Abstract
This chapter is the first of five comprising Part III. Though, as in Chap. 6, we have previously allowed some lexical analyses to interpolate Part II’s historical-empirical thrust, Part III is predominately statistical, even as it continues to review relevant literature and history. Though, consistent with the mandate of this monograph, we aim ultimately to establish the reality of human group selection, this initial chapter alone treats chimpanzees. To thoroughgoing evolutionists, the relevance will be self-evident; we only add that establishing evidence of group selection in such a highly related species foundationally supports the empirical argument for human group selection, as presented in the four subsequent chapters constituting Part III of this volume.
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Notes
- 1.
Chimpanzees inhabit multimale-multifemale communities characterized for their fission-fusion dynamics, within which individuals decrease the intensity of intragroup competition by foraging or exploring in subgroups (Aureli et al., 2008; Lehmann & Boesch, 2004; Lehmann, Korstjens, & Dunbar, 2007). Chimpanzees are polygynandrous, with males and females copulating with multiple individuals (Van Schaik, 2016). Although male reproductive skewness has been reported, males also employ an array of alternative mating tactics such as sperm competition (Dixson, 2012; Muller & Pilbeam, 2017) and collective mate guarding (Watts, 1998). In contrast to other primates living in polygynous societies, where a single male has a reproductive monopoly, chimpanzees display an attenuation in their sexual dimorphism (e.g., in canine size; Plavcan, 2001, 2012; Plavcan, Van Schaik, & Kappeler, 1995). Chimpanzees exhibit sex-biased dispersal, with females abandoning their natal group after reaching sexual maturity (Langergraber, Mitani, & Vigilant, 2009; Mitani, Watts, & Muller, 2002; Pusey, 1980). Male philopatry has considerable social sequelae such as the development of intracommunity coalitions and alliances (Chapais, 2009; Gilby et al., 2013; Wilson & Glowacki, 2017).
- 2.
- 3.
The annexation of this area generated several behavioral changes. For example, Ngogo chimpanzees spent over 30% of the observation time foraging and socializing in the captured region, a pattern that lasted for at least five months (Mitani et al., 2010).
- 4.
Julian, Badfoot, and Light Brown, in 1991, 1998, and 2001
- 5.
A similar approach was adopted in previous publications. For example, Wrangham et al. (2006) generated a comprehensive cross-site database describing instances of intracommunity and intercommunity lethal aggression from five sites and nine communities. Following traditional epidemiological procedures, the authors estimated the sites had a median mortality rate of 69 per 100,000 per year, based on observed and inferred cases, and 287 per 100,000 per year, including suspected cases (Wrangham et al., 2006). Communities also exhibited noticeable differences in killing rates. Even though the total rate across communities ranged from 125 to 306 per 100,000 per year, some communities experienced higher rates than others (Wrangham et al., 2006). Kahama, for example, reached a value of 12,000 per 100,000 per year, while Sonso did not experience any attack (Wrangham et al., 2006). Across communities, adult and adolescent males were often the victims of these attacks, with a rate of 355 per 100,000 per year, followed by infants and juveniles with 92, and adult and adolescent females with 28. This value stands in contrast to the frequency of intracommunity lethal aggression, with infants and juveniles displaying a median rate of 429 per 100,000 per year, as compared to adult and adolescent males with 254 per 100,000 per year (Wrangham et al., 2006).
- 6.
Though this pattern generalizes to other chimpanzee communities, regional differences exist between Eastern and Western communities. In contrast to chimpanzees from Gombe, female chimpanzees at the Taï National Park experience less severe, life-threatening attacks (Boesch et al., 2008). Moreover, the frequency of sexual interactions between neighboring communities at Taï is five times greater than that of Eastern communities (Boesch et al., 2008). These behavioral differences could be attributed to socioecological variations. Taï chimpanzees forage in larger parties and exhibit more social cohesion (Boesch, 1991; Boesch et al., 2008). Higher levels of gregariousness allow vulnerable individuals to be rescued by nearby supporters during intercommunity encounters, a phenomenon uncommon in Eastern communities (Boesch et al., 2008). Taï’s larger group size could also be attributed to higher predation rates (Boesch, 1991). It is worth noting, however, that even under circumstances of greater social cohesion, intercommunity killings do occur (Boesch et al., 2007, 2008).
- 7.
