[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:03.39,0:00:04.70,Default,,0000,0000,0000,,Science,
Dialogue: 0,0:00:04.70,0:00:07.96,Default,,0000,0000,0000,,science has allowed us to know so much
Dialogue: 0,0:00:07.96,0:00:11.11,Default,,0000,0000,0000,,about the far reaches of the universe,
Dialogue: 0,0:00:11.11,0:00:14.30,Default,,0000,0000,0000,,which is at the same time tremendously important
Dialogue: 0,0:00:14.30,0:00:16.31,Default,,0000,0000,0000,,and extremely remote,
Dialogue: 0,0:00:16.31,0:00:18.83,Default,,0000,0000,0000,,and yet much, much closer,
Dialogue: 0,0:00:18.83,0:00:20.92,Default,,0000,0000,0000,,much more directly related to us.
Dialogue: 0,0:00:20.92,0:00:23.46,Default,,0000,0000,0000,,There are many things we don't really understand.
Dialogue: 0,0:00:23.46,0:00:25.53,Default,,0000,0000,0000,,And one of them is the extraordinary
Dialogue: 0,0:00:25.53,0:00:28.92,Default,,0000,0000,0000,,social complexity of the animals around us,
Dialogue: 0,0:00:28.92,0:00:30.84,Default,,0000,0000,0000,,and today I want to tell you a few stories
Dialogue: 0,0:00:30.84,0:00:32.87,Default,,0000,0000,0000,,of animal complexity.
Dialogue: 0,0:00:32.87,0:00:36.35,Default,,0000,0000,0000,,But first, what do we call complexity?
Dialogue: 0,0:00:36.35,0:00:37.66,Default,,0000,0000,0000,,What is complex?
Dialogue: 0,0:00:37.66,0:00:41.22,Default,,0000,0000,0000,,Well, complex is not complicated.
Dialogue: 0,0:00:41.22,0:00:44.61,Default,,0000,0000,0000,,Something complicated comprises many small parts,
Dialogue: 0,0:00:44.61,0:00:47.00,Default,,0000,0000,0000,,all different, and each of them
Dialogue: 0,0:00:47.00,0:00:50.26,Default,,0000,0000,0000,,has its own precise role in the machinery.
Dialogue: 0,0:00:50.26,0:00:52.92,Default,,0000,0000,0000,,On the opposite, a complex system
Dialogue: 0,0:00:52.92,0:00:55.66,Default,,0000,0000,0000,,is made of many, many similar parts,
Dialogue: 0,0:00:55.66,0:00:57.52,Default,,0000,0000,0000,,and it is their interaction
Dialogue: 0,0:00:57.52,0:01:00.100,Default,,0000,0000,0000,,that produces a globally cohering behavior.
Dialogue: 0,0:01:00.100,0:01:04.76,Default,,0000,0000,0000,,Complex systems have many interacting parts
Dialogue: 0,0:01:04.76,0:01:08.24,Default,,0000,0000,0000,,which behave according to simple, individual rules,
Dialogue: 0,0:01:08.24,0:01:11.56,Default,,0000,0000,0000,,and this results in emergent properties.
Dialogue: 0,0:01:11.56,0:01:13.47,Default,,0000,0000,0000,,The behavior of the system as a whole
Dialogue: 0,0:01:13.47,0:01:15.05,Default,,0000,0000,0000,,cannot be predicted
Dialogue: 0,0:01:15.05,0:01:17.43,Default,,0000,0000,0000,,from the individual rules only.
Dialogue: 0,0:01:17.43,0:01:18.99,Default,,0000,0000,0000,,As Aristotle wrote,
Dialogue: 0,0:01:18.99,0:01:22.22,Default,,0000,0000,0000,,the whole is greater than the sum of its parts.
Dialogue: 0,0:01:22.22,0:01:24.90,Default,,0000,0000,0000,,But from Aristotle, let's move onto a more
Dialogue: 0,0:01:24.90,0:01:28.25,Default,,0000,0000,0000,,concrete example of complex systems.
Dialogue: 0,0:01:28.25,0:01:30.22,Default,,0000,0000,0000,,These are Scottish terriers.
Dialogue: 0,0:01:30.22,0:01:34.05,Default,,0000,0000,0000,,In the beginning, the system is disorganized.
Dialogue: 0,0:01:34.05,0:01:37.86,Default,,0000,0000,0000,,Then comes a perturbation: milk.
Dialogue: 0,0:01:37.86,0:01:41.09,Default,,0000,0000,0000,,Every individual starts pushing in one direction
Dialogue: 0,0:01:41.09,0:01:42.04,Default,,0000,0000,0000,,— (Laughter) —
Dialogue: 0,0:01:42.04,0:01:45.07,Default,,0000,0000,0000,,and this is what happens.
