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reciprocal altruism. A third theory is, males help only other closely related males. A study done by The
Department of Fisheries and Wildlife provided evidence that males used a tit-for-tat strategy. The Department of Fisheries and Wildlife tested many different nests by placing stuffed crows by nests, and then observing behavior of neighboring males. The behaviors they looked for included the number of calls, dives, and strikes. After analyzing the results, there was not significance evidence for kin selection; the presence of extra-pair offspring did not affect the probability of help in nest defense. However, males reduced the amount of defense given to neighbors when neighbor males reduced defense for their nests. This demonstrates a tit-for-tat strategy, where animals help those who previously helped them. This strategy is one type of reciprocal altruism.
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examples in the manuscript, which has led to confusion about what were appropriate examples of reciprocal altruism for the last 50 years. In their contribution to that symposium, Rothstein and
Pierotti (1988) addressed this issue and proposed new definitions concerning the topic of altruism, that clarified the issue created by Trivers and Hamilton. They proposed that Delayed Return Altruism was a superior concept and used the term pseudo-reciprocity in place of DRA. For some reason, the paper by Rothstein and Pierotti did not catch hold, but it remains one of the best examinations of the relationship between altruism and kin selection. Rothstein and Pierotti also explain why Trivers' examples of Reciprocal Altruism are actually examples of delayed return altruism.
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altruism, the benefit to the receiver would have to be larger than the cost to the donor. This seems to hold as these bats usually die if they do not find a blood meal two nights in a row. Also, the requirement that individuals who have behaved altruistically in the past are helped by others in the future is confirmed by the data. However, the consistency of the reciprocal behaviour, namely that a previously non-altruistic bat is refused help when it requires it, has not been demonstrated. Therefore, the bats do not seem to qualify yet as an unequivocal example of reciprocal altruism.
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nearby host fish observed "cheater" cleaners and subsequently avoided them. In these examples, true reciprocity is difficult to demonstrate since failure means the death of the cleaner. However, if
Randall's claim that hosts sometimes chase off possible dangers to the cleaner is correct, an experiment might be constructed in which reciprocity could be demonstrated. In actuality this is one of Trivers' examples of Delayed Return Altruism as discussed by Rothstein and Pierotti 1988.
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within group members, displaying alliances. This would demonstrate vervet monkey's grooming behavior as a part of kin selection since the activity is done between siblings in this study. Moreover, following the criteria by
Stephen, if the study is to be an example of reciprocal altruism, it must prove the mechanism for detecting cheaters.
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consequences and therefore evolution of reciprocal altruism would not be possible. However, it is pointed out that this "conditioning device" does not need to be conscious. Condition number six is required to avoid cooperation breakdown through forward induction—a possibility suggested by game theoretical models.
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It is not known how individuals pick partners as there has been little research on choice. Modeling indicates that altruism about partner choices is unlikely to evolve, as costs and benefits between multiple individuals are variable. Therefore, the time or frequency of reciprocal actions contributes
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Grooming in primates meets the conditions for reciprocal altruism according to some studies. One of the studies in vervet monkeys shows that among unrelated individuals, grooming induce higher chance of attending to each other's calls for aid. However, vervet monkeys also display grooming behaviors
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It has been shown that predators learn specific localities and specialize individually on prey types and hunting techniques. It is therefore disadvantageous for a bird to have a predator eat a conspecific, because the experienced predator may then be more likely to eat them. Alarming another bird by
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unconditionally in the first period and behave cooperatively (altruistically) as long as the other agent does as well. If chances of meeting another reciprocal altruist are high enough, or if the game is repeated for a long enough amount of time, this form of altruism can evolve within a population.
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This example meets some, but not all, of the criteria described in
Trivers's model. In the cleaner-host system the benefit to the cleaner is always immediate. However, the evolution of reciprocal altruism is contingent on opportunities for future rewards through repeated interactions. In one study,
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The cleaning by cleaners is essential for the host. In the absence of cleaners the hosts leave the locality or suffer from injuries inflicted by ectoparasites. There is difficulty and danger in finding a cleaner. Hosts leave their element to get cleaned. Others wait no longer than 30 seconds before
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Nevertheless, this presentation lacks important elements of reciprocity. It is very hard to detect and ostracize cheaters. There is no evidence that a bird refrains from giving calls when another bird is not reciprocating, nor evidence that individuals interact repeatedly. Given the aforementioned
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A key requirement for the establishment of reciprocal altruism is that the same two individuals must interact repeatedly, as otherwise the best strategy for the host would be to eat the cleaner as soon as cleaning was complete. This constraint imposes both a spatial and a temporal condition on the
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The first two conditions are necessary for altruism as such, while the third is distinguishing reciprocal altruism from simple mutualism and the fourth makes the interaction reciprocal. Condition number five is required as otherwise non-altruists may always exploit altruistic behaviour without any
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also display reciprocal altruism, as described by
Wilkinson. The bats feed each other by regurgitating blood. Since bats only feed on blood and will die after just 70 hours of not eating, this food sharing is a great benefit to the receiver and a great cost to the giver. To qualify for reciprocal
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males help defend neighbor's nests. There are many theories as to why males behave this way. One is that males only defend other nests which contain their extra-pair offspring. Extra-pair offspring are juveniles which may contain some of the male bird's DNA. Another is the tit-for-tat strategy of
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In 1987 Trivers told a symposium on reciprocity that he had originally submitted his article under the title "The
Evolution of Delayed Return Altruism", but reviewer W. D. Hamilton suggested that he change the title to "The Evolution of Reciprocal Altruism". Trivers changed the title, but not the
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Numerous species of bacteria engage in reciprocal altruistic behaviors with other species. Typically, this takes the form of bacteria providing essential nutrients for another species, while the other species provides an environment for the bacteria to live in. Reciprocal altruism is exhibited
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The host fish allows the cleaner fish free entrance and exit and does not eat the cleaner, even after the cleaning is done. The host signals the cleaner it is about to depart the cleaner's locality, even when the cleaner is not in its body. The host sometimes chases off possible dangers to the
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In comparison to that of other animals, the human altruistic system is a sensitive and unstable one. Therefore, the tendency to give, to cheat, and the response to other's acts of giving and cheating must be regulated by a complex psychology in each individual, social structures, and cultural
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Another explanation for warning calls is that these are not warning calls at all: A bird, once it has detected a bird of prey, calls to signal to the bird of prey that it was detected, and that there is no use trying to attack the calling bird. Two facts support this hypothesis:
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Some animals seem to be unable to develop reciprocal altruism. For example, pigeons defect instead of a random response or a tit-for-tat in a
Prisoner's dilemma game against a computer. This may be due to favoring short-term thinking over long-term thinking.