Lanchester’s “linear law” predicts that the largest group will not deploy all its units in a battle. Victory will depend on the relative difference in fighting force between the factions (Wilson, Britton, & Franks, 2002). According to the “square law,” if one of the groups outnumbers the other, the largest group should allocate all its units in a concentrated attack. The numerical advantage will influence the outcome of the conflict (Wilson et al., 2002).
- 8.
Given that previous publications have used reproductive success as a proxy for fitness in chimpanzees (Gilby et al., 2013), the present study employed a similar approach by using the males’ paternity success as a surrogate for the individual’s fitness.
- 9.
We would like to thank Robyn Stea for help in coding these data and JohnMichael Jurgensen for his feedback on this chapter.
- 10.
Even though traditional factor analyses rely on the extraction of latent variables from observable indicators across individuals (an R-type matrix), it is also statistically feasible to determine underlying groups by examining the correlations between individuals across occasions (an S-type matrix; Gorsuch, 2015).
- 11.
Langergraber et al. (2017) squared this variable. The present chapter retained this transformation.
- 12.
Researchers have also argued that the persistence of lethal intercommunity competition arises from the low costs accrued by raiding males when targeting vulnerable or solitary individuals in the rival group. Even though the experimental and observational evidence endorses perspectives concentrating on examining the low fitness costs of ambushes and incursions, such as the imbalance of power hypothesis, these results should not discourage researchers from further examining the fitness benefits obtained by raiding males. Similarly, future studies should consider the role of multilevel selection in the evolution of chimpanzee intercommunity competition.
- 13.
See Sober and Wilson (1998), for a detailed overview of the logic inconsistencies associated with the parsimony argument.
References
Amsler, S. J. (2010). Energetic costs of territorial boundary patrols by wild chimpanzees. American Journal of Primatology: Official Journal of the American Society of Primatologists, 72(2), 93–103.
Aureli, F., Schaffner, C. M., Boesch, C., Bearder, S. K., Call, J., Chapman, C. A., et al. (2008). Fission-fusion dynamics: New research frameworks. Current Anthropology, 49(4), 627–654.
Boesch, C. (1991). The effects of leopard predation on grouping patterns in forest chimpanzees. Behaviour, 117(3–4), 220–242.
Boesch, C., Crockford, C., Herbinger, I., Wittig, R., Moebius, Y., & Normand, E. (2008). Intergroup conflicts among chimpanzees in Tai National Park: Lethal violence and the female perspective. American Journal of Primatology: Official Journal of the American Society of Primatologists, 70(6), 519–532.
Boesch, C., Head, J., Tagg, N., Arandjelovic, M., Vigilant, L., & Robbins, M. M. (2007). Fatal chimpanzee attack in Loango National Park, Gabon. International Journal of Primatology, 28(5), 1025–1034.
Chapais, B. (2009). Primeval kinship: How pair-bonding gave birth to human society. Cambridge: Harvard University Press.
Damuth, J., & Heisler, I. L. (1988). Alternative formulations of multilevel selection. Biology and Philosophy, 3(4), 407–430.
Dixson, A. F. (2012). Primate sexuality. New York: Oxford University Press.
Feldblum, J. T., Manfredi, S., Gilby, I. C., & Pusey, A. E. (2018). The timing and causes of a unique chimpanzee community fission preceding Gombe's “four‐year war”. American Journal of Physical Anthropology, 166(3), 730–744.
Gilby, I. C., Brent, L. J., Wroblewski, E. E., Rudicell, R. S., Hahn, B. H., Goodall, J., et al. (2013). Fitness benefits of coalitionary aggression in male chimpanzees. Behavioral Ecology and Sociobiology, 67(3), 373–381.
Glowacki, L., Wilson, M., & Wrangham, R. (2017). The evolutionary anthropology of war. Journal of Economic Behavior and Organization. https://doi.org/10.1016/j.jebo.2017.09.014
Goodall, J. (1986). The chimpanzees of Gombe: Patterns of behavior. Cambridge, MA: Belknap Press of Harvard University Press.
Gorsuch, R. L. (2015). Factor analysis. New York: Psychology Press.
Heisler, I. L., & Damuth, J. (1987). A method for analyzing selection in hierarchically structured populations. The American Naturalist, 130(4), 582–602.
Herbinger, I., Papworth, S., Boesch, C., & Zuberbühler, K. (2009). Vocal, gestural and locomotor responses of wild chimpanzees to familiar and unfamiliar intruders: A playback study. Animal Behaviour, 78(6), 1389–1396.