Dialogue: 0,0:01:45.07,0:01:47.71,Default,,0000,0000,0000,,The pinwheel is an emergent property
Dialogue: 0,0:01:47.71,0:01:49.95,Default,,0000,0000,0000,,of the interactions between puppies
Dialogue: 0,0:01:49.95,0:01:53.82,Default,,0000,0000,0000,,whose only rule is to try to keep access to the milk
Dialogue: 0,0:01:53.82,0:01:57.31,Default,,0000,0000,0000,,and therefore to push in a random direction.
Dialogue: 0,0:01:57.31,0:02:01.05,Default,,0000,0000,0000,,So it's all about finding the simple rules
Dialogue: 0,0:02:01.05,0:02:04.11,Default,,0000,0000,0000,,from which complexity emerges.
Dialogue: 0,0:02:04.11,0:02:06.90,Default,,0000,0000,0000,,I call this simplifying complexity,
Dialogue: 0,0:02:06.90,0:02:09.05,Default,,0000,0000,0000,,and it's what we do the Chair of Systems Design
Dialogue: 0,0:02:09.05,0:02:10.96,Default,,0000,0000,0000,,at ETH Zurich.
Dialogue: 0,0:02:10.96,0:02:14.53,Default,,0000,0000,0000,,We collect data on animal populations,
Dialogue: 0,0:02:14.53,0:02:18.37,Default,,0000,0000,0000,,analyze complex patterns, try to explain them.
Dialogue: 0,0:02:18.37,0:02:21.14,Default,,0000,0000,0000,,It requires physicists who work with biologists,
Dialogue: 0,0:02:21.14,0:02:23.96,Default,,0000,0000,0000,,with mathematicians and computer scientists,
Dialogue: 0,0:02:23.96,0:02:26.47,Default,,0000,0000,0000,,and it is their interaction that produces
Dialogue: 0,0:02:26.47,0:02:28.37,Default,,0000,0000,0000,,cross-boundary competence
Dialogue: 0,0:02:28.37,0:02:29.98,Default,,0000,0000,0000,,to solve these problems.
Dialogue: 0,0:02:29.98,0:02:32.20,Default,,0000,0000,0000,,So again, the whole is greater
Dialogue: 0,0:02:32.20,0:02:33.59,Default,,0000,0000,0000,,than the sum of its parts.
Dialogue: 0,0:02:33.59,0:02:35.82,Default,,0000,0000,0000,,In a way, collaboration
Dialogue: 0,0:02:35.82,0:02:39.52,Default,,0000,0000,0000,,is another example of complex systems.
Dialogue: 0,0:02:39.52,0:02:41.15,Default,,0000,0000,0000,,And you may be asking yourself
Dialogue: 0,0:02:41.15,0:02:43.98,Default,,0000,0000,0000,,which side I'm on, biology or physics.
Dialogue: 0,0:02:43.98,0:02:46.29,Default,,0000,0000,0000,,In fact, it's a little different,
Dialogue: 0,0:02:46.29,0:02:47.56,Default,,0000,0000,0000,,and to explain, I need to tell you
Dialogue: 0,0:02:47.56,0:02:50.26,Default,,0000,0000,0000,,a short story about myself.
Dialogue: 0,0:02:50.26,0:02:51.83,Default,,0000,0000,0000,,When I was a child,
Dialogue: 0,0:02:51.83,0:02:55.82,Default,,0000,0000,0000,,I loved to build stuff, to\Ncreate complicated machines.
Dialogue: 0,0:02:55.82,0:02:58.41,Default,,0000,0000,0000,,So I set out to study electrical engineering
Dialogue: 0,0:02:58.41,0:03:00.16,Default,,0000,0000,0000,,and robotics,
Dialogue: 0,0:03:00.16,0:03:02.03,Default,,0000,0000,0000,,and my end-of-studies project
Dialogue: 0,0:03:02.03,0:03:05.00,Default,,0000,0000,0000,,was about building a robot called ER-1
Dialogue: 0,0:03:05.00,0:03:06.90,Default,,0000,0000,0000,,—it looked like this—
Dialogue: 0,0:03:06.90,0:03:09.49,Default,,0000,0000,0000,,that would collect information from its environment
Dialogue: 0,0:03:09.49,0:03:12.97,Default,,0000,0000,0000,,and proceed to follow a white line on the ground.
Dialogue: 0,0:03:12.97,0:03:15.27,Default,,0000,0000,0000,,It was very, very complicated,
Dialogue: 0,0:03:15.27,0:03:18.33,Default,,0000,0000,0000,,but it worked beautifully in our test room,
Dialogue: 0,0:03:18.33,0:03:20.62,Default,,0000,0000,0000,,and on demo day, professors had assembled
Dialogue: 0,0:03:20.62,0:03:21.98,Default,,0000,0000,0000,,to grade to the project.