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cleaner and on its host. Both individuals must remain in the same physical location, and both must have a long enough lifespan, to enable multiple interactions. There is reliable evidence that individual cleaners and hosts do indeed interact repeatedly.
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giving a warning call tends to prevent predators from specializing on the caller's species and locality. In this way, birds in areas in which warning calls are given will be at a selective advantage relative to birds in areas free from warning calls.
99:, although there still seems a slight distinction in that "tit for tat" cooperates in the first period and from thereon always replicates an opponent's previous action, whereas "reciprocal altruists" stop cooperation in the first instance of non-
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by an opponent and stay non-cooperative from thereon. This distinction leads to the fact that in contrast to reciprocal altruism, tit for tat may be able to restore cooperation under certain conditions despite cooperation having broken down.
329:. These flies consume nutrient-producing bacteria found on the leaves of plants; in exchange, they reside within the flies' digestive system. This reciprocal altruistic behavior has been exploited by techniques designed to eliminate
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is a behaviour whereby an organism acts in a manner that temporarily reduces its fitness while increasing another organism's fitness, with the expectation that the other organism will act in a similar manner at a later time.
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protect their offspring extremely aggressively by very quick drop-downs from a stationary flight over their enemies. Other birds often benefit from this behavior by breeding very close to the Arctic terns.
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Moralistic aggression. A protection mechanism from cheaters acts to regulate the advantage of cheaters in selection against altruists. The moralistic altruist may want to educate or even punish a cheater.
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characteristics of bird calling, a continuous bird emigration and immigration environment (true of many avian species) is most likely to be partial to cheaters, since selection against the
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of the cleaner and the host during actual cleaning, which cannot be interpreted as altruism, the host displays additional behaviour that meets the criteria for delayed return altruism:
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Gratitude and sympathy. A fine regulation of altruism can be associated with gratitude and sympathy in terms of cost/benefit and the level in which the beneficiary will reciprocate.
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Warning calls, although exposing a bird and putting it in danger, are frequently given by birds. An explanation in terms of altruistic behaviors given by
Trivers:
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The following examples could be understood as altruism. However, showing reciprocal altruism in an unambiguous way requires more evidence as will be shown later.
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between nitrogen-fixing bacteria and plants in which they reside. Additionally, it can be observed between bacteria and some species of flies such as
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Rothstein, S. I. (1988). "Distinctions among reciprocal altruism and kin selection, and a model for the initial evolution of helping behavior".
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and their hosts, though cleaners include shrimps and birds, and clients include fish, turtles, octopuses and mammals. Aside from the apparent
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Subtle cheating. A stable evolutionary equilibrium could include a low percentage of mimics in controversial support of adaptive sociopathy.
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Guilt and reparative altruism. Prevents the cheater from cheating again. The cheater shows regret to avoid paying too dearly for past acts.
802:
Eibi-Eibesfeldt, T (2010). "Ăśber
Symbiosen, Parasitismus und andere besondere zwischenartliche Beziehungen tropischer Meeresfische1".
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76:, who developed mathematical models for predicting the likelihood of an altruistic act to be performed on behalf of one's kin.
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Christopher Stephens shows a set of necessary and jointly sufficient conditions "... for an instance of reciprocal altruism:
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400:, the following emotional dispositions and their evolution can be understood in terms of regulation of altruism.
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2020:
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1331:
Seyfarth, Robert M; Cheney, Dorothy L (1984). "Grooming, alliances and reciprocal altruism in vervet monkeys".
1014:. Fauna of National Parks of the United States. Vol. Faunal Series No. 5. U.S. Government Printing Office.
482:
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1966:
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1140:"Cooperative Nest Defence in Red–winged Blackbirds: Reciprocal Altruism, Kinship or By–product Mutualism?"
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855:"A review of the Labrid fish genus Labriodes with descriptions of two new species and notes on ecology"
1284:"Food Sharing in Vampire Bats: Reciprocal Help Predicts Donations More than Relatedness or Harassment"
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2003:
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Calling birds are less attacked—predator birds attack calling birds less frequently than other birds.
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Bateman, MA (1967). "Adaptations to temperature in geographic races of the Queensland fruit fly
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traditions. Individuals differ in the degree of these tendencies and responses. According to
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Feder, H.M. (1966). "Cleaning symbioses in the marine environment". In Henry, S.M. (ed.).
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Lee, P.C. (1987). "Sibships: Cooperation and Competition Among Immature Vervet Monkeys".
