Exploring The Superorganism
November 5, 2008
Bert Hölldobler lecture presented as part of the Darwin Distinguished Lecture Series at the Phoenix Botanical Gardens. These events are sponsored by Arizona State University, Office of the President, College of Liberal Arts and Sciences, School of Life Sciences, and the Center for Biology and Society.
Transcript
Quentin Wheeler – Vice President and Dean of the College of Liberal Arts and Sciences: [0:01] It ’s a great pleasure and honor to introduce to you Professor Bert Hoelldobler. [0:05] [applause]
Dr. Biology: [0:14] Well, thank you very much, Quentin. And good evening, ladies and gentlemen. It is really a great pleasure that... I think it was our president, Michael Crow, who had the idea that this book launch should take place here at ASU. And when I called my friend - co-author - Ed Wilson, whether he would be willing to come, he said, "Of course I ’ll come!" And here he is! [0:41] And yesterday, he gave a splendid opening of our distinguished lecture series in memory of Darwin. And I have the honor to introduce today our book, and I will explore with you the super-organism. Before I do this, however, I want also to thank Rob Page and his outstanding team for organizing this event. It ’s just marvelous how smoothly everything works. Thank you very much.
[1:14] Now ladies and gentlemen, what is a super-organism? The simplest definition: it ’s a group of individuals in which the members are so tightly organized and tightly united that they develop traits characteristic of an ordinary organism. It ’s a very simple definition, but this is basically what a super-organism is.
[1:46] Now we find such groups especially in the eusocial insects. Now what is a eusocial insect, or truly social insect? A truly social insect society is characterized, basically by a distinct division of labor between a reproductive individual or a few reproductive individuals, and many non-reproductive, sterile individuals, who raise the offspring of the reproductive individuals.
[2:23] They hunt and collect food. They defend and raise - as I already said - the offspring. They defend the colony, they defend the territories, they build the nests, and they do all the other tasks to keep the colony thriving and reproducing. And there is an overlap of generations.
[2:46] Now such eusocial insects - and the best-known example are the honeybees. This is a highly advanced eusocial system. As you see, there is also what we biologists call a morphological skew. The queen is about one quarter larger than the workers.
[3:13] All females are sterile workers. This highly advanced eusocial system, as I said before, is characterized by an incredibly sophisticated division of labor system.
[3:30] Now the division of labor and the organization of the division of labor is a highly complex trait, which sometime during evolution must have emerged as a true novelty. And it emerged as a change in the ontogenetic development or program of a normal insect organism.
[4:03] Now in order to study this change, you can take an experimental approach, for example, by analyzing the genetic, physiological, and developmental mechanisms, which underlie the behavior of most insects, and combine these analyses with theoretical models about the social evolution.
[4:32] Once you do this combination, you get a new and actually very insightful view of the evolution of these social systems.
[4:44] Now this kind of work is best done on the honeybees - and especially here at ASU, in the research groups headed by Rob Page and Drew Hamilton. The honeybees are wonderful model systems to study these physiological traits which lead to a division of labor system, in a highly advanced eusocial system.
[5:10] However, if you want to understand the trajectories from primitive eusocial systems ’ evolutional pathway to this highly evolved eusocial system like in the honeybees; you ’ll find better examples - research examples - in the ants. This is an example where you see a highly advanced eusocial system: the beginning of a colony with a gigantic queen, in comparison to the sterile individuals, or workers.
[5:46] This is a reproductive unit of the super-organism, this queen. And this is the somatic units, which really make the super-organism. And their work actually ensures the tremendous reproduction of this one queen. Now this society will grow to hundreds of thousands of individuals, and sometimes millions. And you get these large colonies, which are unbelievably successful in their ecological settings.
[6:26] The question is, of course: why are they so successful in comparison to any solitary insect? And one such insect colony can do many things and can be in many places at the same time, because they deploy their worker force.
[6:47] They do this because they have this fantastic division of labor system. Now because of this division of labor, they occupy broad, very productive ecological niches, and outcompete all solitary insects.
[7:07] I ’ll give you just one number which illustrates the tremendous success of these highly advanced eusocial systems, like this Formica species here - this mound-building Formica species. There are hundreds of thousands of individuals and only a few queens.
[7:27] The ants, in their totality, make up only about two percent of all known animal species on our planet, but they comprise thirty percent of the entire animal biomass, and seventy to eighty percent of the entire insect biomass.