Dialogue: 0,0:03:21.98,0:03:24.76,Default,,0000,0000,0000,,So we took ER-1 to the evaluation room.
Dialogue: 0,0:03:24.76,0:03:27.08,Default,,0000,0000,0000,,It turned out, the light in that room
Dialogue: 0,0:03:27.08,0:03:28.82,Default,,0000,0000,0000,,was slightly different.
Dialogue: 0,0:03:28.82,0:03:31.12,Default,,0000,0000,0000,,The robot's vision system got confused.
Dialogue: 0,0:03:31.12,0:03:32.87,Default,,0000,0000,0000,,At the first bend in the line,
Dialogue: 0,0:03:32.87,0:03:36.53,Default,,0000,0000,0000,,it left its course, and crashed into a wall.
Dialogue: 0,0:03:36.53,0:03:38.70,Default,,0000,0000,0000,,We had spent weeks building it,
Dialogue: 0,0:03:38.70,0:03:40.34,Default,,0000,0000,0000,,and all it took to destroy it
Dialogue: 0,0:03:40.34,0:03:42.95,Default,,0000,0000,0000,,was a subtle change in the color of the light
Dialogue: 0,0:03:42.95,0:03:44.64,Default,,0000,0000,0000,,in the room.
Dialogue: 0,0:03:44.64,0:03:46.08,Default,,0000,0000,0000,,That's when I realized that
Dialogue: 0,0:03:46.08,0:03:48.20,Default,,0000,0000,0000,,the more complicated you make a machine,
Dialogue: 0,0:03:48.20,0:03:50.44,Default,,0000,0000,0000,,the more likely that it will fail
Dialogue: 0,0:03:50.44,0:03:53.09,Default,,0000,0000,0000,,due to something absolutely unexpected.
Dialogue: 0,0:03:53.09,0:03:54.76,Default,,0000,0000,0000,,And I decided that, in fact,
Dialogue: 0,0:03:54.76,0:03:57.77,Default,,0000,0000,0000,,I didn't really want to create complicated stuff.
Dialogue: 0,0:03:57.77,0:04:00.71,Default,,0000,0000,0000,,I wanted to understand complexity,
Dialogue: 0,0:04:00.71,0:04:02.70,Default,,0000,0000,0000,,complexity of the world around us
Dialogue: 0,0:04:02.70,0:04:05.40,Default,,0000,0000,0000,,and especially in the animal kingdom.
Dialogue: 0,0:04:05.40,0:04:08.29,Default,,0000,0000,0000,,Which brings us to bats.
Dialogue: 0,0:04:08.29,0:04:11.63,Default,,0000,0000,0000,,Bechstein's bats are a common\Nspecies of European bats.
Dialogue: 0,0:04:11.63,0:04:13.04,Default,,0000,0000,0000,,They are very social animals.
Dialogue: 0,0:04:13.04,0:04:15.43,Default,,0000,0000,0000,,Mostly they roost or sleep together.
Dialogue: 0,0:04:15.43,0:04:17.100,Default,,0000,0000,0000,,And they live in maternity colonies,
Dialogue: 0,0:04:17.100,0:04:19.58,Default,,0000,0000,0000,,which means that every spring,
Dialogue: 0,0:04:19.58,0:04:22.66,Default,,0000,0000,0000,,the females meet after the winter hybernation,
Dialogue: 0,0:04:22.66,0:04:24.91,Default,,0000,0000,0000,,and they stay together for about six months
Dialogue: 0,0:04:24.91,0:04:26.94,Default,,0000,0000,0000,,to rear their young,
Dialogue: 0,0:04:26.94,0:04:30.08,Default,,0000,0000,0000,,and they all carry a very small chip,
Dialogue: 0,0:04:30.08,0:04:31.84,Default,,0000,0000,0000,,which means that every time one of them
Dialogue: 0,0:04:31.84,0:04:35.16,Default,,0000,0000,0000,,enters one of these specially equipped bat boxes,
Dialogue: 0,0:04:35.16,0:04:36.81,Default,,0000,0000,0000,,we know where she is,
Dialogue: 0,0:04:36.81,0:04:38.09,Default,,0000,0000,0000,,and more importantly,
Dialogue: 0,0:04:38.09,0:04:40.51,Default,,0000,0000,0000,,we know with whom she is.
Dialogue: 0,0:04:40.51,0:04:44.19,Default,,0000,0000,0000,,So I study roosting associations in bats,
Dialogue: 0,0:04:44.19,0:04:46.83,Default,,0000,0000,0000,,and this is what it looks like.