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the performance of the behaviour must not depend on the receipt of an immediate benefit;
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There are two additional conditions necessary "...for reciprocal altruism to evolve:"
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conditions 1, 2, and 3 must apply to both individuals engaging in reciprocal helping.
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785:
756:
Grutter, Alexandra S. (2002). "Cleaning symbioses from the parasites' perspective".
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as instances of mutually altruistic acts. The concept is close to the strategy of "
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the behaviour must reduce a donor's fitness relative to a selfish alternative;
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The concept of "reciprocal altruism", as introduced by Trivers, suggests that
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922:
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1095:
Owen, D. F. (1963). "Similar polymorphismas in an insect and a land snail".
961:"Biting cleaner fish use altruism to deceive image-scoring client reef fish"
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Trust and suspicion. These are regulators for cheating and subtle cheating.
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more to an individual's choice of partner than the reciprocal act itself.
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the fitness of the recipient must be elevated relative to non-recipients;
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A large (indefinite) number of opportunities to exchange aid must exist.
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Wilkinson, G. (1988). "Reciprocal Altruism in Bats and Other Mammals".
1163:
1523:"Prisoner's Dilemma and the Pigeon: Control by Immediate Consequences"
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1946:
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Clarke, A.R.; Powell, K.S.; Weldon, C.W.; Taylor, P.W. (2010-11-02).
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236:, gives loud alarm calls from its tree perch when it sees a predator.
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1973:
1425:(Diptera: Tephritidae): what do we know to assist pest management?"
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69:
1138:
Olendorf, Robert; Getty, Thomas; Scribner, Kim (22 January 2004).
628:
Hamilton (1964). "The Genetical Evolution of Social Behavior II".
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The call frequencies match the hearing range of the predator bird.
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Green, Leonard; Price, Paul C.; Hamburger, Merle E. (July 1995).
397:
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Fauna of the National Parks of the United States: Fauna series
593:
Trivers, R.L. (1971). "The evolution of reciprocal altruism".
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1052:
Tinbergen, N. (1968). "On war and peace in animals and man".
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Putting this into the form of a strategy in a repeated
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Stephens, C. (1996). "Modelling Reciprocal Altruism".
681:(30th Anniversary ed.). Oxford University Press.
390:
1137:
1025:
Southern, H. N. (1954). "Tawny owls and their prey".
935:
755:
548:
1580:"A few misunderstandings about reciprocal altruism"
1520:
829:Heidiger, H. (1968). "Putzer-fische im aquarium".
797:
795:
917:. Vol. 1. Academic Press. pp. 327–380.
333:, which are fruit fly pests native to Australia.
3231:
1527:Journal of the Experimental Analysis of Behavior
891:Randall, J. E. (1962). "Fish service stations".
404:Friendship and emotions of liking and disliking.
206:The following evidence supports the hypothesis:
183:) in an apparent example of reciprocal altruism.
128:A mechanism for detecting 'cheaters' must exist.
801:
792:
1330:
936:Limbaugh, C.; Pederson, H.; Chase, F. (1961).
2933:
1638:
1193:
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723:British Journal for the Philosophy of Science
422:Partnerships. Altruism to create friendships.
1577:
1200:"Reciprocal Food Sharing in the Vampire Bat"
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2879:Transgenerational epigenetic inheritance
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39:The concept was initially developed by
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2642:Dialogues Concerning Natural Religion
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1007:
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187:An example of reciprocal altruism is
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346:
2993:Evolutionary models of food sharing
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463:Evolutionary models of food sharing
391:Regulation by emotional disposition
23:Diagram showing reciprocal altruism
16:Form of behaviour between organisms
13:
2047:Evolutionary developmental biology
1282:Carter, Gerald (January 2, 2013).
1039:10.1111/j.1474-919X.1954.tb02332.x
965:Proceedings of the Royal Society B
816:10.1111/j.1439-0310.1955.tb01523.x
273:
210:searching for cleaners elsewhere.
14:
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494:Mutual Aid: A Factor of Evolution
177:services a big eye squirrelfish (
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3199:
3188:
3187:
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2901:
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2891:
1471:from the original on 2018-11-04.
1444:10.1111/j.1744-7348.2010.00448.x
1288:Proceedings of the Royal Society
875:from the original on 2020-08-06.
350:
91:This is close to the notion of "
3127:Sociobiology: The New Synthesis
2704:Extended evolutionary synthesis
1893:Gene-centered view of evolution
1578:Schino, G.; Aureli, F. (2010).
1571:
1514:
1475:
1412:
1324:
1275:
1131:
804:Zeitschrift fĂĽr Tierpsychologie
516:Reciprocity (social psychology)
468:Gene-centered view of evolution
296:
147:
2832:Hologenome theory of evolution
2699:History of molecular evolution
1925:Evolutionarily stable strategy
1814:Last universal common ancestor
630:Journal of Theoretical Biology
621:
1:
2626:Renaissance and Enlightenment
1488:Australian Journal of Zoology
1074:10.1126/science.160.3835.1411
542:
381:
343:Reciprocal altruism in humans
2837:Missing heritability problem
2464:Gamete differentiation/sexes
1269:10.1016/0162-3095(88)90015-5
650:10.1016/0022-5193(64)90039-6
569:10.1016/0162-3095(88)90021-0
43:to explain the evolution of
7:
3218:Evolutionary biology portal
942:Bull. Mar. Sci. Gulf Caribb
938:"Shrimps that clean fishes"
595:Quarterly Review of Biology
483:Iterated prisoner's dilemma
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317:
308:
139:
10:
3271:
2469:Life cycles/nuclear phases
2021:Trivers–Willard hypothesis
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151:
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2354:
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2034:
1967:Parent–offspring conflict
1903:
1772:Earliest known life forms
1693:
1660:
1432:Annals of Applied Biology
1257:Ethology and Sociobiology
770:10.1017/S0031182002001488
557:Ethology and Sociobiology
458:Enlightened self-interest
336:
63:
2820:Cultural group selection
2684:The eclipse of Darwinism
2656:On the Origin of Species
2631:Transmutation of species
1484:Dacus (Strumenta) tryoni
3250:Evolutionary psychology
3013:Male warrior hypothesis
2983:Evolutionary psychology
2973:Dual inheritance theory
2825:Dual inheritance theory
2664:History of paleontology
853:Randall, J. E. (1958).