[7:49] And if you take the dry weight of all ants living on this earth, they come in order of magnitude close to the dry weight of all humans on this planet. These numbers just illustrate the tremendous success they have. Now when you zoom in... And as I said, the division of labor is the key.
[8:12] Because of the division of labor, they became so successful. And the division of labor has developed to such a degree in this highly advanced eusocial system that we can correctly call them a super-organism. Now, we ’ll come back to this.
[8:31] Of course, division of labor can only work by means of communication. In fact, no division of labor can work without communication - even the division of labor within a cell. The organelle in the cell - cooperate by communication. This is what cell biologists do.
[8:55] The cooperation of cells in an organism and the organs in an organism cooperate by communication. In the brain, the neurons cooperate by communication. Those who study super organisms, of course, study the communication of individuals within this super organism.
[9:18] Studying communication is the key of understanding the social behavior of any animal group and, especially, of the super organism. If you want to understand the internal workings of the super organisms, we have to study communication. We can talk a whole hour - even longer - about communication. But I want to give you one example.
[9:40] Because the ants work as a super organism, they can actually prey on pretty large prey objects. Although the ants are tiny, they can subdue large objects. And, because they do it in cooperation, they can actually prey on other super organisms.
[9:59] This ant, which is an illustration, the pomerant ant preys on termites. They send out scouts to explore new termite galleries. Once they have found one, they run home and recruit an army of nest mates of hundreds - 100, 200 or 300 - of workers.
[10:19] They do it by a multi-modal communication system. Communication in ants is very complex. When they come into the nest, they show this modal display of shaking behavior. Others show a knocking behavior or striolation behavior.
[10:34] These are modulatory signals. This means that they sort of... They are attention signals, more or less. They say, "Attention." The other nest mates now pay attention. Their threshold to respond to other signals is now lowered.
[10:51] Then, they discharge a chemical signal, the chemical trail. As you see, the ant bends the abdomen forward and drags this part over the ground.
[11:00] Let ’s take a very close look here at this part. It is the enlarged picture which shows a big gland, with mainly glandular cells. Each gland is drained by a duct here. They penetrate here. They intersect in the membrane. This is the sixth terichai. This is the seventh.
[11:19] There is a cup structure, as you see. This secretion is stored in this cup structure. Here, you see coagulated secretion. Most likely what is produced here is a trail pheromone. This is a signal which tells the nest mates to follow this chemical trail to the target area.
[11:39] Now, we have to test this. Here is this gland that I just said. Here is the cup structure. But the ant bends the abdomen forward so that he can now drag this part over the ground.
[11:51] What we do is we dissect out this gland in a little micro-operation. We take this gland out, the poison gland, as a control. We did this because colleagues of ours published a paper saying that they lay trail with the poison gland.
[12:09] What we now do is we have the nest. The ants are all in the nest in the laboratory. In front of the nest, we have a piece of paper and we draw two pencil lines for our own orientation. Then we have a micro-syringe. And along one line, we draw the secretion of the poison gland. The other one is the secretion of the pichachu gland - this one.
[12:32] Then we open the door. This is what happens. They follow beautiful the pichachu gland. None follow the poison gland. I always say that I don ’t need a statistical test to prove. But it is the pichachu gland.
[12:48] Here, you saw ants communicate mainly by chemical means, but not alone. Modal displays and all sorts of other mechanical sequences are more important than we acknowledged in the past. Now, this is one of the interesting new developments.
[13:06] Let me talk at length about this. Don ’t worry. I wanted to show you that ants are a wonderful canvas. These are all different structures of trail pheromones. Many of them identified in our own laboratory in cooperation with the national project CANVAS.
[13:25] I gave you a brief glance, first, to a fully-developed ultimate super organism. However, when we really look at the ant world, we find that there are many primitive social species, where you don ’t have these well functioning, highly cooperative systems.
[13:47] One example that I want to show you is a species which lives in India, Southeast Asia and in the laboratory of Jürgen Liebig at ASU. It is the ’Harpegnathos ’. The dots are made by Jürgen. So they are not coming with these beautiful dots.
[14:09] As you recognize, you don ’t have any morphological skew. They all have the same size. When you look inside, they are as endowed as any others to reproduce. They can mate, they have sperm. In fact, when we dissected colonies, we were amazed. Sometimes 80 percent are mated.
[14:33] How do they regulate reproduction? How is the division of labor coming about? Each one should be interested in reproduction. Indeed, when you watch them carefully, as Jürgen did, they have aggressive interactions within the colony, regionalist fighting.