Dialogue: 0,0:04:46.83,0:04:48.92,Default,,0000,0000,0000,,During the day, the bats roost
Dialogue: 0,0:04:48.92,0:04:51.52,Default,,0000,0000,0000,,in a number of sub-groups in different boxes.
Dialogue: 0,0:04:51.52,0:04:53.06,Default,,0000,0000,0000,,It could be that on one day,
Dialogue: 0,0:04:53.06,0:04:55.24,Default,,0000,0000,0000,,the colony is split between two boxes,
Dialogue: 0,0:04:55.24,0:04:56.93,Default,,0000,0000,0000,,but on another day,
Dialogue: 0,0:04:56.93,0:04:59.25,Default,,0000,0000,0000,,it could be together in a single box,
Dialogue: 0,0:04:59.25,0:05:01.40,Default,,0000,0000,0000,,or split between three or more boxes,
Dialogue: 0,0:05:01.40,0:05:04.45,Default,,0000,0000,0000,,and that all seems rather erratic, really.
Dialogue: 0,0:05:04.45,0:05:07.53,Default,,0000,0000,0000,,It's called fission-fusion dynamics,
Dialogue: 0,0:05:07.53,0:05:09.24,Default,,0000,0000,0000,,the property for an animal group
Dialogue: 0,0:05:09.24,0:05:11.48,Default,,0000,0000,0000,,of regularly splitting and merging
Dialogue: 0,0:05:11.48,0:05:13.20,Default,,0000,0000,0000,,into different subgroups.
Dialogue: 0,0:05:13.20,0:05:15.69,Default,,0000,0000,0000,,So what we do is take all these data
Dialogue: 0,0:05:15.69,0:05:17.32,Default,,0000,0000,0000,,from all these different days
Dialogue: 0,0:05:17.32,0:05:18.84,Default,,0000,0000,0000,,and pool them together
Dialogue: 0,0:05:18.84,0:05:21.44,Default,,0000,0000,0000,,to extract a long-term association pattern
Dialogue: 0,0:05:21.44,0:05:23.82,Default,,0000,0000,0000,,by playing techniques with network analysis
Dialogue: 0,0:05:23.82,0:05:25.52,Default,,0000,0000,0000,,to get a complete picture
Dialogue: 0,0:05:25.52,0:05:28.07,Default,,0000,0000,0000,,of the social structure of the colony.
Dialogue: 0,0:05:28.07,0:05:32.26,Default,,0000,0000,0000,,Okay? So that's what this picture looks like.
Dialogue: 0,0:05:32.26,0:05:34.83,Default,,0000,0000,0000,,In this network, all the circles
Dialogue: 0,0:05:34.83,0:05:37.20,Default,,0000,0000,0000,,are nodes, individual bats,
Dialogue: 0,0:05:37.20,0:05:38.94,Default,,0000,0000,0000,,and the lines between them
Dialogue: 0,0:05:38.94,0:05:42.70,Default,,0000,0000,0000,,are social bonds, associations between individuals.
Dialogue: 0,0:05:42.70,0:05:45.37,Default,,0000,0000,0000,,It turns out this is a very interesting picture.
Dialogue: 0,0:05:45.37,0:05:47.48,Default,,0000,0000,0000,,This bat colony is organized
Dialogue: 0,0:05:47.48,0:05:49.25,Default,,0000,0000,0000,,in two different communities
Dialogue: 0,0:05:49.25,0:05:51.05,Default,,0000,0000,0000,,which cannot be predicted
Dialogue: 0,0:05:51.05,0:05:53.37,Default,,0000,0000,0000,,from the daily fission-future dynamics.
Dialogue: 0,0:05:53.37,0:05:57.00,Default,,0000,0000,0000,,We call them cryptic social units.
Dialogue: 0,0:05:57.00,0:05:58.62,Default,,0000,0000,0000,,Even more interesting, in fact:
Dialogue: 0,0:05:58.62,0:06:00.84,Default,,0000,0000,0000,,every year, around October,
Dialogue: 0,0:06:00.84,0:06:02.49,Default,,0000,0000,0000,,the colony splits up,
Dialogue: 0,0:06:02.49,0:06:05.05,Default,,0000,0000,0000,,and all bats hibernate separately,
Dialogue: 0,0:06:05.05,0:06:06.68,Default,,0000,0000,0000,,but year after year,
Dialogue: 0,0:06:06.68,0:06:09.57,Default,,0000,0000,0000,,when the bats come together again in the spring,
Dialogue: 0,0:06:09.57,0:06:12.39,Default,,0000,0000,0000,,the communities stay the same.