521:Reciprocity (evolution)
2513:Punctuated equilibrium
1834:Non-adaptive radiation
1782:Evolutionary arms race
1539:10.1901/jeab.1995.64-1
1300:10.1098/rspb.2012.2573
1198:Wilkinson, G. (1984).
1156:10.1098/rspb.2003.2586
1008:Murie, Adolph (1944).
977:10.1098/rspb.2002.2084
359:This section is empty.
286:
237:
222:Warning calls in birds
184:
175:advertising coloration
24:
2988:Evolution of morality
2805:Evolutionary medicine
2679:Mendelian inheritance
2387:Biological complexity
2375:Programmed cell death
2067:Phenotypic plasticity
1787:Evolutionary pressure
1777:Evidence of evolution
1675:Timeline of evolution
1596:10.4161/cib.3.6.12977
1144:Proc. R. Soc. Lond. B
735:10.1093/bjps/47.4.533
281:
240:Further information:
229:
161:
152:Further information:
22:
3240:Evolutionary biology
2968:Challenge hypothesis
2963:Behavioural genetics
2779:Teleology in biology
2674:Blending inheritance
2052:Genetic assimilation
1915:Artificial selection
1654:Evolutionary biology
1584:Commun. Integr. Biol
511:Psychological egoism
453:Competitive altruism
290:Red-winged blackbird
171:Labroides dimidiatus
29:evolutionary biology
3018:Reciprocal altruism
2842:Molecular evolution
2800:Ecological genetics
2669:Transitional fossil
2459:Sexual reproduction
2299:endomembrane system
2228:pollinator-mediated
2184:dolphins and whales
1962:Parental investment
1345:1984Natur.308..541S
1216:1984Natur.308..181W
1109:1963Natur.198..201O
1066:1968Sci...160.1411T
959:Bshary, R. (2002).
642:1964JThBi...7...17H
501:Norm of reciprocity
233:Garrulus glandarius
33:reciprocal altruism
3106:Sarah Blaffer Hrdy
3035:Sex and psychology
2815:Cultural evolution
1930:Fisher's principle
1859:Handicap principle
1849:Parallel evolution
1713:Adaptive radiation
1398:10.1007/bf02382182
1294:(1753): 20122573.
506:Prosocial behavior
438:Altruism (biology)
287:
238:
191:, such as between
189:cleaning symbiosis
185:
180:Priacanthus hamrur
165:: a small cleaner
163:Cleaning symbiosis
154:Cleaning symbiosis
81:prisoner's dilemma
25:
3227:
3226:
3151:Stephen Jay Gould
2915:
2914:
2531:Uniformitarianism
2484:Sex-determination
1989:Sexual dimorphism
1984:Natural selection
1888:Unit of selection
1854:Signalling theory
1500:10.1071/zo9671141
1423:Bactrocera tryoni
1210:(5955): 181–184.
1150:(1535): 177–182.
971:(1505): 2087–93.
526:Signalling theory
379:
378:
326:Bactrocera tryoni
242:Signalling theory
3262:
3215:
3203:
3202:
3191:
3190:
3172:Not in Our Genes
3161:Richard Lewontin
3023:Sexual selection
2942:
2935:
2928:
2919:
2918:
2905:
2895:
2894:
2694:Modern synthesis
2454:Multicellularity
2449:Mosaic evolution
2334:auditory ossicle
2016:Social selection
1999:Flowering plants
1994:Sexual selection
1647:
1640:
1633:
1624:
1623:
1618:
1617:
1607:
1575:
1569:
1568:
1558:
1518:
1512:
1511:
1479:
1473:
1472:
1470:
1455:
1429:
1421:"The ecology of
1416:
1410:
1409:
1379:
1373:
1372:
1353:10.1038/308541a0
1328:
1322:
1321:
1311:
1279:
1273:
1272:
1252:
1246:
1245:
1235:
1224:10.1038/308181a0
1195:
1186:
1185:
1175:
1135:
1129:
1128:
1117:10.1038/198201b0
1092:
1086:
1085:
1060:(3835): 1411–8.
1049:
1043:
1042:
1022:
1016:
1015:
1005:
999:
998:
988:
956:
950:
949:
933:
927:
926:
910:
901:
900:
888:
877:
876:
874:
859:
850:
839:
838:
831:Natur und Museum
826:
820:
819:
799:
790:
789:
753:
747:
746:
718:
693:
692:
679:The Selfish Gene
675:Dawkins, Richard
671:
662:
661:
625:
619:
618:
590:
573:
572:
552:
478:Helping behavior
374:
371:
361:You can help by
354:
347:
95:" introduced by
3270:
3269:
3265:
3264:
3263:
3261:
3260:
3259:
3230:
3229:
3228:
3223:
3179:
3139:
3096:Richard Dawkins
3074:
3065:Dunbar's number
3003:Kin recognition
2998:Group selection
2951:
2946:
2916:
2911:
2883:
2810:Group selection
2783:
2708:
2612:
2539:
2501:Tempo and modes
2495:
2350:
2254:
2071:
2030:
1906:
1899:
1876:Species complex
1689:
1680:History of life
1656:
1651:
1621:
1576:
1572:
1519:
1515:
1480:
1476:
1468:
1427:
1417:
1413:
1380:
1376:
1339:(5959): 541–3.
