Science, science has allowed us to know so much about the far reaches of the universe, which is at the same time tremendously important and extremely remote, and yet much, much closer, much more directly related to us, there are many things we don't really understand. And one of them is the extraordinary social complexity of the animals around us, and today I want to tell you a few stories of animal complexity.
Nauka, nauka nam je omogućila da toliko saznamo o granicama univerzuma, što je ujedno izuzetno važno i veoma daleko, a s druge strane mnogo, mnogo bliže, mnogo više direktno povezano sa nama da mnoge stvari ne razumemo u potpunosti. I jedna od njih je zapanjujuća društvena kompleksnost životinja koje nas okružuju, i danas želim da vam ispričam nekoiko priča u vezi sa životinjskom kompleksnošću.
But first, what do we call complexity? What is complex? Well, complex is not complicated. Something complicated comprises many small parts, all different, and each of them has its own precise role in the machinery. On the opposite, a complex system is made of many, many similar parts, and it is their interaction that produces a globally coherent behavior. Complex systems have many interacting parts which behave according to simple, individual rules, and this results in emergent properties. The behavior of the system as a whole cannot be predicted from the individual rules only. As Aristotle wrote, the whole is greater than the sum of its parts. But from Aristotle, let's move onto a more concrete example of complex systems.
Ali prvo, šta je to kompleksnost? Šta je kompleks? Kompleks nije komplikovanost. Nešto komplikovano je sačinjeno od više manjih delova, različitih, a svaki od njih ima tačno utvrđenu ulogu u mašineriji. Sa druge strane, kompleksan sistem je sačinjen od velikog broja sličnih delova, i njihova međusobna interakcija je ta koja proizvodi celokupno koherentno ponašanje. Kompleksni sistemi imaju mnogo interaktivnih delova koji se ponašaju u skladu sa jednostavnim, pojedinačnim pravilima, a to rezultira pojavom sistemskih svojstava. Ponašanje sistema kao celine ne može se predvideti posmatranjem pojedinačnih pravila. Kao što je Aristotel napisao, "celina je veća od zbira njenih sastavnih delova". Sa Aristotela ćemo preći na konkretniji primer kompleksnog sistema.
These are Scottish terriers. In the beginning, the system is disorganized. Then comes a perturbation: milk. Every individual starts pushing in one direction and this is what happens. The pinwheel is an emergent property of the interactions between puppies whose only rule is to try to keep access to the milk and therefore to push in a random direction.
Ovo su škotski terijeri. Na početku sistem je neorganizovan, Onda dolazi do zbrke: mleko. Svako od njih počinje da gura u jednom pravcu i evo šta se dešava. Vetrenjača je sistemsko svojstvo uzajamnog delovanja štenaca čije je jedino pravilo da zadrže pristup mleku i zato guraju u nasumičnom pravcu.
So it's all about finding the simple rules from which complexity emerges. I call this simplifying complexity, and it's what we do at the chair of systems design at ETH Zurich. We collect data on animal populations, analyze complex patterns, try to explain them. It requires physicists who work with biologists, with mathematicians and computer scientists, and it is their interaction that produces cross-boundary competence to solve these problems. So again, the whole is greater than the sum of the parts. In a way, collaboration is another example of a complex system.
Radi se o nalaženju jednostavnih pravila iz kojih kompleksnost proizilazi. Ja ovo zovem uprošćavanjem složenosti, i to je ono što mi na čelu projektovanja sistema radimo na ETH univerzitetu u Cirihu. Skupljamo podatke o životinjskoj populaciji, analiziramo kompleksne obrasce, pokušavamo da ih objasnimo. Potrebni su fizičari koji rade sa biolozima, sa matematičarima i kompjuterskim naučnicima, i njihova interakcija proizvodi međugraničnu kompetenciju za rešavanje ovih problema. Još jednom, celina je veća od zbira njenih sastavnih delova. Na neki način, saradnja je još jedan primer kompleksnog sistema.