Dialogue: 0,0:06:12.39,0:06:14.85,Default,,0000,0000,0000,,So these bats remember their friends
Dialogue: 0,0:06:14.85,0:06:16.93,Default,,0000,0000,0000,,for a really long time.
Dialogue: 0,0:06:16.93,0:06:19.03,Default,,0000,0000,0000,,With a brain the size of a peanut,
Dialogue: 0,0:06:19.03,0:06:21.22,Default,,0000,0000,0000,,they maintain individualized,
Dialogue: 0,0:06:21.22,0:06:23.55,Default,,0000,0000,0000,,long-term social bonds,
Dialogue: 0,0:06:23.55,0:06:25.50,Default,,0000,0000,0000,,We didn't know that was possible.
Dialogue: 0,0:06:25.50,0:06:26.81,Default,,0000,0000,0000,,We knew that primates
Dialogue: 0,0:06:26.81,0:06:29.38,Default,,0000,0000,0000,,and elephants and dolphins could do that,
Dialogue: 0,0:06:29.38,0:06:32.20,Default,,0000,0000,0000,,but compared to bats, they have huge brains.
Dialogue: 0,0:06:32.20,0:06:34.47,Default,,0000,0000,0000,,So how could it be
Dialogue: 0,0:06:34.47,0:06:36.76,Default,,0000,0000,0000,,that the bats maintain this complex,
Dialogue: 0,0:06:36.76,0:06:38.34,Default,,0000,0000,0000,,stable social structure
Dialogue: 0,0:06:38.34,0:06:41.84,Default,,0000,0000,0000,,with such limited cognitive abilities?
Dialogue: 0,0:06:41.84,0:06:44.59,Default,,0000,0000,0000,,And this is where complexity brings an answer.
Dialogue: 0,0:06:44.59,0:06:46.38,Default,,0000,0000,0000,,To understand this system,
Dialogue: 0,0:06:46.38,0:06:49.50,Default,,0000,0000,0000,,we built a computer model of roosting,
Dialogue: 0,0:06:49.50,0:06:51.52,Default,,0000,0000,0000,,based on simple, individual rules,
Dialogue: 0,0:06:51.52,0:06:54.05,Default,,0000,0000,0000,,and simulated thousands and thousands of days
Dialogue: 0,0:06:54.05,0:06:55.96,Default,,0000,0000,0000,,in the virtual bat colony.
Dialogue: 0,0:06:55.96,0:06:57.71,Default,,0000,0000,0000,,It's a mathematical model,
Dialogue: 0,0:06:57.71,0:07:00.28,Default,,0000,0000,0000,,but it's not complicated.
Dialogue: 0,0:07:00.28,0:07:02.90,Default,,0000,0000,0000,,What the model told us is that, in a nutshell,
Dialogue: 0,0:07:02.90,0:07:06.41,Default,,0000,0000,0000,,each bat knows a few other colony members
Dialogue: 0,0:07:06.41,0:07:09.21,Default,,0000,0000,0000,,as her friends, and is just slightly more likely
Dialogue: 0,0:07:09.21,0:07:11.53,Default,,0000,0000,0000,,to roost in a box with them.
Dialogue: 0,0:07:11.53,0:07:13.93,Default,,0000,0000,0000,,Simple, individual rules.
Dialogue: 0,0:07:13.93,0:07:15.61,Default,,0000,0000,0000,,This is all it takes to explain
Dialogue: 0,0:07:15.61,0:07:18.22,Default,,0000,0000,0000,,the social complexity of these bats.
Dialogue: 0,0:07:18.22,0:07:19.95,Default,,0000,0000,0000,,But it gets better.
Dialogue: 0,0:07:19.95,0:07:22.35,Default,,0000,0000,0000,,Between 2010 and 2011,
Dialogue: 0,0:07:22.35,0:07:26.01,Default,,0000,0000,0000,,the colony lost more than two thirds of its members,
Dialogue: 0,0:07:26.01,0:07:28.88,Default,,0000,0000,0000,,probably due to the very cold winter.
Dialogue: 0,0:07:28.88,0:07:32.10,Default,,0000,0000,0000,,The next spring, it didn't form two communities
Dialogue: 0,0:07:32.10,0:07:33.82,Default,,0000,0000,0000,,like every year,
Dialogue: 0,0:07:33.82,0:07:35.65,Default,,0000,0000,0000,,which may have led the whole colony to die
Dialogue: 0,0:07:35.65,0:07:37.82,Default,,0000,0000,0000,,because it had become too small.
Dialogue: 0,0:07:37.82,0:07:42.95,Default,,0000,0000,0000,,Instead, it formed a single, cohesive social unit,
Dialogue: 0,0:07:42.95,0:07:45.87,Default,,0000,0000,0000,,which allowed the colony to survive that season
Dialogue: 0,0:07:45.87,0:07:49.19,Default,,0000,0000,0000,,and thrive again in the next two years.