1329:
1325:
1280:
1276:
1263:(2–4): 85–100.
1253:
1249:
1196:
1189:
1136:
1132:
1103:(4876): 201–3.
1093:
1089:
1050:
1046:
1023:
1019:
1006:
1002:
957:
953:
934:
930:
911:
904:
889:
880:
872:
862:Pacific Science
857:
851:
842:
827:
823:
800:
793:
754:
750:
719:
696:
689:
672:
665:
626:
622:
591:
576:
553:
549:
545:
540:
448:The common good
433:
393:
384:
375:
369:
366:
345:
339:
320:
311:
299:
276:
274:Nest protecting
244:
224:
156:
150:
142:
97:Anatol Rapoport
66:
58:
17:
12:
11:
5:
3268:
3258:
3257:
3252:
3247:
3242:
3225:
3224:
3222:
3221:
3209:
3197:
3184:
3181:
3180:
3178:
3177:
3176:
3175:
3163:
3158:
3153:
3147:
3145:
3141:
3140:
3138:
3137:
3132:
3131:
3130:
3118:
3113:
3108:
3103:
3101:Daniel Dennett
3098:
3093:
3088:
3082:
3080:
3076:
3075:
3073:
3072:
3067:
3062:
3061:
3060:
3054:
3053:
3052:
3037:
3032:
3031:
3030:
3020:
3015:
3010:
3005:
3000:
2995:
2990:
2985:
2980:
2975:
2970:
2965:
2959:
2957:
2953:
2952:
2945:
2944:
2937:
2930:
2922:
2913:
2912:
2910:
2909:
2899:
2888:
2885:
2884:
2882:
2881:
2876:
2871:
2866:
2861:
2860:
2859:
2849:
2844:
2839:
2834:
2829:
2828:
2827:
2822:
2817:
2807:
2802:
2797:
2791:
2789:
2785:
2784:
2782:
2781:
2776:
2775:
2774:
2769:
2764:
2763:
2762:
2752:
2747:
2742:
2737:
2732:
2722:
2716:
2714:
2710:
2709:
2707:
2706:
2701:
2696:
2691:
2686:
2681:
2676:
2671:
2666:
2661:
2660:
2659:
2650:Charles Darwin
2647:
2646:
2645:
2633:
2628:
2622:
2620:
2614:
2613:
2611:
2610:
2605:
2600:
2595:
2590:
2588:Non-ecological
2585:
2580:
2575:
2570:
2565:
2560:
2555:
2549:
2547:
2541:
2540:
2538:
2537:
2528:
2519:
2505:
2503:
2497:
2496:
2494:
2493:
2488:
2487:
2486:
2481:
2476:
2471:
2466:
2456:
2451:
2446:
2441:
2436:
2431:
2426:
2421:
2416:
2411:
2406:
2405:
2404:
2394:
2389:
2384:
2379:
2378:
2377:
2372:
2361:
2359:
2352:
2351:
2349:
2348:
2347:
2346:
2341:
2339:nervous system
2336:
2331:
2326:
2318:
2317:
2316:
2311:
2306:
2301:
2296:
2291:
2281:
2276:
2271:
2265:
2263:
2256:
2255:
2253:
2252:
2247:
2242:
2237:
2232:
2231:
2230:
2220:
2219:
2218:
2213:
2212:
2211:
2206:
2196:
2191:
2186:
2181:
2176:
2175:
2174:
2169:
2159:
2149:
2144:
2143:
2142:
2132:
2127:
2122:
2117:
2116:
2115:
2105:
2100:
2099:
2098:
2088:
2082:
2080:
2073:
2072:
2070:
2069:
2064:
2059:
2054:
2049:
2044:
2038:
2036:
2032:
2031:
2029:
2028:
2023:
2018:
2013:
2012:
2011:
2006:
2001:
1991:
1986:
1981:
1976:
1971:
1970:
1969:
1964:
1954:
1949:
1944:
1943:
1942:
1932:
1927:
1922:
1917:
1911:
1909:
1901:
1900:
1898:
1897:
1896:
1895:
1885:
1880:
1879:
1878:
1873:
1863:
1862:
1861:
1851:
1846:
1841:
1839:Origin of life
1836:
1831:
1826:
1824:Microevolution
1821:
1819:Macroevolution
1816:
1811:
1806:
1805:
1804:
1794:
1789:
1784:
1779:
1774:
1769:
1764:
1759:
1757:Common descent
1754:
1753:
1752:
1742:
1737:
1735:Baldwin effect
1732:
1731:
1730:
1725:
1715:
1710:
1705:
1699:
1697:
1691:
1690:
1688:
1687:
1682:
1677:
1672:
1667:
1661:
1658:
1657:
1650:
1649:
1642:
1635:
1627:
1620:
1619:
1570:
1513:
1474:
1453:10019.1/122744
1411:
1374:
1323:
1274:
1247:
1187:
1130:
1087:
1044:
1033:(3): 384–410.
1017:
1000:
951:
928:
902:
878:
868:(4): 327–347.
840:
821:
810:(2): 203–219.
791:
764:(7): S65–S81.
748:
729:(4): 533–551.
