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Herron MD, Zamani-Dahaj SA, Ratcliff WC. Trait heritability in major transitions. BMC Biol 2018; 16:145. [PMID: 30545356 PMCID: PMC6293664 DOI: 10.1186/s12915-018-0612-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 11/20/2018] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Increases in biological complexity and the origins of life's hierarchical organization are described by the "major transitions" framework. A crucial component of this paradigm is that after the transition in complexity or organization, adaptation occurs primarily at the level of the new, higher-level unit. For collective-level adaptations to occur, though, collective-level traits-properties of the group, such as collective size-must be heritable. Since collective-level trait values are functions of lower-level trait values, collective-level heritability is related to particle-level heritability. However, the nature of this relationship has rarely been explored in the context of major transitions. RESULTS We examine relationships between particle-level heritability and collective-level heritability for several functions that express collective-level trait values in terms of particle-level trait values. For clonal populations, when a collective-level trait value is a linear function of particle-level trait values and the number of particles per collective is fixed, the heritability of a collective-level trait is never less than that of the corresponding particle-level trait and is higher under most conditions. For more complicated functions, collective-level heritability is higher under most conditions, but can be lower when the environment experienced by collectives is heterogeneous. Within-genotype variation in collective size reduces collective-level heritability, but it can still exceed particle-level heritability when phenotypic variance among particles within collectives is large. These results hold for a diverse sample of biologically relevant traits. CONCLUSIONS Rather than being an impediment to major transitions, we show that, under a wide range of conditions, the heritability of collective-level traits is actually higher than that of the corresponding particle-level traits. High levels of collective-level trait heritability thus arise "for free," with important implications not only for major transitions but for multilevel selection in general.
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Affiliation(s)
- Matthew D. Herron
- School of Biological Sciences, Georgia Institute of Technology, North Avenue, Atlanta, GA 30332 USA
| | - Seyed A. Zamani-Dahaj
- School of Physics, Georgia Institute of Technology, North Avenue, Atlanta, GA 30332 USA
| | - William C. Ratcliff
- School of Biological Sciences, Georgia Institute of Technology, North Avenue, Atlanta, GA 30332 USA
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Wade MJ, McCauley DE. EXTINCTION AND RECOLONIZATION: THEIR EFFECTS ON THE GENETIC DIFFERENTIATION OF LOCAL POPULATIONS. Evolution 2017; 42:995-1005. [PMID: 28581169 DOI: 10.1111/j.1558-5646.1988.tb02518.x] [Citation(s) in RCA: 358] [Impact Index Per Article: 51.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/1987] [Accepted: 03/23/1988] [Indexed: 11/27/2022]
Affiliation(s)
- Michael J. Wade
- Department of Biology University of Chicago Chicago IL 60637
| | - David E. McCauley
- Department of General Biology Vanderbilt University Nashville TN 37235
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Affiliation(s)
- Michael J Wade
- University of Chicago, Department of Biology, Chicago, Illinois, 60637
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McCauley DE, Wade MJ. GROUP SELECTION: THE GENETIC AND DEMOGRAPHIC BASIS FOR THE PHENOTYPIC DIFFERENTIATION OF SMALL POPULATIONS OF TRIBOLIUM CASTANEUM. Evolution 2017; 34:813-821. [DOI: 10.1111/j.1558-5646.1980.tb04020.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/1979] [Revised: 12/29/1979] [Indexed: 11/30/2022]
Affiliation(s)
- David E. McCauley
- Department of Biology; University of Chicago; Chicago Illinois 60637
| | - Michael J. Wade
- Department of Biology; University of Chicago; Chicago Illinois 60637
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Goodnight CJ. ON THE EFFECT OF FOUNDER EVENTS ON EPISTATIC GENETIC VARIANCE. Evolution 2017; 41:80-91. [PMID: 28563758 DOI: 10.1111/j.1558-5646.1987.tb05772.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/1985] [Accepted: 09/22/1986] [Indexed: 11/30/2022]
Abstract
Mayr (1963) proposed that small isolated propagules from a large panmictic population would occasionally undergo a genetic revolution due to loss of genetic variability. More recently Templeton (1980a) has suggested that founder events may be much more important in systems that have strong epistasis. Because of the work of these and other authors it becomes an interesting theoretical problem to study the distribution of epistatic variance in a population following a founder event. In the model presented here measures of coancestry (Cockerham, 1967, 1984; Cockerham and Weir, 1973; Weir and Cockerham, 1973, 1977; Tachida and Cockerham, unpubl.) are used to examine the effect of founder events on additive-by-additive epistasis. Using this approach, the coancestries, or intraclass correlations, within individuals and within demes, together with the genetic variance components in the ancestral population are used to obtain the variance within and among demes following a founder event. Examples are analyzed for single founder events of 1-25 individuals and multiple founder events of two individuals. Following a single founder event, the contribution of the additive variance to the variance within demes relative to the additive variance in the ancestral population is always less than one. However, the contribution of epistatic variance to the variance within demes relative to the epistatic variance in the ancestral population is always greater than one. Thus, while a founder event decreases the contribution of additive variance to the variance within demes, it increases the contribution of epistatic variance to the variance within demes. The contribution of epistatic variance to the variance among demes following a single founder event is not qualitatively different from the contribution of additive variance to the variance among demes. These results indicate that epistatic variance is less likely than additive variance to cause a genetic revolution following a single founder event. When populations undergo multiple founder events the situation changes considerably. Epistatic variance may contribute as much as four times its original value to the variance among demes, while additive variance can contribute maximally twice its original value to the variance among demes. Thus, epistasis, which is relatively unimportant following a single founder event, may have major evolutionary implications if drift is allowed to continue for several generations.
