Biology Commons^™

Lifetime Inclusive Fitness Effects Of Cooperative Polygamy In The Acorn Woodpecker, Walter D. Koenig, Sahas Barve, Joseph Haydock, Eric L. Walters

Biological Sciences Faculty Publications

Although over 50 y have passed since W. D. Hamilton articulated kin selection and inclusive fitness as evolutionary explanations for altruistic behavior, quantifying inclusive fitness continues to be challenging. Here, using 30 y of data and two alternative methods, we outline an approach to measure lifetime inclusive fitness effects of cooperative polygamy (mate-sharing or cobreeding) in the cooperatively breeding acorn woodpecker Melanerpes formicivorus. For both sexes, the number of offspring (observed direct fitness) declined while the number of young parented by related cobreeders (observed indirect fitness effect) increased with cobreeding coalition size. Combining these two factors, the observed inclusive …

Hypocrisy And Corruption: How Disparities In Power Shape The Evolution Of Social Control, Omar T. Eldakar, J. Oliver Kammeyer, Nikhil Nagabandi, Andrew C. Gallup

Biology Faculty Articles

Altruism presents an evolutionary paradox, as altruistic individuals are good for the group yet vulnerable to exploitation by selfish individuals. One mechanism that can effectively curtail selfishness within groups is punishment. Here, we show in an evolutionary game-theoretical model that punishment can effectively evolve and maintain high levels of altruism in the population, yet not all punishment strategies were equally virtuous. Unlike typical models of social evolution, we explicitly altered the extent to which individuals vary in their power over others, such that powerful individuals can more readily punish and escape the punishment of others. Two primary findings emerged. Under …

An Analysis Of Altruism, Sarah Siemens

Dialogue & Nexus

Scientists, freethinkers, and philosophers have attempted to find an explanation of the role of altruism in a natural world that is compatible to the dominantly accepted Darwinian principle of natural selection. Many postulates have been developed in an attempt to explain how self-sacrificial behaviors are cohesive within the “survival of the fittest” ideology. This has caused many scientists to broaden the definition of altruism to understand its components in the physical world. In order to understand how absolute altruism is solely found through God’s love, it is necessary to examine each subset of scientific altruism to reveal their differences. None …

Downward Mobility: Rediscovering A Narrative Of Justice, Josh Smith

Dialogue & Nexus

In this paper, social justice is defined by examining key perspectives of what it is from philosophy, theology, and biology. We will note where it is absent in order to discover what people deserve in a society governed by social justice. All of this will be evaluated in light of the Carmen Christi, the Hymn of Christ from Philippians 2. The example of Christ’s self-emptying (kenotic) refusal to consider equality with God (harpagmos) a thing to be grasped provides a crucial framework that enables us to emulate self-sacrificial altruism.

Altruism: Biological Rationale Vs. Christian Love Command, Chris Porter, Landry Guin

Dialogue & Nexus

The idea of altruism and self-sacrifice appears counter to a simple view of evolution. While a “survival of the fittest” mindset occurs in some Darwinian views, there are counter-examples of animals and humans with cooperative, pro-social, and even self-sacrificial behavior. Social animals such as bees and ants work for the community and provide for the queen due to a haploid-diploid system of genetic relatedness. Some humans sacrifice their lives and money to promote the well-being of others even without genetic relatedness and, rarely, without reciprocity. We will explore why human animals often help people who are less fortunate by giving …

Social Amoebae Mating Types Do Not Invest Unequally In Sexual Offspring, T E. Douglas, David C. Queller, Joan E. Strassmann

Biology Faculty Publications & Presentations

Unequal investment by different sexes in their progeny is common and includes differential investment in the zygote and differential care of the young. The social amoeba Dictyostelium discoideum has a sexual stage in which isogamous cells of any two of the three mating types fuse to form a zygote which then attracts hundreds of other cells to the macrocyst. The latter cells are cannibalized and so make no genetic contribution to reproduction. Previous literature suggests that this sacrifice may be induced in cells of one mating type by cells of another, resulting in a higher than expected production of macrocysts …