And you may be asking yourself which side I'm on, biology or physics? In fact, it's a little different, and to explain, I need to tell you a short story about myself. When I was a child, I loved to build stuff, to create complicated machines. So I set out to study electrical engineering and robotics, and my end-of-studies project was about building a robot called ER-1 -- it looked like this— that would collect information from its environment and proceed to follow a white line on the ground. It was very, very complicated, but it worked beautifully in our test room, and on demo day, professors had assembled to grade the project. So we took ER-1 to the evaluation room. It turned out, the light in that room was slightly different. The robot's vision system got confused. At the first bend in the line, it left its course, and crashed into a wall. We had spent weeks building it, and all it took to destroy it was a subtle change in the color of the light in the room. That's when I realized that the more complicated you make a machine, the more likely that it will fail due to something absolutely unexpected. And I decided that, in fact, I didn't really want to create complicated stuff. I wanted to understand complexity, the complexity of the world around us and especially in the animal kingdom.
Možda ćete se zapitati na čijoj sam strani, biologa ili fizičara? Zapravo, malo je drugačije, i da bih objasnio moraću da vam ispričam kratku priču o sebi. Kad sam bio dete, voleo sam da gradim stvari, da pravim složene mašine. Te sam otišao da studiram električno inženjerstvo i robotiku, i moj projekat na kraju studija je bio pravljenje robota nazvanog ER-1 koji je izgledao ovako koji bi sakupljao informacije iz svog okruženja i koji bi pratio belu liniju na zemlji. Bio je vrlo, vrlo složen, ali je odlično radio u našoj sobi za testiranje, i na dan prezentovanja, profesori su se okupili da ocene projekat, Odneli smo ER-1 u sobu za procenu. Ispostavilo se da je svetlo u toj sobi malo drugačije. Robotov vidni sistem se poremetio. Pri prvom savijanju na liniji, skrenuo je s puta i zakucao se u zid. Proveli smo nedelje praveći ga, i sve što je bilo potrebno da ga uništi je neznatna promena u boji svetla u sobi. Upravo tada sam shvatio da što složeniju mašinu napraviš, veća je šansa da neće uspeti zbog nečeg sasvim neočekivanog. I odlučio sam, da zapravo, nisam želeo da pravim komplikovane stvari. Želeo sam da razumem kompleksnost, kompleksnost sveta oko nas, a posebno u životinjskom carstvu.
Which brings us to bats. Bechstein's bats are a common species of European bats. They are very social animals. Mostly they roost, or sleep, together. And they live in maternity colonies, which means that every spring, the females meet after the winter hibernation, and they stay together for about six months to rear their young, and they all carry a very small chip, which means that every time one of them enters one of these specially equipped bat boxes, we know where she is, and more importantly, we know with whom she is. So I study roosting associations in bats, and this is what it looks like. During the day, the bats roost in a number of sub-groups in different boxes. It could be that on one day, the colony is split between two boxes, but on another day, it could be together in a single box, or split between three or more boxes, and that all seems rather erratic, really. It's called fission-fusion dynamics, the property for an animal group of regularly splitting and merging into different subgroups.
Što nas dovodi do slepih miševa. Bahtinov slepi miš je česta vrsta u Evropi. Oni su vrlo društvene životinje. Obično se gnezde i spavaju zajedno. I žive u materinskoj koloniji, što znači da svakog proleća, ženke se sastaju nakon zimske hibernacije i ostaju zajedno oko 6 meseci da odgajaju mlade, i sve one nose vrlo mali čip, što znači da kad god jedna od njih uđe u jednu od ovih specijalno opremljenih kutija znamo gde je, i što je važnije, znamo s kim je. Ja proučavam zajednice koje se gnezde zajedno, i to izgleda ovako. Tokom dana slepi miševi se gnezde u mnogobrojnim podgrupama u različitim kutijama. Može se desiti da je jednog dana kolonija podeljena u dve kutije, ali drugog dana su možda zajedno u jednoj kutiji, ili su raspoređeni u 3 ili više kutija, i sve to izgleda prilično haotično. To se zove dinamika fizije i fuzije, svojstvo grupe životinja koje se često razdvajaju i sastavljaju u različite podgrupe.
So what we do is take all these data from all these different days and pool them together to extract a long-term association pattern by applying techniques with network analysis to get a complete picture of the social structure of the colony. Okay? So that's what this picture looks like. In this network, all the circles are nodes, individual bats, and the lines between them are social bonds, associations between individuals. It turns out this is a very interesting picture. This bat colony is organized in two different communities which cannot be predicted from the daily fission-fusion dynamics. We call them cryptic social units. Even more interesting, in fact: Every year, around October, the colony splits up, and all bats hibernate separately, but year after year, when the bats come together again in the spring, the communities stay the same.