Kitchen, D. M., & Beehner, J. C. (2007). Factors affecting individual participation in group-level aggression among non-human primates. Behaviour, 144(12), 1551–1581.
Lanchester, F. W. (1916). Aircraft in warfare: The dawn of the fourth arm. London: Constable limited.
Langergraber, K., Mitani, J., & Vigilant, L. (2009). Kinship and social bonds in female chimpanzees (Pan troglodytes). American Journal of Primatology: Official Journal of the American Society of Primatologists, 71(10), 840–851.
Langergraber, K. E., Watts, D. P., Vigilant, L., & Mitani, J. C. (2017). Group augmentation, collective action, and territorial boundary patrols by male chimpanzees. Proceedings of the National Academy of Sciences, 114(28), 7337–7342.
Langergraber, K. E., Watts, D. P., Vigilant, L., & Mitani, J. C. (2018). Data from: Group augmentation, collective action, and territorial boundary patrols by male chimpanzees. Dryad, Dataset. https://doi.org/10.5061/dryad.kk33f
Lehmann, J., & Boesch, C. (2004). To fission or to fusion: Effects of community size on wild chimpanzee (Pan troglodytes verus), social organization. Behavioral Ecology and Sociobiology, 56(3), 207–216.
Lehmann, J., Korstjens, A. H., & Dunbar, R. I. M. (2007). Fission–fusion social systems as a strategy for coping with ecological constraints: A primate case. Evolutionary Ecology, 21(5), 613–634.
Lemoine, S., Boesch, C., Preis, A., Samuni, L., Crockford, C., & Wittig, R. M. (2020a). Group dominance increases territory size and reduces neighbour pressure in wild chimpanzees. Royal Society Open Science, 7(5), 200577. https://doi.org/10.1098/rsos.200577
Lemoine, S., Preis, A., Samuni, L., Boesch, C., Crockford, C., & Wittig, R. M. (2020b). Between-group competition impacts reproductive success in wild chimpanzees. Current Biology, 30(2), 312–318.
Manson, J. H., & Wrangham, R. W. (1991). Intergroup aggression in chimpanzees and humans. Current Anthropology, 32(4), 369–390.
Mitani, J. C., & Watts, D. P. (2005). Correlates of territorial boundary patrol behaviour in wild chimpanzees. Animal Behaviour, 70(5), 1079–1086.
Mitani, J. C., Watts, D. P., & Amsler, S. J. (2010). Lethal intergroup aggression leads to territorial expansion in wild chimpanzees. Current Biology, 20(12), R507–R508.
Mitani, J. C., Watts, D. P., & Muller, M. N. (2002). Recent developments in the study of wild chimpanzee behavior. Evolutionary Anthropology: Issues, News, and Reviews, 11(1), 9–25.
Muller, M. N., & Pilbeam, D. R. (2017). The evolution of the human mating system. In M. N. Muller, R. W. Wrangham, & D. R. Pilbeam (Eds.), Chimpanzees and human evolution (pp. 383–426). Cambridge, MA: Harvard University Press.
Nishida, T., Hamai, M., Hasegawa, T., Hiraiwa-Hasegawa, M., Hosaka, K., Hunt, K. D., et al. (2003). Demography, female life history, and reproductive profiles among the chimpanzees of Mahale. American Journal of Primatology, 59(3), 99–121.
Nishida, T., Hiraiwa-Hasegawa, M., Hasegawa, T., & Takahata, Y. (1985). Group extinction and female transfer in wild chimpanzees in the Mahale National Park, Tanzania. Zeitschrift für Tierpsychologie, 67(1–4), 284–301.
Okasha, S. (2004). Multilevel selection and the partitioning of covariance: A comparison of three approaches. Evolution, 58(3), 486–494.
Okasha, S. (2006). Evolution and the levels of selection. Oxford: Oxford University Press.
Pandit, S. A., Pradhan, G. R., Balashov, H., & Van Schaik, C. P. (2016). The conditions favoring between-community raiding in chimpanzees, bonobos, and human foragers. Human Nature, 27(2), 141–159.
Plavcan, J. M. (2001). Mating systems, intrasexual competition and sexual dimorphism in primates. In P. C. Lee (Ed.), Comparative primate socioecology (pp. 241–269). New York: Cambridge University Press.
Plavcan, J. M. (2012). Sexual size dimorphism, canine dimorphism, and male-male competition in primates. Human Nature, 23(1), 45–67.