Fine-Scale Spatial Ecology Drives Kin Selection Relatedness Among Cooperating Amoebae, Jeff Smith, Joan E. Strassmann, David C. Queller

Biology Faculty Publications & Presentations

Cooperation among microbes is important for traits as diverse as antibiotic resistance, pathogen virulence, and sporulation. The evolutionary stability of cooperation against “cheater” mutants depends critically on the extent to which microbes interact with genetically similar individuals. The causes of this genetic social structure in natural microbial systems, however, are unknown. Here, we show that social structure among cooperative Dictyostelium amoebae is driven by the population ecology of colonization, growth, and dispersal acting at spatial scales as small as fruiting bodies themselves. Despite the fact that amoebae disperse while grazing, all it takes to create substantial genetic clonality within multicellular …

Kin Discrimination In Dictyostelium Social Amoebae, Joan E. Strassmann

Biology Faculty Publications & Presentations

Presentation delivered at the symposium Evidence of Taxa, Clone, and Kin Discrimination in Protists: Ecological and Evolutionary Implications, VII European Congress of Protistology, University of Seville, 5–10 September 2015, Seville Spain.

Evolved cooperation is stable only when the benefactor is compensated, either directly or through its relatives. Social amoebae cooperate by forming a mobile multicellular body in which, about 20% of participants ultimately die to form a stalk. This benefits the remaining individuals that become hardy spores at the top of the stalk, together making up the fruiting body. In studied species with stalked migration, P. violaceum, D. purpureum, and …

Concurrent Coevolution Of Intra-Organismal Cheaters And Resisters, S R. Levin, D A. Brock, David C. Queller, Joan E. Strassmann

Biology Faculty Publications & Presentations

The evolution of multicellularity is a major transition that is not yet fully understood. Specifically, we do not know whether there are any mechanisms by which multicellularity can be maintained without a single-cell bottleneck or other relatedness-enhancing mechanisms. Under low relatedness, cheaters can evolve that benefit from the altruistic behaviour of others without themselves sacrificing. If these are obligate cheaters, incapable of cooperating, their spread can lead to the demise of multicellularity. One possibility, however, is that cooperators can evolve resistance to cheaters. We tested this idea in a facultatively multicellular social amoeba, Dictyostelium discoideum. This amoeba usually exists as …

Fruiting Bodies Of The Social Amoeba Dictyostelium Discoideum Increase Spore Transport By Drosophila, Jeff Smith, David C. Queller, Joan E. Strassmann

Biology Faculty Publications & Presentations

Background: Many microbial phenotypes are the product of cooperative interactions among cells, but their putative fitness benefits are often not well understood. In the cellular slime mold Dictyostelium discoideum , unicellular amoebae aggregate when starved and form multicellular fruiting bodies in which stress-resistant spores are held aloft by dead stalk cells. Fruiting bodies are thought to be adaptations for dispersing spores to new feeding sites, but this has not been directly tested. Here we experimentally test whether fruiting bodies increase the rate at which spores are acquired by passing invertebrates.
Results: Drosophila melanogaster accumulate spores on their surfaces more quickly …

Levels Of Altruism, Martin Zwick, Jeffrey Alan Fletcher

Systems Science Faculty Publications and Presentations

The phenomenon of altruism extends from the biological realm to the human socio-cultural realm. This paper sketches a coherent outline of multiple types of altruism of progressively increasing scope that span these two realms and are grounded in an ever-expanding sense of"self." Discussion of this framework notes difficulties associated with altruisms at different levels. It links scientific ideas about the evolution of cooperation and about hierarchical order to perennial philosophical and religious concerns. It offers a conceptual background for inquiry into societal challenges that call for altruistic behavior, especially the challenge of environmental and social sustainability.