Mi sakupimo ove podatke iz svih ovih različitih dana i spojimo ih da bismo izvukli dugoročne šablone povezivanja primenjujući tehnike analize mreže da bismo dobili celokupnu sliku društvene strukture kolonije. U redu? Ovako izgleda ova slika. U ovoj mreži, svi krugovi su čvorovi, pojedinačni slepi miševi, a linije između njih su društvene veze, povezanost između jedinki. Ispostavlja se da je ovo vrlo interesantna slika. Ova kolonija slepih miševa je podeljena na dve različite zajednice koje ne mogu da se predvide iz dnevne dinamike fizije i fuzije. Zovemo ih kodirane društvene jedinice. Što je još interesantnije, svake godine, oko oktobra, kolonija se raziđe, i svi slepi miševi hiberniraju odvojeno, ali godinu za godinom kada se u proleće ponovo okupe zajednice ostaju iste.
So these bats remember their friends for a really long time. With a brain the size of a peanut, they maintain individualized, long-term social bonds, We didn't know that was possible. We knew that primates and elephants and dolphins could do that, but compared to bats, they have huge brains. So how could it be that the bats maintain this complex, stable social structure with such limited cognitive abilities?
Ovi slepi miševi pamte svoje prijatelje veoma dugo. Sa mozgom veličine kikirikija, oni čuvaju samostalne, dugoročne društvene veze. Nismo znali da je to moguće. Znali smo da primati i slonovi, i delfini mogu to da rade, ali u poređenju sa slepim miševima imaju ogromne mozgove. Pa kako je moguće da slepi miševi održavaju kompleksne, stabilne društvene strukture uz tako ograničene kognitivne sposobnosti?
And this is where complexity brings an answer. To understand this system, we built a computer model of roosting, based on simple, individual rules, and simulated thousands and thousands of days in the virtual bat colony. It's a mathematical model, but it's not complicated. What the model told us is that, in a nutshell, each bat knows a few other colony members as her friends, and is just slightly more likely to roost in a box with them. Simple, individual rules. This is all it takes to explain the social complexity of these bats.
I upravo ovde nam kompleksnost daje odgovor. Da bismo razumeli ovaj sistem, napravili smo kompjuterski model gnežđenja, zasnovan na jednostavnim, pojedinačnim pravilima i simuliranim hiljadama dana u virtuelnoj koloniji slepih miševa. To je matematički model, ali nije komplikovan. Model nam je pokazao da, ukratko, svaki slepi miš zna nekoliko pripadnika druge kolonije kao svoje prijatelje i verovatnije je da će se sa njima gnezditi u kutiji. Jednostavna, pojedinačna pravila. Ovo je sve što je potrebno da bi se objasnila društvena kompleksnost ovih slepih miševa.
But it gets better. Between 2010 and 2011, the colony lost more than two thirds of its members, probably due to the very cold winter. The next spring, it didn't form two communities like every year, which may have led the whole colony to die because it had become too small. Instead, it formed a single, cohesive social unit, which allowed the colony to survive that season and thrive again in the next two years. What we know is that the bats are not aware that their colony is doing this. All they do is follow simple association rules, and from this simplicity emerges social complexity which allows the colony to be resilient against dramatic changes in the population structure. And I find this incredible.
Ali postaje bolje. Između 2010. i 2011, kolonija je izgubila više od dve trećine svojih članova, verovatno zbog veoma hladne zime. Naredne godine, nisu oformili dve zajednice, kao svake godine, što bi možda dovelo do izumiranja cele kolonije jer je bila previše mala. Umesto toga, oformili su jednu kohezivnu duštvenu grupu koja je omogućila koloniji da preživi tu sezonu i da napreduje sledeće dve godine. Znamo da slepi miševi nisu svesni da kolonija ovo radi. Oni samo prate jednostavna pravila povezivanja, i iz ove jednostavnosti proizilazi društvena kompleksnost koja omogućava koloniji da bude otpornija na dramatične promene u promeni populacije. I meni je ovo neverovatno.