Plavcan, J. M., Van Schaik, C. P., & Kappeler, P. M. (1995). Competition, coalitions and canine size in primates. Journal of Human Evolution, 28(3), 245–276.
Power, M. (1991). The egalitarians-human and chimpanzee: An anthropological view of social organization. New York: Cambridge University Press.
Pradhan, G. R., Pandit, S. A., & Van Shaik, C. P. (2014). Why do chimpanzee males attack the females of neighboring communities? American Journal of Physical Anthropology, 155(3), 430–435.
Pusey, A. E. (1980). Inbreeding avoidance in chimpanzees. Animal Behaviour, 28(2), 543–552.
Sober, E., & Wilson, D. S. (1998). Unto others: The evolution and psychology of unselfish behavior. Cambridge: Harvard University Press.
Sussman, R. W. (2013). Why the legend of the killer ape never dies: The enduring powers of cultural beliefs to distort our view of human nature. In D. P. Fry (Ed.), War, peace, and human nature: The convergence of evolutionary and cultural views (pp. 97–111). New York: Oxford University Press.
Van Schaik, C. P. (2016). The primate origins of human nature. Hoboken: Wiley.
Watts, D. P. (1998). Coalitionary mate guarding by male chimpanzees at Ngogo, Kibale National Park, Uganda. Behavioral Ecology and Sociobiology, 44(1), 43–55.
Watts, D. P., Muller, M. N., Amsler, S. J., Mbabazi, G., & Mitani, J. C. (2006). Lethal intergroup aggression by chimpanzees in Kibale National Park, Uganda. American Journal of Primatology, 68(2), 161–180.
Williams, J. M., Lonsdorf, E. V., Wilson, M. L., Schumacher-Stankey, J., Goodall, J., & Pusey, A. E. (2008). Causes of death in the Kasekela chimpanzees of Gombe National Park, Tanzania. American Journal of Primatology: Official Journal of the American Society of Primatologists, 70(8), 766–777.
Williams, J. M., Oehlert, G. W., Carlis, J. V., & Pusey, A. E. (2004). Why do male chimpanzees defend a group range? Animal Behaviour, 68(3), 523–532.
Wilson, M. L. (2013). Chimpanzees, warfare, and the invention of peace. In D. P. Fry (Ed.), War, peace, and human nature: The convergence of evolutionary and cultural views (pp. 361–388). New York: Oxford University Press.
Wilson, M. L., Boesch, C., Fruth, B., Furuichi, T., Gilby, I. C., Hashimoto, C., et al. (2014). Lethal aggression in Pan is better explained by adaptive strategies than human impacts. Nature, 513(7518), 414–417.
Wilson, M. L., Britton, N. F., & Franks, N. R. (2002). Chimpanzees and the mathematics of battle. Proceedings of the Royal Society of London. Series B: Biological Sciences, 269(1496), 1107–1112.
Wilson, M. L., & Glowacki, L. (2017). Violent cousins: Chimpanzees, humans, and the roots of war. In M. N. Muller, R. W. Wrangham, & D. R. Pilbeam (Eds.), Chimpanzees and human evolution (pp. 464–508). Cambridge, MA: Harvard University Press.
Wilson, M. L., Hauser, M. D., & Wrangham, R. W. (2001). Does participation in intergroup conflict depend on numerical assessment, range location, or rank for wild chimpanzees? Animal Behaviour, 61(6), 1203–1216.
Wilson, M. L., Kahlenberg, S. M., Wells, M., & Wrangham, R. W. (2012). Ecological and social factors affect the occurrence and outcomes of intergroup encounters in chimpanzees. Animal Behaviour, 83(1), 277–291.
Wrangham, R. W. (1999). Evolution of coalitionary killing. Yearbook of Physical Anthropology, 42, 1–30.
Wrangham, R. W., & Glowacki, L. (2012). Intergroup aggression in chimpanzees and war in nomadic hunter-gatherers. Human Nature, 23(1), 5–29.
Wrangham, R. W., Wilson, M. L., & Muller, M. N. (2006). Comparative rates of violence in chimpanzees and humans. Primates, 47(1), 14–26.
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Peñaherrera-Aguirre, M., Figueredo, A.J., Hertler, S.C. (2020). Chimpanzee Intercommunity Conflict: Fitness Outcomes, Power Imbalances, and Multilevel Selection. In: Multilevel Selection. Palgrave Macmillan, Cham. https://doi.org/10.1007/978-3-030-49520-6_8
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