694:
687:
663:
620:
607:10.1086/406755
574:
546:
544:
541:
539:
538:
533:
528:
523:
518:
513:
508:
503:
498:
490:
485:
480:
475:
470:
465:
460:
455:
450:
445:
440:
434:
432:
429:
424:
423:
420:
417:
414:
411:
408:
405:
392:
389:
383:
380:
377:
376:
357:
355:
341:Main article:
338:
335:
319:
316:
310:
307:
298:
295:
275:
272:
271:
270:
267:
230:Eurasian jay,
223:
220:
149:
146:
141:
138:
133:
132:
129:
122:
121:
118:
115:
112:
83:would mean to
65:
62:
41:Robert Trivers
15:
9:
6:
4:
3:
2:
3267:
3256:
3253:
3251:
3248:
3246:
3243:
3241:
3238:
3237:
3235:
3220:
3219:
3214:
3210:
3208:
3207:
3198:
3196:
3195:
3186:
3185:
3182:
3174:
3173:
3169:
3168:
3167:
3164:
3162:
3159:
3157:
3154:
3152:
3149:
3148:
3146:
3142:
3136:
3135:Robert Wright
3133:
3129:
3128:
3124:
3123:
3122:
3119:
3117:
3116:Frans de Waal
3114:
3112:
3111:Steven Pinker
3109:
3107:
3104:
3102:
3099:
3097:
3094:
3092:
3089:
3087:
3086:Anne Campbell
3084:
3083:
3081:
3077:
3071:
3068:
3066:
3063:
3058:
3055:
3051:
3048:
3047:
3046:
3043:
3042:
3041:
3038:
3036:
3033:
3029:
3026:
3025:
3024:
3021:
3019:
3016:
3014:
3011:
3009:
3008:Kin selection
3006:
3004:
3001:
2999:
2996:
2994:
2991:
2989:
2986:
2984:
2981:
2979:
2976:
2974:
2971:
2969:
2966:
2964:
2961:
2960:
2958:
2954:
2950:
2943:
2938:
2936:
2931:
2929:
2924:
2923:
2920:
2908:
2904:
2900:
2898:
2890:
2889:
2886:
2880:
2877:
2875:
2872:
2870:
2867:
2865:
2862:
2858:
2855:
2854:
2853:
2852:Phylogenetics
2850:
2848:
2845:
2843:
2840:
2838:
2835:
2833:
2830:
2826:
2823:
2821:
2818:
2816:
2813:
2812:
2811:
2808:
2806:
2803:
2801:
2798:
2796:
2793:
2792:
2790:
2786:
2780:
2777:
2773:
2770:
2768:
2765:
2761:
2758:
2757:
2756:
2755:Structuralism
2753:
2751:
2748:
2746:
2743:
2741:
2738:
2736:
2733:
2731:
2730:Catastrophism
2728:
2727:
2726:
2723:
2721:
2718:
2717:
2715:
2711:
2705:
2702:
2700:
2697:
2695:
2692:
2690:
2689:Neo-Darwinism
2687:
2685:
2682:
2680:
2677:
2675:
2672:
2670:
2667:
2665:
2662:
2658:
2657:
2653:
2652:
2651:
2648:
2644:
2643:
2639:
2638:
2637:
2634:
2632:
2629:
2627:
2624:
2623:
2621:
2619:
2615:
2609:
2606:
2604:
2603:Reinforcement
2601:
2599:
2596:
2594:
2591:
2589:
2586:
2584:
2581:
2579:
2576:
2574:
2571:
2569:
2566:
2564:
2561:
2559:
2556:
2554:
2551:
2550:
2548:
2546:
2542:
2536:
2535:Catastrophism
2532:
2529:
2527:
2526:Macromutation
2523:
2522:Micromutation
2520:
2518:
2514:
2510:
2507:
2506:
2504:
2502:
2498:
2492:
2489:
2485:
2482:
2480:
2477:
2475:
2472:
2470:
2467:
2465:
2462:
2461:
2460:
2457:
2455:
2452:
2450:
2447:
2445:
2442:
2440:
2437:
2435:
2432:
2430:
2429:Immune system
2427:
2425:
2422:
2420:
2417:
2415:
2412:
2410:
2407:
2403:
2400:
2399:
2398:
2395:
2393:
2390:
2388:
2385:
2383:
2380:
2376:
2373:
2371:
2368:
2367:
2366:
2363:
2362:
2360:
2358:
2353:
2345:
2342:
2340:
2337:
2335:
2332:
2330:
2327:
2325:
2322:
2321:
2319:
2315:
2312:
2310:
2307:
2305:
2302:
2300:
2297:
2295:
2292:
2290:
2289:symbiogenesis
2287:
2286:
2285:
2282:
2280:
2277:
2275:
2272:
2270:
2267:
2266:
2264:
2262:
2257:
2251:
2248:
2246:
2243:
2241:
2238:
2236:
2233:
2229:
2226:
2225:
2224:
2221:
2217:
2214:
2210:
2207:
2205:
2202:
2201:
2200:
2197:
2195:
2192:
2190:
2187:
2185:
2182:
2180:
2177:
2173:
2170:
2168:
2165:
2164:
2163:
2160:
2158:
2155:
2154:
2153:
2150:
2148:
2145:
2141:
2138:
2137:
2136:
2133:
2131:
2128:
2126:
2123:
2121:
2118:
2114:
2111:
2110:
2109:
2106:
2104:
2101:
2097:
2094:
2093:
2092:
2089:
2087:
2084:
2083:
2081:
2079:
2074:
2068:
2065:
2063:
2060:
2058:
2055:
2053:
2050:
2048:
2045:
2043:
2040:
2039:
2037:
2033:
2027:
2024:
2022:
2019:
2017:
2014:
2010:
2007:
2005:
2002:
2000:
1997:
1996:
1995:
1992:
1990:
1987:
1985:
1982:
1980:
1977:
1975:
1972:
1968:
1965:
1963:
1960:
1959:
1958:
1957:Kin selection
1955:
1953:
1952:Genetic drift
1950:
1948:
1945:
1941:
1938:
1937:
1936:
1933:
1931:
1928:
1926:
1923:
1921:
1918:
1916:
1913:
1912:
1910:
1908:
1902:
1894:
1891:
1890:
1889:
1886:
1884:
1881:
1877:
1874:
1872:
1869:
1868:
1867:
1864:
1860:
1857:
1856:
1855:
1852:
1850:
1847:
1845:
1842:
1840:
1837:
1835:
1832:
1830:
1827:
1825:
1822:
1820:
1817:
1815:
1812:
1810:
1807:
1803:
1800:
1799:
1798:
1795:
1793:
1790:
1788:
1785:
1783:
1780:
1778:
1775:
1773:
1770:
1768:
1765:
1763:
1760:
1758:
1755:
1751:
1748:
1747:
1746:
1743:
1741:
1738:
1736:
1733:
1729:
1726:
1724:
1721:
1720:
1719:
1716:
1714:
1711:
1709:
1706:
1704:
1701:
1700:
1698:
1696:
1692:
1686:
1683:
1681:
1678:
1676:
1673:
1671:
1668:
1666:
1663:
1662:
1659:
1655:
1648:
1643:
1641:
1636:
1634:
1629:
1628:
1625:
1615:
1611:
1606:
1601:
1597:
1593:
1589:
1585:
1581:
1574:
1566:
1562:
1557:
1552:
1548:
1544:
1540:
1536:
1532:
1528:
1524:
1517:
1509:
1505:
1501:
1497:
1493:
1489:
1485:
1478:
1467:
1463:
1459:
1454:
1449:
1445:
1441:
1437:
1433:
1426:
1424:
1415:
1407:
1403:
1399:
1395:
1391:
1387:
1386:
1378:
1370:
1366:
1362:
1358:
1354:
1350:
1346:
1342:
1338:
1334:
1327:
1319:
1315:
1310:
1305:
1301:
1297:
1293:
1289:
1285:
1278:
1270:
1266:
1262:
1258:
1251:
1243:
1239:
1234:
1229:
1225:
1221:
1217:
1213:
1209:
1205:
1201:
1194:
1192:
1183:
1179:
1174:
1169:
1165:
1161:
1157:
1153:
1149:
1145:
1141:
1134:
1126:
1122:
1118:
1114:
1110:
1106:
1102:
1098:
1091:
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1021:
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1012:
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992:
987:
982:
978:
974:
970:
966:
962:
955:
948:(1): 237–257.
947:
943:
939:
932:
924:
920:
916:
909:
907:
898:
894:
893:Sea Frontiers
887:
885:
883:
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867:
863:
856:
849:
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845:
836:
832:
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817:
813:
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688:0-19-929114-4
684:
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659:
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651:
647:
643:
639:
635:
631:
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443:Collaboration
441:
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428:
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315:
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258:is unlikely.
257:
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74:W.D. Hamilton
71:
61:
56:
54:
50:
46:
42:
37:
34:
30:
21:
3216:
3204:
3192:
3170:
3125:
3121:E. O. Wilson
3091:Noam Chomsky
3057:presociality
3017:
2949:Sociobiology
2864:Polymorphism
2847:Astrobiology
2795:Biogeography
2750:Saltationism
2740:Orthogenesis
2725:Alternatives
2654:
2640:
2573:Cospeciation
2568:Cladogenesis
2517:Saltationism
2474:Mating types
2397:Color vision
2382:Avian flight
2304:mitochondria
2042:Canalisation
1920:Biodiversity
1727:
1665:Introduction
1590:(6): 561–3.
1587:
1583:
1573:
1530:
1526:
1516:
1491:
1487:
1483:
1477:
1438:(1): 26–54.
1435:
1431:
1422:
1414:
1392:(1): 47–59.
1389:
1383:
1377:
1336:
1332:
1326:
1291:
1287:
1277:
1260:
1256:
1250:
1207:
1203:
1147:
1143:
1133:
1100:
1096:
1090:
1057:
1053:
1047:
1030:
1026:
1020:
1010:
1003:
968:
964:
954:
945:
941:
931:
914:
896:
892:
865:
861:
834:
830:
824:
807:
803:
761:
758:Parasitology
757:
751:
726:
722:
678:
636:(1): 17–52.
633:
629:
623:
598:
594:
560:
556:
550:
492:
473:Gift economy
425:
394:
385:
367:
363:adding to it
358:
330:
324:
321:
312:
302:Vampire bats
300:
297:Vampire bats
288:
283:Arctic terns
260:
256:selfish gene
252:
248:
245:
231:
216:
212:
208:
205:
201:
193:cleaner fish
186:
178:
170:
148:Cleaner fish
143:
134:
123:
106:
90:
78:
67:
57:
38:
32:
26:
3166:Steven Rose
3045:eusociality
2874:Systematics
2745:Mutationism
2563:Catagenesis
2491:Snake venom
2424:Eusociality
2402:in primates
2392:Cooperation
2320:In animals
2140:butterflies
2113:Cephalopods
2103:Brachiopods
2035:Development
2009:Mate choice
1762:Convergence
1745:Coevolution
1703:Abiogenesis
1533:(1): 1–17.
1494:(6): 1141.
563:: 189–210.