[14:52] Jürgen demonstrated the indicators of reproductive states by hydrocarbon patterns and by chemical uniform. He recognized this, such a regionalized fate is that the thrash each other with their antennae, often deeply.
[15:09] Then it can escalate to a real wrestling fight. Mind you, it is always in the colony. So, real friction...
[15:16] I want to show this briefly in a movie which I got from Jürgen Liebig. Here is his regionalized fighting, back and forth, thrashing. And, then, attack! This is the ultimate of dominance into action.
[15:34] This one ant wanted to become fertile, you know? The dominant one does not allow it. So they police it. Finally, this is the status.
[15:47] OK. So, the winner lays the eggs, here. Do you see the eggs? It pulls the egg out. She may be active for a while. And then she wanes in her fertility. A revolution takes places within this society. Again, we have friction and fighting.
[16:08] When we now look at such a society... In this picture, each circle here is one of these societies, OK? As you saw, there is a lot of friction going on within, competition within the society - fighting.
[16:25] The question is: How much is competition going on between societies? You can see with their forage, their individual forages, they occasionally encounter each other. But they avoid each other. There is no territoriality, no defense of the nest, nothing.
[16:40] The main fighting is within the society. So there is, literally, almost no competition between societies. And Ed and I take, in this book, a multi-level selection approach. In this case, the selection within the society, the individual selection and, yes, at the kin level, selection is going on within the society. Between colony selection, is least driven by inter - between colony - competition. It literally does not exist.
[17:18] Now, in this case, within-colony selection is stronger than between-colony selection. However, of course, ecological forces favor cooperation. Which is, of course, then often a kind of between-colony selection.
[17:39] But the main force between colony competition is not existence. Now we make a big step to a true superorganism. I, for example, would not call yet such a primitive view social system a true superorganism. It depends where you draw the line. I say there is too much friction within the colony.
[18:01] Now I come to a true superorganism: the leaf weaver ants. The weaver ants are known because they build these wonderful leaf tent nests, and this, probably, is the most wonderful example of cooperation in the animal world.
[18:16] In order to build these nests, they build living chains. One ant hooks onto the other, and then they manipulate the leaf edges. And if one chain is not strong enough, they build more chains, and they heave up the leaf.
[18:32] And when they reach a certain position, a crew holds the leaf and another group runs into the already existing nest, and they bring out the last installed larvae, which normally in this ant group - I mean, in this family - spin the cocoon, the pupate. But they are used as living spinning or weaving shuttles. They are motionless.
[18:58] And actually Ed and I, we did a study in - I think it was in the 70s - where we studied the communication between the weaver/worker and the larva.
[19:13] The larva has a very stiff position and waits for a tactile signal on the cheeks with the antennae, and then releases from the labial gland the silk. And then the larva is moved back and forth, back and forth, back and forth. And in this way, these wonderful nests are created.
[19:33] Now, I should say one colony lives in about two hundred, three hundred such tent nests. They are huge nests, huge nest areas. When you open them, most are filled with brood, but only one day the gigantic queen - here you see the head of the queen, the thorax - and she is covered by workers. Large workers here - the majors - and the smaller workers are minors.
[20:01] The minors usually take care of the brood, and you hardly see them outside. If the minors are needed in another nest, they are just picked up by the large ones and carried to the place where they are needed. Now, these are the ones you deal with when you work with them in the field. Highly aggressive - this ant sees me, faces me, attacks if I come close enough. And they are highly territorial, the most territorial ant.
[20:34] This is work we did together, Ed and I, in the 70s - actually, at the peak of the sociobiology controversy -- ’75, ’76, ’77, we did this work, ’78. And as soon as a foreign ant from a neighboring colony ranges too far, it ’s immediately attacked - recognized again based on a hyrdrocarbon uniform. And then some other ants move home.
[21:01] And I wanted just to show you again the communication. This is how they normally move. So they now move home, up to the nests, and bend down the gaster, and a gland is extruded here, which you see here. Here, you see the photograph. Actually, you might even see the glandular applicator here, this white dot.
[21:20] And they lay a trail. But the ants don ’t respond alone to the trail pheromone. This made us - actually, we were desperate. We did all these tests and they didn ’t respond as they should, but we knew this is the gland.
[21:33] Well, it turned out whenever they encounter a nest mate, the worker laying a trail stops laying a trail, goes briefly through an aggressive display - open mandibles, raising the abdomen, jumping back and forth in a split second - and then move on.