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Affiliation(s)
- Charles J Goodnight
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, 60680
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Reyment RA. PHENOTYPIC EVOLUTION IN A CRETACEOUS FORAMINIFER. Evolution 2017; 36:1182-1199. [DOI: 10.1111/j.1558-5646.1982.tb05488.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/1981] [Revised: 01/31/1982] [Indexed: 11/27/2022]
Affiliation(s)
- Richard A. Reyment
- Paleontologiska Institutionen; Uppsala Universitet; Box 558 S751 22 Uppsala Sweden
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Pray LA, Goodnight CJ. THE EFFECT OF INBREEDING ON PHENOTYPIC VARIANCE IN THE RED FLOUR BEETLE TRIBOLIUM CASTANEUM. Evolution 2017; 51:308-313. [PMID: 28568778 DOI: 10.1111/j.1558-5646.1997.tb02414.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/1996] [Accepted: 07/03/1996] [Indexed: 11/30/2022]
Affiliation(s)
- Leslie A Pray
- Department of Biology, Marsh Life Science Building, University of Vermont, Burlington, Vermont, 05405
| | - Charles J Goodnight
- Department of Biology, Marsh Life Science Building, University of Vermont, Burlington, Vermont, 05405
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Goodnight CJ. POPULATION DIFFERENTIATION AND THE TRANSMISSION OF DENSITY EFFECTS BETWEEN GENERATIONS. Evolution 2017; 42:399-403. [DOI: 10.1111/j.1558-5646.1988.tb04144.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/1987] [Accepted: 08/12/1987] [Indexed: 11/27/2022]
Affiliation(s)
- Charles J. Goodnight
- Department of Biological Sciences University of Illinois at Chicago P.O. Box 4348 Chicago IL 60680
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Wade MJ, Goodnight CJ. PERSPECTIVE: THE THEORIES OF FISHER AND WRIGHT IN THE CONTEXT OF METAPOPULATIONS: WHEN NATURE DOES MANY SMALL EXPERIMENTS. Evolution 2017; 52:1537-1553. [PMID: 28565332 DOI: 10.1111/j.1558-5646.1998.tb02235.x] [Citation(s) in RCA: 183] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/1997] [Accepted: 09/08/1998] [Indexed: 11/30/2022]
Affiliation(s)
- Michael J. Wade
- Department of Biology Indiana University Bloomington Indiana 47405
| | - Charles J. Goodnight
- Department of Biology, 115 Marsh Life Science Building University of Vermont, Burlington Vermont 05405‐0086
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Moore FBG, Tonsor SJ. A SIMULATION OF WRIGHT'S SHIFTING-BALANCE PROCESS: MIGRATION AND THE THREE PHASES. Evolution 2017; 48:69-80. [PMID: 28567795 DOI: 10.1111/j.1558-5646.1994.tb01295.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/1992] [Accepted: 03/05/1993] [Indexed: 11/26/2022]
Abstract
Wright partitioned the shifting-balance process into three phases. Phase one is the shift of a deme within a population to the domain of a higher adaptive peak from that of the historical peak. Phase two is mass selection within a deme towards that higher peak. Phase three is the conversion of additional demes to the higher peak. The migration rate between demes is critical for the existence of phases one and three. Phase one requires small effective population sizes, hence low migration rates. Phase three is optimal under high migration rates that spread the most-fit genotype from deme to deme. Thus, a population-wide peak shift requires intermediate levels of migration. By altering the rates of phases one and three, migration affects the predominant direction of mass selection within a population. This study examines the degree to which migration, through its effects on phases one and three, determines the probability of a simulated population arriving at its genotypic optimum after 12,000 generations. These simulations reveal that there is a range of migration rates for which an entire population might be expected to shift to a higher peak. Below m = 0.001 peak shifts occur frequently (phases I and II) but are not successfully exported out of subpopulations (phase III), and above 0.01 peak shifts within demes (phase I and II), required to initiate phase III, become increasingly uncommon. Because it is unlikely that real populations will have uniform migration rates from generation to generation, the probable effects of varying migration rates on broadening the range of conditions producing peak shifts are discussed.