When Hawks Give Rise To Doves: The Evolution Of Enforcement Strategies, Omar Tonsi Eldakar, W. W. Driscoll, A. C. Gallup

Biology Faculty Articles

The question of how altruism can evolve despite its local disadvantage to selfishness has produced a wealth of theoretical and empirical research capturing the attention of scientists across disciplines for decades. One feature that has remained consistent through this outpouring of knowledge has been that researchers have looked to the altruists themselves for mechanisms by which altruism can curtail selfishness. An alternative perspective may be that just as altruists want to limit selfishness in the population, so may the selfish individuals themselves. These alternative perspectives have been most evident in the fairly recent development of enforcement strategies. Punishment can effectively …

Altruism And The Administration Of The Universe: Kirtley Fletcher Mather On Science And Values, Edward B. Davis

Biology Educator Scholarship

Few American scientists have devoted as much attention to religion and science as Harvard geologist Kirtley Fletcher Mather (1888-1978). Responding to antievolutionism during the 1920s, he taught Sunday School classes, assisted in defending John Scopes, and wrote Science in Search of God (1928). Over the next 40 years, Mather explored the place of humanity in the universe and the presence of values in light of what he often called "the administration of the universe," a term and concept he borrowed from his former teacher, geologist Thomas Chrowder Chamberlin. Human values, including cooperation and altruism, had emerged in such a context: …

Population Structure Influences Sexual Conflict In Wild Populations Of Water Striders., Omar Tonsi Eldakar, Michael J. Dlugos, Galen P. Holt, David Sloan Wilson, John W. Pepper

Biology Faculty Articles

In sexual conflict, aggressive males frequently diminish the long-term reproductive success of females in efforts to gain a short-term advantage over rival males. This short-term advantage can selectively favour high-exploitation males. However, just as the over-exploitation of resources can lead to local extinction, the over-exploitation of females in the form of harassment by aggressive males can yield similar consequences resulting in reduced female fecundity, increased female mortality and overall decline in mating activity. This outcome may often be prevented by selection acting at multiple levels of biological organization. Directional selection favouring aggressive exploitation within groups can be balanced by directional …

The Role Of Multilevel Selection In The Evolution Of Sexual Conflict In The Water Strider Aquarius Remigis, Omar Tonsi Eldakar, David Sloan Wilson, Michael J. Dlugos, John W. Pepper

Biology Faculty Articles

In evolution, exploitative strategies often create a paradox in which the most successful individual strategy “within” the group is also the most detrimental strategy “for” the group, potentially resulting in extinction. With regard to sexual conflict, the overexploitation of females by harmful males can yield similar consequences. Despite these evolutionary implications, little research has addressed why sexual conflict does not ultimately drive populations to extinction. One possibility is that groups experiencing less sexual conflict are more productive than groups with greater conflict. However, most studies of sexual conflict are conducted in a single isolated group, disregarding the potential for selection …

Chimpanzees Do Not Take Advantage Of Very Low Cost Opportunities To Deliver Food To Unrelated Group Members, Jennifer Vonk, Sarah F. Brosnan, Joan B. Silk, Joseph Heinrich, Amanda S. Richardson, Susan P. Lambeth, Steven J. Schapiro, Daniel J. Povinelli

Faculty Publications

We conducted experiments on two populations of chimpanzees, Pan troglodytes, to determine whether they would take advantage of opportunities to provide food rewards to familiar group members at little cost to themselves. In both of the experiments described here, chimpanzees were able to deliver identical rewards to themselves and to other members of their social groups. We compared the chimpanzees' behaviour when they were paired with another chimpanzee and when they were alone. If chimpanzees are motivated to provide benefits to others, they are expected to consistently deliver rewards to others and to distinguish between the partner-present and partner-absent …

Emotions And Actions Associated With Altruistic Helping And Punishment, Omar Tonsi Eldakar, David Sloan Wilson, Rick O'Gorman

Biology Faculty Articles

Evolutionary altruism (defined in terms of fitness effects) exists in the context of punishment in addition to helping. We examine the proximate psychological mechanisms that motivate altruistic helping and punishment, including the effects of genetic relatedness, potential for future interactions, and individual differences in propensity to help and punish. A cheater who is a genetic relative provokes a stronger emotional reaction than a cheater who is a stranger, but the behavioral response is modulated to avoid making the transgression public in the case of cheating relatives. Numerous behavioral differences are not accompanied by emotional differences, suggesting that other psychological mechanisms …

The Evolution Of Alarm Calls: Altruism Or Manipulation?, Eric Charnov, John R. Krebs

Biology Faculty & Staff Publications

No abstract provided.