[21:51] What does she do? It ’s an icon. She demonstrates aggressive behavior actually, which derived in evolution. This is a behavior here, the jerking. Now I show you how an ant behaves before they go in a real fight, if there is a real... We behavioral biologists call this "intention movement." This is it. This is what they do before they go in a real fight.
[22:19] So like a dog baring the teeth, they go through this display before they go into the clinch. So what happened is during the evolution of this aggressive display signal, which is a phenomenon we call ritualization, an intention movement this building block of the intention movement was used and be then formed in a second function to become a signal saying, "Move down this trail. There is an invasion."
[22:51] They use other motor displays. They use the same gland when they recruit new food sources, but they use a different motor display. You might say it ’s a primitive syntax, almost.
[23:05] The ants responded, approached by these, show a brief aggressive "yes" signal. Somebody once said to me, they have perhaps mirrors respond like this, and then move down, and when they reach the invasion site, hell breaks out - real fighting.
[23:25] So these ants have huge territories. Just look at the scale. This is one colony. Each dot is a major tree in the Shimba Hills in Kenya, where I did the fieldwork. And occupied in each tree, many, many of these tent nests, and they ’re all interconnected. There ’s one colony and only one queen, one reproductive unit, and hundreds of thousands of workers occupying this.
[23:53] This is another colony - another one, another one, and so on. In between, you have these corridors, which I love to call "no ant ’s land."
[24:02] [laughter]
Bert: [24:03] What you now have - and Ed and I, we always had this conversation, and I think this was the first discovery, actually for insects. They have a truly colony-specific territorial pheromone. Now, let ’s look again at these. [24:19] Each circle is again a colony, and these are the individuals - I just have four in there. As you saw, there is tremendous territoriality and competition between the colonies. When you look inside, there is literally no competition among the workers within. Zero.
[24:40] So now we have a situation where the main selective force which shapes this superorganism is between-colony selection. The stronger the between-colony competition, the stronger the favoring of cooperation within the colony, and making the division of labor more and more efficient, and shaping it.
[25:10] So the shaping of division of labor, communication systems, and adaptive tomographies of castes is all achieved by between-colony selection. And I give you now one example where this can be beautifully demonstrated: the leaf cutter ants.
[25:28] The leaf cutter ants - and we write about this in the book, quite extensively. The leaf cutter ants are the major herbivores in the neotropics. They cut leaf fragments, as you see here, and carry these fragments along huge trails - two hundred, three hundred meters long trails - to their gigantic nests.
[25:52] Here is this trunk root, this very permanent trunk root entering the nest entrance, and they carry these leaf fragments deep down into the nest chambers. And there they culture a fungus, and they live from this fungus.
[26:10] So there ’s a kind of symbiosis equivalent to agriculture. It evolved in these leaf cutter ants about eight to twelve million years ago, but this symbiosis between ants and fungus is much older, roughly 50 million years.
[26:31] The harvesting, processing, of this leaf material and the culturing of the fungus, and this is one of the beautiful studies of Ed Wilson, is based on this diversity of sub-castes of workers. You have the gigantic workers. You have the mini workers. These leaf cutter ends are known for beautiful diversity of sub-castes.
[26:57] Now, I have to say to the molecular biologists, this little ant will not grow to become a big one. Once they are enclosed from a pupa, they have reached the size they will always be. They have the same age, same genetic makeup. There ’s another interesting question of how these castes come about and are getting the work done in our laboratories at ASU.
[27:30] Now Ed demonstrated in the ’80s that the whole processing of the leaves and culturing of the fungus is organized like along an assembly line. The big ones, the strong ones, cut the heavy material, as you see here. Then the next size carries the leaves in. Then the next group processes the leaves. And finally the smallest ones take care of what ’s a fungus.
[28:03] It ’s a beautiful sequence. You can see how these different sub-castes are really designed, tailored, to fulfill, in an almost optimal way, the particular task spectrums they are made for.
[28:19] Now, there ’s only one individual, a gigantic reproductive unit, the queen. This queen mates in her life only once after she leaves the mother nest. She mates with five, six males, and then she lives for 10 to 20 years.
[28:40] The males, after mating, die, but as an ant male, forgive me for saying this in this somewhat sloppy way, but as an ant male, you have only once fun in your life and then you die, but you can become a father 20 years after you died.
[29:00] Because the ants developed a sperm bank, what we call a sperm pocket, inside the body of the queen, where the queen stores between 200 and 300 million sperms. And she produces, in her lifetime, between 150 to 250 million offspring. Many of them are workers, but nevertheless, about 50 million are reproductive.
