways
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13:29 - 13:31in a huge variety of environments,
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13:31 - 13:33and we could learn from this
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13:33 - 13:35about other systems that operate
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13:35 - 13:37without central control.
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13:37 - 13:39Using only simple interactions,
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13:39 - 13:41ant colonies have been performing
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13:41 - 13:45amazing feats for more than 130 million years.
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13:45 - 13:47We have a lot to learn from them.
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13:47 - 13:50Thank you.
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13:50 - 13:52(Applause)
- Title:
- What ants teach us about the brain, cancer and the Internet
- Speaker:
- Deborah Gordon
- Description:
-
Ecologist Deborah Gordon studies ants wherever she can find them -- in the desert, in the tropics, in her kitchen ... In this fascinating talk, she explains her obsession with insects most of us would happily swat away without a second thought. She argues that ant life provides a useful model for learning about many other topics, including disease, technology and the human brain.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TEDTalks
- Duration:
- 14:09
Morton Bast edited English subtitles for What ants teach us about the brain, cancer and the Internet | ||
Morton Bast edited English subtitles for What ants teach us about the brain, cancer and the Internet | ||
Morton Bast edited English subtitles for What ants teach us about the brain, cancer and the Internet | ||
Morton Bast edited English subtitles for What ants teach us about the brain, cancer and the Internet | ||
Morton Bast edited English subtitles for What ants teach us about the brain, cancer and the Internet | ||
Morton Bast approved English subtitles for What ants teach us about the brain, cancer and the Internet | ||
Madeleine Aronson edited English subtitles for What ants teach us about the brain, cancer and the Internet | ||
Madeleine Aronson edited English subtitles for What ants teach us about the brain, cancer and the Internet |