Now I want to tell you another story, but for this we have to travel from Europe to the Kalahari Desert in South Africa. This is where meerkats live. I'm sure you know meerkats. They're fascinating creatures. They live in groups with a very strict social hierarchy. There is one dominant pair, and many subordinates, some acting as sentinels, some acting as babysitters, some teaching pups, and so on. What we do is put very small GPS collars on these animals to study how they move together, and what this has to do with their social structure. And there's a very interesting example of collective movement in meerkats. In the middle of the reserve which they live in lies a road. On this road there are cars, so it's dangerous. But the meerkats have to cross it to get from one feeding place to another. So we asked, how exactly do they do this? We found that the dominant female is mostly the one who leads the group to the road, but when it comes to crossing it, crossing the road, she gives way to the subordinates, a manner of saying, "Go ahead, tell me if it's safe." What I didn't know, in fact, was what rules in their behavior the meerkats follow for this change at the edge of the group to happen and if simple rules were sufficient to explain it.
Sada želim da vam ispričam još jednu priču, ali moramo da putujemo iz Evrope u pustinju Kalahari u Južnoj Africi. Ovde žive merkati. Siguran sam da znate šta su merkati. Oni su fascinantna bića. Žive u grupama sa vrlo striktnom društvenom hijerarhijom. Postoji jedan dominantan par, i mnogo podređenih, neki su stražari, neki su dadilje, drugi podučavaju mlade, i tako dalje. Mi smo stavili vrlo male GPS ogrlice ovim životinjama da bismo proučavali kako se kreću zajedno, i kakve ovo ima veze sa njihovom društvenom strukturom. I postoji vrlo interesantan primer kolektivnog kretanja merkata. Na sredini rezervata u kome žive postoji put. Na ovom putu ima automobila, znači opasno je. Ali merkati moraju da ga pređu da bi prešli s jednog mesta hranjenja na drugo. Pa smo se zapitali, kako tačno oni to postižu? Otkrili smo da je dominantna ženka uglavnom ta koja predvodi grupu do puta, ali što se tiče prelaženja puta, daje prednost podređenima, kao da im govori: "Ajde idi, kaži mi da li je bezbedno." Ono što nisam znao, je zapravo koja pravila ponašanja merkati slede prilikom ove promene na ivici grupe i da li su jednostavna pravila dovoljna da to objasne.
So I built a model, a model of simulated meerkats crossing a simulated road. It's a simplistic model. Moving meerkats are like random particles whose unique rule is one of alignment. They simply move together. When these particles get to the road, they sense some kind of obstacle, and they bounce against it. The only difference between the dominant female, here in red, and the other individuals, is that for her, the height of the obstacle, which is in fact the risk perceived from the road, is just slightly higher, and this tiny difference in the individual's rule of movement is sufficient to explain what we observe, that the dominant female leads her group to the road and then gives way to the others for them to cross first. George Box, who was an English statistician, once wrote, "All models are false, but some models are useful." And in fact, this model is obviously false, because in reality, meerkats are anything but random particles. But it's also useful, because it tells us that extreme simplicity in movement rules at the individual level can result in a great deal of complexity at the level of the group. So again, that's simplifying complexity.
Tako sam napravio model, model simuliranih merkata koji prelaze simulirani put. To je pojednostavljen model. Merkati koji se kreću su kao nasumične čestice čije je jedinstveno pravilo da se poravnaju. Oni se jednostavno kreću zajedno. Kad ove čestice dođu do puta, one osete neku vrstu prepreke, i odbiju se o nju. Jedina razlika između dominantne ženke, ovde prikazane crveno, i ostalih jedinki, je ta što je za nju visina prepreke, što je zapravo rizik koji predstavlja put, neznatno veća, i ova mala razlika u indvidiualnom pravilu kretanja je dovoljna da se objasni ono što vidimo, da dominantna ženka vodi njenu grupu do puta, a onda daje prednost drugima kako bi oni prešli prvi. Džordž Boks, engleski statističar, jednom je napisao: "Svi modeli su lažni, ali neki su korisni." I zapravo, ovaj model je očigledno lažan, jer u stvarnosti, merkati su sve osim nasumičnih čestica. Ali je takođe koristan, jer nam otkriva da ekstremna jednostavnost u pravilima kretanja na nivou jedinke može rezultirati velikom kompleksnošću na nivou grupe. Ponovo, to je uprošćavanje kompleksnosti.