[29:34] So, you see, this is the ultimate superorganism. You have a reproductive unit. No solitary insect has ever been found which can be so productive. This queen lives so long.
[29:51] You have this reproductive unit and this incredibly well-designed, many, many sterile females, which often leave home with their ovaries, and do better and better and better with evolution, for what they are designed. And this is clearly an example, and I cannot see how it can be differently explained then by between colony level selections.
[30:19] Now these nests are gigantic, you see it here, with ventilation tubes, air conditioning, chimneys. You have to remember this fungus produces a lot of CO2, carbon dioxide, so they have to regulate the air flow.
[30:37] We want to understand how these nests are inside. Many people try to dig them out, so however then my good friend and former colleague and member of my research group at the University of Vicksburg, Flavia Rosas and his friend Jose, I forgot his name. It just escaped.
[31:03] They did something remarkable. They wanted to see the architecture inside, so what they did, they poured in 10, 000 liters of water mixed with six tons of cement. Then they waited for three weeks, and then they dug the whole nest out, and here it is. It is 40 square meters of area going eight meters deep down.
[31:34] Just look at this beautiful structure. All these football-like structures are fungus chambers, now of course, petrified. Here you see long channels, all these beautiful fungus chambers that you see. This could be a piece of art.
[31:56] Now, where ’s the architect? There is none. It ’s a typical example of a self-organized system. Self-organized system is so easily said, but it ’s a cascade of key stimuli which lead to these structures, which actually have even species-specific features.
[32:18] So, you have here an example of what Dawkins called an extended phenotype. This is an extended phenotype. Of course, it was again selected by colony-level selection or between-group selection.
[32:33] Now, at the end, we are back home, here in Arizona. Down in the Cherry Cola mount, this is Port La Peak, for those of you who know this beautiful area. These were my old hunting grounds. Now, unfortunately, this area is pretty much spoiled because it has been sold off, parceled, and unfortunately, ugly trailers now appear on this beautiful land.
[33:00] But it is an ant paradise. I did a lot of work there, but one ant which fascinated me the most were the honey ants. In order to survive in the desert, you have to have a storage policy. You can either collect seeds, harvesting ants, or you have living storage containers like these honey ants.
[33:24] So during the rain, monsoon rains, the ants bring in all sorts of liquid food, which may have been leaned from termites, and pump them into these ants, nest mates, which do nothing else than hanging motionless from the ceiling of the nest chambers, are filled up.
[33:43] Here, this is the abdomen; the intersect membrane is stretched. This first part of the abdominal, we call the social stomach or crop, is really getting very large, and then during dry season, these ants regurgitate back food to the colony. They can easily survive during the dry season.
[34:05] This is an interesting story by itself, but I was more interested about their territorial behavior. We talked briefly about the communication which regulates division of labor within a society, but as you know, we call a highly advanced insect society a superorganism, and like organisms, they communicate within one another.
[34:31] We have now to look how superorganisms communicate with one another. For example, when they compete for space, how do they negotiate a territorial contract? And these ants show it in a remarkable way.
[34:48] Above ground, sometimes when you walk through the desert, you see ants walking on stilt legs, not moving much around, confronting each other, hundreds of ants displaying like this. And in a piecemeal way, piece by piece, over 25 years, we ’ve finally sort of began to understand the story.
[35:11] These are territorial tournaments. They don ’t fight by physical fighting. It is an ecological adaptation, because they defend spatial temporal territories, they don ’t defend absolute territories. Just the moment, were they to find something, they stop the opposing colony. But this is only part of the story.
[35:33] For example, if you have two nests and they want to stop this one that has ventured too far in this direction, they have a tournament here. They send their display ants - usually the big ants - and they stand around and display. And they [the other nest] send theirs. But, it might be that this one is too weak and cannot summon enough of the display ants. Then it can come to a raid.
[36:02] The victor colony moves into the nest, they kill the queen, and then they pillage the nest. They carry out the pupae. The pupae are stolen - it ’s labor force. They bring them to their own nest.
[36:17] These pupae enclose in the foreign nest - not knowing that they are now seeing the light of this world in a foreign colony - get imprinted on the foreign colony odor, and now the work that they would have done in their own nest, they do for a foreign queen. This is true slavery. This is exploitation of the labor force of a foreign colony.
[36:42] Not only that, they pull out the honey pots and drag them over. Those that survive are placed on their ceiling and function now as honey pots for a foreign colony. They have no choice. And those that do not survive will be eaten - this is full of great nourishment.