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Affiliation(s)
- Francisco B-G Moore
- Kellogg Biological Station, Hickory, Corners, Michigan, 49060.,Department of Zoology, Michigan State University, East Lansing, Michigan, 48825
| | - Stephen J Tonsor
- Kellogg Biological Station, Hickory Corners, Michigan, 49060.,Department of Botany and Plant Pathology, Michigan State University, East Lansing, Michigan, 48825
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Wade MJ. GROUP SELECTION: MIGRATION AND THE DIFFERENTIATION OF SMALL POPULATIONS. Evolution 2017; 36:949-961. [DOI: 10.1111/j.1558-5646.1982.tb05465.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/1980] [Revised: 12/28/1981] [Indexed: 11/28/2022]
Affiliation(s)
- Michael J. Wade
- Department of Biology; University of Chicago; Chicago Illinois 60637
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Goodnight CJ. EXPERIMENTAL STUDIES OF COMMUNITY EVOLUTION I: THE RESPONSE TO SELECTION AT THE COMMUNITY LEVEL. Evolution 2017; 44:1614-1624. [DOI: 10.1111/j.1558-5646.1990.tb03850.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/1989] [Accepted: 12/21/1989] [Indexed: 12/01/2022]
Affiliation(s)
- Charles J. Goodnight
- Department of Zoology University of Vermont Marsh Life Science Building Burlington VT 05405‐0086 USA
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Goodnight CJ. EXPERIMENTAL STUDIES OF COMMUNITY EVOLUTION II: THE ECOLOGICAL BASIS OF THE RESPONSE TO COMMUNITY SELECTION. Evolution 2017; 44:1625-1636. [PMID: 28564304 DOI: 10.1111/j.1558-5646.1990.tb03851.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/1989] [Accepted: 12/21/1989] [Indexed: 11/29/2022]
Abstract
Community selection, defined as the differential proliferation and/or extinction of communities, can bring about a response that may be qualitatively different from the response to selection acting at lower levels. This is because community selection can result in genetic changes in all of the species within the community by acting on the interaction among species. In the experiment presented here, a series of one generation assays were performed on the coevolved communities of two species of flour beetles, Tribolium castaneum and T. confusum, discussed by Goodnight (1990). Two community assays and one single-species assay were performed. Taken together, these provide insights into the genetic basis of the response to community selection. The first community assay involved measuring the selected traits on the original coevolved communities that had been subjected to community selection. This assay indicated that all of the selection treatments resulted in a significant response to selection in the original coevolved communities. The single-species assay involved separating the coevolved communities into their constituent single-species populations and again measuring the selected traits on these populations. None of the single-species populations exhibited a significant response to selection; thus the responses to community selection observed in the first community assay are expressed only in a community context. The second community assay again involved separating the coevolved communities into their constituent single-species populations; however, in this assay a competitor of the opposite species that had never been exposed to community selection was added to each population to form a "reconstructed" community. The results of this assay were that for two traits, emigration rate in T. castaneum and emigration rate in T. confusum, the genetic identity of the competing species did not affect the response to selection. This indicates that the competing species was acting like a nonevolving part of the environment. For the other two traits measured, population size in T. castaneum and population size in T. confusum, the results were very different. For these traits there was no detectable response to selection in the reconstructed communities. This indicates that for these traits the response to selection cannot be attributed to a genetic change in either species independently of the other species in the community. Rather it resides in the interaction between the two species.