Dialogue: 0,0:07:49.19,0:07:50.80,Default,,0000,0000,0000,,What we know is that the bats
Dialogue: 0,0:07:50.80,0:07:53.66,Default,,0000,0000,0000,,are not aware that their colony is doing this.
Dialogue: 0,0:07:53.66,0:07:57.05,Default,,0000,0000,0000,,All they do is follow simple association rules,
Dialogue: 0,0:07:57.05,0:07:58.66,Default,,0000,0000,0000,,and from this simplicity
Dialogue: 0,0:07:58.66,0:08:00.96,Default,,0000,0000,0000,,emerges social complexity
Dialogue: 0,0:08:00.96,0:08:03.76,Default,,0000,0000,0000,,which allows the colony to be resilient
Dialogue: 0,0:08:03.76,0:08:07.04,Default,,0000,0000,0000,,against dramatic changes\Nin the population structure.
Dialogue: 0,0:08:07.04,0:08:09.71,Default,,0000,0000,0000,,And I find this incredible.
Dialogue: 0,0:08:09.71,0:08:11.53,Default,,0000,0000,0000,,Now I want to tell you another story,
Dialogue: 0,0:08:11.53,0:08:13.21,Default,,0000,0000,0000,,but from this we have to travel from Europe
Dialogue: 0,0:08:13.21,0:08:16.30,Default,,0000,0000,0000,,to the Kalahari Desert in South Africa.
Dialogue: 0,0:08:16.30,0:08:18.22,Default,,0000,0000,0000,,This is where meerkats live.
Dialogue: 0,0:08:18.22,0:08:19.80,Default,,0000,0000,0000,,I'm sure you know meerkats.
Dialogue: 0,0:08:19.80,0:08:21.40,Default,,0000,0000,0000,,They're fascinating creatures.
Dialogue: 0,0:08:21.40,0:08:24.82,Default,,0000,0000,0000,,They live in groups with a\Nvery strict social hierarchy.
Dialogue: 0,0:08:24.82,0:08:26.31,Default,,0000,0000,0000,,There is one dominant pair,
Dialogue: 0,0:08:26.31,0:08:27.60,Default,,0000,0000,0000,,and many subordinates,
Dialogue: 0,0:08:27.60,0:08:29.42,Default,,0000,0000,0000,,some acting as sentinels,
Dialogue: 0,0:08:29.42,0:08:30.72,Default,,0000,0000,0000,,some acting as babysitters,
Dialogue: 0,0:08:30.72,0:08:32.56,Default,,0000,0000,0000,,some teaching pups, and so on.
Dialogue: 0,0:08:32.56,0:08:35.85,Default,,0000,0000,0000,,What we do is put very small GPS collars
Dialogue: 0,0:08:35.85,0:08:37.58,Default,,0000,0000,0000,,on these animals
Dialogue: 0,0:08:37.58,0:08:39.45,Default,,0000,0000,0000,,to study how they move together,
Dialogue: 0,0:08:39.45,0:08:42.100,Default,,0000,0000,0000,,and what this has to do with their social structure.
Dialogue: 0,0:08:42.100,0:08:44.56,Default,,0000,0000,0000,,And there's a very interesting example
Dialogue: 0,0:08:44.56,0:08:47.13,Default,,0000,0000,0000,,of collective movement in meerkats.
Dialogue: 0,0:08:47.13,0:08:49.57,Default,,0000,0000,0000,,In the middle of the reserve which they live in
Dialogue: 0,0:08:49.57,0:08:50.80,Default,,0000,0000,0000,,lies a road.
Dialogue: 0,0:08:50.80,0:08:54.14,Default,,0000,0000,0000,,On this road there are cars, so it's dangerous.
Dialogue: 0,0:08:54.14,0:08:56.06,Default,,0000,0000,0000,,But the meerkats have to cross it
Dialogue: 0,0:08:56.06,0:08:58.79,Default,,0000,0000,0000,,to get from one feeding place to another.
Dialogue: 0,0:08:58.79,0:09:03.53,Default,,0000,0000,0000,,So we asked, how exactly do they do this?
Dialogue: 0,0:09:03.53,0:09:05.49,Default,,0000,0000,0000,,We found that the dominant female
Dialogue: 0,0:09:05.49,0:09:08.11,Default,,0000,0000,0000,,is mostly the one who leads the group to the road,
Dialogue: 0,0:09:08.11,0:09:11.17,Default,,0000,0000,0000,,but when it comes to crossing it, crossing the road,
Dialogue: 0,0:09:11.17,0:09:13.61,Default,,0000,0000,0000,,she gives way to the subordinates,
Dialogue: 0,0:09:13.61,0:09:15.07,Default,,0000,0000,0000,,a manner of saying, you know,
Dialogue: 0,0:09:15.07,0:09:18.64,Default,,0000,0000,0000,,"Go ahead, tell me if it's safe."