[37:02] OK. I want to show you, briefly - it ’s not a good movie - how such a raid takes place. This is from the old days when I had a 60mm movie, but... [laughs]
[37:13] This is just a sequence of a raid I filmed. Most of the time these tournaments really take place between temporary territorial portals. Or, they move directly over to the nest entrance and stop these ants from foraging by engaging them in tournament display. It ’s interference competition.
[37:41] So, what we found is that these ants seem to be able to assess their opponent ’s strength during these tournament displays. These are some of the sequences of what they do: they go high on still leg, perform, and encounter each other. If it ’s a nest mate, they briefly jerk and separate.
[38:02] If it ’s an opponent, they go through a lateral display - as you see here - and then they separate again. And this is done again and again and again. So, they go through a random sequence of encounters between nest mate, nest mate, nest mate, opponent, nest mate, opponent. They show us they can recognize this and we know they have a chemical uniform.
[38:24] So, we played around with a couple of algorithmic models. One was the head-counting model, which I developed with Charles Lumsden. We said, "OK. If they go through this and have a head counter, and can somehow store a certain number of encounters, they get an idea of the ratio of representation. Then they can decide if they should escalate or hold the status quo or if they should retreat and close the next entrance and avoid the raid."
[38:56] Well, in order to test this you have to make detailed film and we have thousands of meters of tapes and 60mm film looking at this tournamenting. And I want to show you - again, it ’s a bad sequence - of what this behavior looks like. Here you see the display - it ’s not good but it shows well enough. The most physical thing they do is kick each other with their forelegs.
[39:29] [audience laughter]
Bert: [39:37] A detailed analysis of this tape showed, however, it is not a collective gathering of information. These display ants, actually don ’t collect much information. It is a smaller group of ants which move through the tournaments and get the information. We call them reconnaissance ants. [40:00] So, let me come back to the superorganism concept. We can say, like a deer which has its antlers and shows off to competing deer with the size of the antlers, this superorganism of the honey ants has the display ants.
[40:18] They send them out and they stand around and display. And the superorganism has the sensory organs, which are the reconnaissance ants, and they move through and test who is stronger, and, depending on this, they run home and get reinforcement recruits or they escalate to a raid.
[40:41] This is something we are currently working on here at ASU. I should also say that we demonstrated that these pupae, which they catch, are really incorporated into the colonies.
[40:54] Together with Jürgen Gadau, here from ASU, we did some genetical work looking at the mitochondrial DNA and could prove that some of these ants are from foreign mothers. With Steve Pratt, from ASU, I am beginning to study the reconnaissance behaviors, so this work is still going on.
[41:18] No question, these tournaments are information centers where the ants gather information about their opponents, and according to this information, they then decide which strategy to pursue. And, with this last picture... I cannot help but show you what are called "nothing fights," in pidgin English.
[41:41] I once gave this talk on the tournamenting at Harvard in the Anthropology Department during a lunch meeting, and one of my colleagues came to me and said, "Bert, you have to look at the ’nothing fights ’ of the Marings!" He gave me the literature and I read it and I was struck. It is exactly the same thing that they do.
[42:04] If they have a feud, they assemble their men every morning on a tournament side. They bring all their weapons and they shout terrible insults at each other, but nothing happens. They ’re cowards.
[42:20] As long as they are roughly the same size, nothing will escalate. They go home in the evening and come out the next morning and do the same thing - like myrmex sisters. Myrmex sisters ’ last sometimes a whole week, every day!
[42:34] [audience laughter]
[42:36] Finally, the Marings get bored and stay home. However, if one company is not careful enough and doesn ’t bring enough of their men, it comes to a raid. And Kim Hill can tell us what they raid.
[42:51] Well, ladies and gentlemen, I don ’t claim that there is a direct evolutionary line from these "nothing fights" of the Marings to the myrmex sisters. But, we behavioral ecologists like to look for analogies - how evolution found similar solutions to the same problems, and for me, this is remarkable.
[43:16] And, by the way, we shouldn ’t really laugh - we still do this. Remember the cold war when we counted armies, warheads, tanks, and built up just to keep the same force - hopefully never to be used? This is basically exactly the same.
[43:35] Thank you very much!
[43:36] [audience applause]
Announcer: [43:40] This lecture is part of the Arizona State University "Darwin Distinguished Lecture" series, and is sponsored by the ASU Office of the President, the College of Liberal Arts and Sciences, the School of Life Sciences, the Center for Biology in Society, and is a production of Grass Roots Studio. [end of audio]
Transcription by CastingWords