I would like to conclude on what this means for the whole species. When the dominant female gives way to a subordinate, it's not out of courtesy. In fact, the dominant female is extremely important for the cohesion of the group. If she dies on the road, the whole group is at risk. So this behavior of risk avoidance is a very old evolutionary response. These meerkats are replicating an evolved tactic that is thousands of generations old, and they're adapting it to a modern risk, in this case a road built by humans. They adapt very simple rules, and the resulting complex behavior allows them to resist human encroachment into their natural habitat.
Želeo bih da dam zaključak o tome zašto je ovo važno za celu vrstu. Kad dominantna ženka da prednost podređenom to nije iz pristojnosti. Zapravo, dominantna ženka je ekstremno važna za koheziju grupe. Ako ona umre na putu cela grupa je izložena riziku. Ovo ponašanje izbegavanja rizika je vrlo star evolutivni odgovor. Ovi merkati oponašaju naprednu taktiku koja je stara hiljadama generacija, i prilagođavaju je savremenim rizicima, u ovom slučaju putu koji su izgradili ljudi. Prilagođavaju vrlo jednostavna pravila, i rezultirajuće kompleksno ponašanje im omogućava da se odupru ljudskom prodiranju u njihovo prirodno stanište.
In the end, it may be bats which change their social structure in response to a population crash, or it may be meerkats who show a novel adaptation to a human road, or it may be another species. My message here -- and it's not a complicated one, but a simple one of wonder and hope -- my message here is that animals show extraordinary social complexity, and this allows them to adapt and respond to changes in their environment. In three words, in the animal kingdom, simplicity leads to complexity which leads to resilience.
Na kraju, to mogu biti slepi miševi koji menjaju društvenu strukturu kao odgovor na smanjenje populacije, ili merkati, koji pokazuju neviđene adaptacije na ljudski put, ili to može biti druga vrsta. Moja poruka ovde, i nije komplikovana, već jednostavna, puna čuđenja i nadanja. Moja poruka je da životinje pokazuju neverovatnu društvenu kompleksnost i to im omogućava da se prilagode i odgovore na promene u njihovom okruženju. U tri reči, u životinjskom carstvu, jednostavnost vodi kompleksnosti što vodi do otpornosti.
Thank you.
Hvala.
(Applause) Dania Gerhardt: Thank you very much, Nicolas, for this great start. Little bit nervous? Nicolas Perony: I'm okay, thanks. DG: Okay, great. I'm sure a lot of people in the audience somehow tried to make associations between the animals you were talking about -- the bats, meerkats -- and humans. You brought some examples: The females are the social ones, the females are the dominant ones, I'm not sure who thinks how. But is it okay to do these associations? Are there stereotypes you can confirm in this regard that can be valid across all species? NP: Well, I would say there are also counter-examples to these stereotypes. For examples, in sea horses or in koalas, in fact, it is the males who take care of the young always. And the lesson is that it's often difficult, and sometimes even a bit dangerous, to draw parallels between humans and animals. So that's it. DG: Okay. Thank you very much for this great start. Thank you, Nicolas Perony.
(Aplauz) Dania Gerhard: Nikolase, mnogo ti hvala na ovom sjajnom početku. Malo si nervozan? Nikola Peroni: Dobro sam, hvala. DG: Super. Sigurna sam da su mnogi ljudi iz publike pokušali da pronađu vezu između životinja koje si pominjao - slepih miševa, merkata - i ljudi. Izneo si neke primere: ženke su društvene, ženke su dominantne, nisam sigurna ko kako razmišlja. Da li je u redu praviti te asocijacije? Da li ovde postoje stereotipi koji važe za sve vrste? NP: Pa, rekao bih da postoje i suprotni primeri ovim stereotipima. Na primer, kod morskih konja i koala, mužjaci su zapravo ti koji uvek brinu o mladuncima. Naravoučenije je, da je često teško, a ponekad i pomalo opasno, povlačiti paralele između ljudi i životinja. To je to. DG: U redu. Mnogo ti hvala za ovaj sjajan početak. Hvala, Nikola Peroni.