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Affiliation(s)
- Charles J Goodnight
- Department of Zoology, University of Vermont, Marsh Life Science Building, Burlington, VT, 05405-0086, USA
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Pray LA. THE EFFECT OF INBREEDING ON POPULATION-LEVEL GENETIC CORRELATIONS IN THE RED FLOUR BEETLE TRIBOLIUM CASTANEUM. Evolution 2017; 51:614-619. [PMID: 28565364 DOI: 10.1111/j.1558-5646.1997.tb02449.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/1996] [Accepted: 11/01/1996] [Indexed: 11/30/2022]
Affiliation(s)
- Leslie A Pray
- Department of Biology, University of Vermont, Burlington, Vermont 05405
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Stevens L. THE GENETICS AND EVOLUTION OF CANNIBALISM IN FLOUR BEETLES (GENUS TRIBOLIUM). Evolution 2017; 43:169-179. [PMID: 28568492 DOI: 10.1111/j.1558-5646.1989.tb04215.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/1987] [Accepted: 07/28/1988] [Indexed: 11/30/2022]
Abstract
Cannibalism plays a major role in population regulation in Tribolium confusum, accounting for up to tenfold differences in population size between different genetic strains. I characterized the within- and between-strain genetic variation for cannibalism using standard quantitative-genetic methods. The four laboratory strains studied have similar birth and death rates but differ in their strain-specific cannibalistic tendencies. The cannibalism rates of the strains were stable for more than 60 generations of laboratory husbandry. I found considerable genetic variation for cannibalism within each strain. A genetic analysis of the between-strain differences in each of three types of cannibalism (larvae eating eggs, adults eating eggs, and adults eating pupae) showed that all three cannibalism pathways are autosomally inherited and exhibit minor degrees of dominance. Adult cannibalism of eggs and larval cannibalism of eggs appear to be genetically correlated. The differences between the "high" and "low" cannibalism strains appear to be polygenic for two kinds of cannibalism, larvae eating eggs and adults eating pupae. However, strain differences in adult cannibalism of eggs may be due to only two loci. The stability of the between-strain differences for more than 60 generations, the additive nature of inheritance, and the demonstration of considerable within-strain genetic variation suggest that cannibalism may be selectively neutral or under stabilizing selection with many adaptive peaks.
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Affiliation(s)
- Lori Stevens
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, 60680
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Wade MJ. GENETIC VARIANCE FOR RATE OF POPULATION INCREASE IN NATURAL POPULATIONS OF FLOUR BEETLES, TRIBOLIUM SPP. Evolution 2017; 45:1574-1584. [PMID: 28564129 DOI: 10.1111/j.1558-5646.1991.tb02664.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/1989] [Accepted: 03/05/1991] [Indexed: 11/27/2022]
Abstract
The genetic and ecological effects of population subdividsion were investigated for two wild strains of Tribolium castaneum and two wild strains of T. confusum and compared with the effects of population subdivision on the synthetic laboratory strain of T. castaneum (c-SM), used extensively in earlier experiments. For the c-SM strain, it has been shown repeatedly, for a variety of different population structures (different combinations of effective numbers, Ne , and migration rates, m), that large heritable differences in population growth rate arise among demes during 10 to 15 generations of population subdivision. Because this laboratory strain was synthesized by mass mating several "inbred" strains in 1973 (80 to 100 generations ago), it is possible that it has genetic variation for fitness (measured as the heritable variance among demes in the rate of population increase) unusually large compared to natural populations of flour beetles. In this paper, I report that natural populations of flour beetle exhibit as much or more phenotypic and genetic variation in the effects of population structure on fitness than the laboratory strain, c-SM. The observation of substantial heritable variation for fitness in natural populations is unexpected under additive theory and may be indicative of nonadditive genetic variance.