Dialogue: 0,0:09:18.64,0:09:19.96,Default,,0000,0000,0000,,But what I didn't know, in fact,
Dialogue: 0,0:09:19.96,0:09:22.69,Default,,0000,0000,0000,,was what rules in their behavior the meerkats follow
Dialogue: 0,0:09:22.69,0:09:25.62,Default,,0000,0000,0000,,for this change at the edge of the group to happen
Dialogue: 0,0:09:25.62,0:09:29.86,Default,,0000,0000,0000,,and if simple rules were sufficient to explain it.
Dialogue: 0,0:09:29.86,0:09:33.50,Default,,0000,0000,0000,,So I built a model, a model of simulating meerkats
Dialogue: 0,0:09:33.50,0:09:35.88,Default,,0000,0000,0000,,crossing a simulated road.
Dialogue: 0,0:09:35.88,0:09:37.69,Default,,0000,0000,0000,,It's a simplistic model.
Dialogue: 0,0:09:37.69,0:09:40.39,Default,,0000,0000,0000,,Moving meerkats are like random particles
Dialogue: 0,0:09:40.39,0:09:42.67,Default,,0000,0000,0000,,whose unique rule is one of alignment.
Dialogue: 0,0:09:42.67,0:09:45.17,Default,,0000,0000,0000,,They simply move together.
Dialogue: 0,0:09:45.17,0:09:47.97,Default,,0000,0000,0000,,When these particles get to the road,
Dialogue: 0,0:09:47.97,0:09:50.02,Default,,0000,0000,0000,,they sense some kind of obstacle,
Dialogue: 0,0:09:50.02,0:09:52.30,Default,,0000,0000,0000,,and they bounce against it.
Dialogue: 0,0:09:52.30,0:09:53.38,Default,,0000,0000,0000,,The only difference
Dialogue: 0,0:09:53.38,0:09:55.44,Default,,0000,0000,0000,,between the dominant female, here in red,
Dialogue: 0,0:09:55.44,0:09:56.92,Default,,0000,0000,0000,,and the other individuals,
Dialogue: 0,0:09:56.92,0:09:59.56,Default,,0000,0000,0000,,is that for her, the height of the obstacle,
Dialogue: 0,0:09:59.56,0:10:01.100,Default,,0000,0000,0000,,which is in fact the risk perceived from the road,
Dialogue: 0,0:10:01.100,0:10:03.98,Default,,0000,0000,0000,,is just slightly higher,
Dialogue: 0,0:10:03.98,0:10:05.72,Default,,0000,0000,0000,,and this tiny difference
Dialogue: 0,0:10:05.72,0:10:07.40,Default,,0000,0000,0000,,in the individual's rule of movement
Dialogue: 0,0:10:07.40,0:10:09.77,Default,,0000,0000,0000,,is sufficient to explain what we observe,
Dialogue: 0,0:10:09.77,0:10:12.50,Default,,0000,0000,0000,,that the dominant female
Dialogue: 0,0:10:12.50,0:10:13.100,Default,,0000,0000,0000,,leads her group to the road
Dialogue: 0,0:10:13.100,0:10:15.56,Default,,0000,0000,0000,,and then gives way to the others
Dialogue: 0,0:10:15.56,0:10:18.24,Default,,0000,0000,0000,,for them to cross first.
Dialogue: 0,0:10:18.24,0:10:21.89,Default,,0000,0000,0000,,George Box, who was an English statistician,
Dialogue: 0,0:10:21.89,0:10:24.85,Default,,0000,0000,0000,,once wrote, "All models are false,
Dialogue: 0,0:10:24.85,0:10:27.05,Default,,0000,0000,0000,,but some models are useful."
Dialogue: 0,0:10:27.05,0:10:30.17,Default,,0000,0000,0000,,And in fact, this model is obviously false,
Dialogue: 0,0:10:30.17,0:10:34.32,Default,,0000,0000,0000,,because in reality, meerkats are\Nanything but random particles.
Dialogue: 0,0:10:34.32,0:10:35.86,Default,,0000,0000,0000,,But it's also useful,
Dialogue: 0,0:10:35.86,0:10:38.69,Default,,0000,0000,0000,,because it tells us that extreme simplicity
Dialogue: 0,0:10:38.69,0:10:41.68,Default,,0000,0000,0000,,in movement rules at the individual level
Dialogue: 0,0:10:41.68,0:10:44.17,Default,,0000,0000,0000,,can result in a great deal of complexity
Dialogue: 0,0:10:44.17,0:10:46.37,Default,,0000,0000,0000,,at the level of the group.