536:Tit for tat
488:Koinophilia
101:cooperation
93:tit for tat
53:game theory
49:tit for tat
45:cooperation
3234:Categories
3156:Leon Kamin
3079:Supporters
3070:Polyethism
2735:Lamarckism
2713:Philosophy
2636:David Hume
2598:Peripatric
2593:Parapatric
2578:Ecological
2558:Anagenesis
2553:Allopatric
2545:Speciation
2509:Gradualism
2434:Metabolism
2294:chromosome
2284:Eukaryotes
2062:Modularity
1979:Population
1905:Population
1866:Speciation
1844:Panspermia
1797:Extinction
1792:Exaptation
1767:Divergence
1740:Cladistics
1728:Reciprocal
1708:Adaptation
543:References
382:Exceptions
51:" used in
3245:Symbiosis
3144:Opponents
3050:evolution
3040:Sociality
3028:in humans
2869:Protocell
2720:Darwinism
2608:Sympatric
2357:processes
2245:Tetrapods
2194:Kangaroos
2120:Dinosaurs
2057:Inversion
2026:Variation
1947:Gene flow
1940:Inclusive
1750:Mutualism
1695:Evolution
1547:0022-5002
1508:0004-959X
1462:0003-4746
923:841865823
915:Symbiosis
601:: 35–57.
531:Symbiosis
331:B. tryoni
203:cleaner.
197:symbiosis
85:cooperate
3255:Altruism
3194:Category
2978:Ethology
2897:Category
2772:Vitalism
2767:Theistic
2760:Spandrel
2444:Morality
2439:Monogamy
2314:plastids
2279:Flagella
2235:Reptiles
2216:sea cows
2199:primates
2108:Molluscs
2086:Bacteria
1974:Mutation
1907:genetics
1883:Taxonomy
1829:Mismatch
1809:Homology
1723:Cheating
1718:Altruism
1614:21331239
1565:16812760
1466:Archived
1406:21449948
1385:Primates
1318:23282995
1242:23282995
1182:15058395
995:12396482
899:: 40–47.
870:Archived
837:: 89–96.
786:26816332
778:12396217
677:(2006).
615:19027999
431:See also
370:May 2021
318:Bacteria
309:Primates
140:Examples
70:altruism
3206:Commons
2788:Related
2618:History
2479:Meiosis
2414:Empathy
2409:Emotion
2309:nucleus
2250:Viruses
2240:Spiders
2152:Mammals
2135:Insects
1935:Fitness
1871:Species
1670:Outline
1605:3038063
1556:1349833
1369:4266889
1361:6709060
1341:Bibcode
1309:3574350
1233:3574350
1212:Bibcode
1173:1691571
1164:4142499
1125:4262191
1105:Bibcode
1082:5690147
1062:Bibcode
1054:Science
986:1691138
743:1462394
658:5875340
638:Bibcode
398:Trivers
173:) with
2956:Topics
2907:Portal
2583:Hybrid
2419:Ethics
2261:organs
2223:Plants
2209:lemurs
2204:humans
2189:horses
2179:hyenas
2167:wolves
2162:canids
2096:origin
1612:
1602:
1563:
1553:
1545:
1506:
1460:
1404:
1367:
1359:
1333:Nature
1316:
1306:
1240:
1230:
1204:Nature
1180:
1170:
1162:
1123:
1097:Nature
1080:
993:
983:
921:
784:
776:
741:
685:
656:
613:
497:(1902)
337:Humans
167:wrasse
64:Theory
2370:Death
2365:Aging
2344:brain
2130:Fungi
2091:Birds
2004:Fungi
1802:Event
1685:Index
1469:(PDF)
1428:(PDF)
1402:S2CID
1365:S2CID
1160:JSTOR
1121:S2CID
873:(PDF)
858:(PDF)
782:S2CID
739:S2CID
611:S2CID
2857:Tree
2329:hair
2269:Cell
2172:dogs
2157:cats
2147:Life
2125:Fish
2078:taxa
1610:PMID
1561:PMID
1543:ISSN
1504:ISSN
1458:ISSN
1357:PMID
1314:PMID
1238:PMID
1178:PMID
1078:PMID
1027:Ibis
991:PMID
919:OCLC
774:PMID
683:ISBN
654:PMID
2355:Of
2324:eye
2274:DNA
2259:Of
2076:Of
1600:PMC
1592:doi
1551:PMC
1535:doi
1496:doi
1486:".
1448:hdl
1440:doi
1436:158
1394:doi
1349:doi
1337:308
1304:PMC
1296:doi
1292:280
1265:doi
1228:PMC
1220:doi
1208:308
1168:PMC
1152:doi
1148:271
1113:doi
1101:198
1070:doi
1058:160
1035:doi
981:PMC
973:doi
969:269
812:doi
766:doi
762:124
731:doi
646:doi
603:doi
565:doi
365:.
27:In
3236::
1608:.
1598:.
1586:.
1582:.
1559:.
1549:.
1541:.
1531:64
1529:.
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1190:^
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1111:.
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1068:.
1056:.
1031:96
1029:.
989:.
979:.
967:.
963:.
946:11
944:.
940:.
905:^
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881:^
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864:.
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843:^
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833:.
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806:.
794:^
780:.
772:.
760:.
737:.
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697:^
666:^
652:.
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632:.
609:.
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577:^
559:.
55:.
31:,
3059:)
2941:e
2934:t
2927:v
2533:/
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2515:/
2511:/
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1639:t
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1594::
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1567:.
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1320:.
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1244:.
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1214::
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1107::
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1041:.
1037::
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818:.
814::
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768::
745:.
733::
691:.
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648::
640::
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617:.
605::
571:.
567::
561:9
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368:(
169:(
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
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