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Affiliation(s)
- Michael J Wade
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, 60637, USA
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Craig DM. GROUP SELECTION VERSUS INDIVIDUAL SELECTION: AN EXPERIMENTAL ANALYSIS. Evolution 2017; 36:271-282. [DOI: 10.1111/j.1558-5646.1982.tb05041.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/1980] [Revised: 07/29/1981] [Indexed: 11/29/2022]
Affiliation(s)
- David M. Craig
- Department of Biological Sciences University of Illinois at Chicago Circle Box 4348 Chicago Illinois 60680
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Muir WM, Bijma P, Schinckel A. Multilevel selection with kin and non-kin groups, experimental results with Japanese quail (Coturnix japonica). Evolution 2013; 67:1598-606. [PMID: 23730755 PMCID: PMC3744746 DOI: 10.1111/evo.12062] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 01/12/2013] [Indexed: 11/28/2022]
Abstract
An experiment was conducted comparing multilevel selection in Japanese quail for 43 days weight and survival with birds housed in either kin (K) or random (R) groups. Multilevel selection significantly reduced mortality (6.6% K vs. 8.5% R) and increased weight (1.30 g/MG K vs. 0.13 g/MG R) resulting in response an order of magnitude greater with Kin than Random. Thus, multilevel selection was effective in reducing detrimental social interactions, which contributed to improved weight gain. The observed rates of response did not differ significantly from expected, demonstrating that current theory is adequate to explain multilevel selection response. Based on estimated genetic parameters, group selection would always be superior to any other combination of multilevel selection. Further, near optimal results could be attained using multilevel selection if 20% of the weight was on the group component regardless of group composition. Thus, in nature the conditions for multilevel selection to be effective in bringing about social change maybe common. In terms of a sustainability of breeding programs, multilevel selection is easy to implement and is expected to give near optimal responses with reduced rates of inbreeding as compared to group selection, the only requirement is that animals be housed in kin groups.
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The group-level consequences of sexual conflict in multigroup populations. PLoS One 2011; 6:e26451. [PMID: 22039491 PMCID: PMC3200328 DOI: 10.1371/journal.pone.0026451] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 09/27/2011] [Indexed: 11/19/2022] Open
Abstract
In typical sexual conflict scenarios, males best equipped to exploit females are favored locally over more prudent males, despite reducing female fitness. However, local advantage is not the only relevant form of selection. In multigroup populations, groups with less sexual conflict will contribute more offspring to the next generation than higher conflict groups, countering the local advantage of harmful males. Here, we varied male aggression within-and between-groups in a laboratory population of water striders and measured resulting differences in local population growth over a period of three weeks. The overall pool fitness (i.e., adults produced) of less aggressive pools exceeded that of high aggression pools by a factor of three, with the high aggression pools essentially experiencing no population growth over the course of the study. When comparing the fitness of individuals across groups, aggression appeared to be under stabilizing selection in the multigroup population. The use of contextual analysis revealed that overall stabilizing selection was a product of selection favoring aggression within groups, but selected against it at the group-level. Therefore, this report provides further evidence to show that what evolves in the total population is not merely an extension of within-group dynamics.
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Nongenetic and non-Darwinian evolution. Behav Brain Sci 2010. [DOI: 10.1017/s0140525x00036396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Abstract
AbstractIn both biology and the human sciences, social groups are sometimes treated as adaptive units whose organization cannot be reduced to individual interactions. This group-level view is opposed by a more individualistic one that treats social organization as a byproduct of self-interest. According to biologists, group-level adaptations can evolve only by a process of natural selection at the group level. Most biologists rejected group selection as an important evolutionary force during the 1960s and 1970s but a positive literature began to grow during the 1970s and is rapidly expanding today. We review this recent literature and its implications for human evolutionary biology. We show that the rejection of group selection was based on a misplaced emphasis on genes as “replicators” which is in fact irrelevant to the question of whether groups can be like individuals in their functional organization. The fundamental question is whether social groups and other higher-level entities can be “vehicles” of selection. When this elementary fact is recognized, group selection emerges as an important force in nature and what seem to be competing theories, such as kin selection and reciprocity, reappear as special cases of group selection. The result is a unified theory of natural selection that operates on a nested hierarchy of units.The vehicle-based theory makes it clear that group selection is an important force to consider in human evolution. Humans can facultatively span the full range from self-interested individuals to “organs” of group-level “organisms.” Human behavior not only reflects the balance between levels of selection but it can also alter the balance through the construction of social structures that have the effect of reducing fitness differences within groups, concentrating natural selection (and functional organization) at the group level. These social structures and the cognitive abilities that produce them allow group selection to be important even among large groups of unrelated individuals.
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The maintenance of behavioral diversity in human societies. Behav Brain Sci 2010. [DOI: 10.1017/s0140525x00036438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Empirically equivalent theories. Behav Brain Sci 2010. [DOI: 10.1017/s0140525x0003630x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Driving both ways: Wilson & Sober's conflicting criteria for the identification of groups as vehicles of selection. Behav Brain Sci 2010. [DOI: 10.1017/s0140525x00036116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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