Dialogue: 0,0:10:46.37,0:10:50.49,Default,,0000,0000,0000,,So again, that's simplifying complexity.
Dialogue: 0,0:10:50.49,0:10:51.67,Default,,0000,0000,0000,,Now, I would like to conclude
Dialogue: 0,0:10:51.67,0:10:54.21,Default,,0000,0000,0000,,on what this means for the whole species.
Dialogue: 0,0:10:54.21,0:10:55.97,Default,,0000,0000,0000,,When the dominant female
Dialogue: 0,0:10:55.97,0:10:57.75,Default,,0000,0000,0000,,gives way to a subordinate,
Dialogue: 0,0:10:57.75,0:11:00.08,Default,,0000,0000,0000,,it's not out of courtesy.
Dialogue: 0,0:11:00.08,0:11:01.36,Default,,0000,0000,0000,,In fact, the dominant female
Dialogue: 0,0:11:01.36,0:11:04.29,Default,,0000,0000,0000,,is extremely important for the cohesion of the group.
Dialogue: 0,0:11:04.29,0:11:07.50,Default,,0000,0000,0000,,If she dies on the road, the whole group is at risk.
Dialogue: 0,0:11:07.50,0:11:09.78,Default,,0000,0000,0000,,So this behavior of risk avoidance
Dialogue: 0,0:11:09.78,0:11:12.41,Default,,0000,0000,0000,,is a very old evolutionary response.
Dialogue: 0,0:11:12.41,0:11:16.37,Default,,0000,0000,0000,,These meerkats are replicating an evolved tactic
Dialogue: 0,0:11:16.37,0:11:18.56,Default,,0000,0000,0000,,that is thousands of generations old,
Dialogue: 0,0:11:18.56,0:11:20.85,Default,,0000,0000,0000,,and they're adapting it to a modern risk,
Dialogue: 0,0:11:20.85,0:11:24.24,Default,,0000,0000,0000,,in this case a road built by humans.
Dialogue: 0,0:11:24.24,0:11:26.72,Default,,0000,0000,0000,,They adapt very simple rules,
Dialogue: 0,0:11:26.72,0:11:28.97,Default,,0000,0000,0000,,and the resulting complex behavior
Dialogue: 0,0:11:28.97,0:11:31.88,Default,,0000,0000,0000,,allows them to resist human encroachment
Dialogue: 0,0:11:31.88,0:11:34.65,Default,,0000,0000,0000,,into their natural habitat.
Dialogue: 0,0:11:34.65,0:11:36.26,Default,,0000,0000,0000,,In the end,
Dialogue: 0,0:11:36.26,0:11:38.89,Default,,0000,0000,0000,,it may be bats which change their social structure
Dialogue: 0,0:11:38.89,0:11:41.04,Default,,0000,0000,0000,,in response to a population crush,
Dialogue: 0,0:11:41.04,0:11:42.78,Default,,0000,0000,0000,,or it may be meerkats
Dialogue: 0,0:11:42.78,0:11:45.67,Default,,0000,0000,0000,,who show a novel adaptation to a human road,
Dialogue: 0,0:11:45.67,0:11:48.22,Default,,0000,0000,0000,,or it may be another species.
Dialogue: 0,0:11:48.22,0:11:51.30,Default,,0000,0000,0000,,My message here, and it's not a complicated one
Dialogue: 0,0:11:51.30,0:11:54.21,Default,,0000,0000,0000,,but a simple one of wonder and hope,
Dialogue: 0,0:11:54.21,0:11:57.05,Default,,0000,0000,0000,,my message here is that animals
Dialogue: 0,0:11:57.05,0:11:59.75,Default,,0000,0000,0000,,show extraordinary social complexity,
Dialogue: 0,0:11:59.75,0:12:02.15,Default,,0000,0000,0000,,and this allows them to adapt
Dialogue: 0,0:12:02.15,0:12:05.62,Default,,0000,0000,0000,,and respond to changes in their environment.
Dialogue: 0,0:12:05.62,0:12:08.34,Default,,0000,0000,0000,,In three words, in the animal kingdom,
Dialogue: 0,0:12:08.34,0:12:11.23,Default,,0000,0000,0000,,simplicity leads to complexity
Dialogue: 0,0:12:11.23,0:12:12.90,Default,,0000,0000,0000,,which leads to resilience.
Dialogue: 0,0:12:12.90,0:12:14.75,Default,,0000,0000,0000,,Thank you.
Dialogue: 0,0:12:14.75,0:12:21.43,Default,,0000,0000,0000,,(Applause)