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'runaway hypothesis' can also refer ..

Fisher, R.A. (1930) The genetical theory of natural selection. Oxford: Clarendon Press.

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Sexual Selection - Side Box 1.1: Runaway Sexual Selection

Introduction: Based upon my personal experience visiting Basingstoke both before and after the construction of Festival Place, I predict that the hypothesis will be false....

Evolution 1 Name Course Institution Date The hypothesis proposes a runaway selection

If we continue this process, generation after generation, all of thedaughters of the choosy females have both the choice gene and the male traitgene. This means that females will be producing sons and daughters withboth choice and exaggerated trait genes together. Because the exaggeratedmales have an advantage in subsequent generations and because the choosyfemale genes are genetically correlated with the male trait, Female Choiceand the male trait spread, and they spread together, almost like a wildfire, or as Fisher termed a Runaway Process.

State the argument for the runaway selection hypothesis.

The obvious starting point purposive research for any runaway selection hypothesis discussion of sexual selection is to note.

Because the exagerated males have anadvantage, Female Choice and the male trait spread, and they spread togetherlinked by assortative mating, almost like a wild fire, or as Fisher termeda Runaway Process.

This theory was original proposed by Sir Ronald Fisher in which he believedthat a correlation would be set up between genes for female choice and thegenes for male traits, which would lead to a Runaway Process.We will also explore models of frequency dependent sexual selection thatexplain Male competition for Mates -- Evolutionary Game Theory. Let us assume that females come in two types: Notice that the ornamented male has a fitness of 3/2 and the plain malehas a fitness of 1/2.What happens each generation is that both the gene for female choiceand the male trait become correlated.

Animal Behavior: Chaseaway sexual selection

C. Badcock., ,Polity Press, Cambridge, 2000
H. Cronin., , CUP, Cambridge, 1992
C. R. Darwin., , John Murray, London, 1859
C. R. Darwin., ,John Murray, London, 1871
R. Dawkins., (new edition), OUP, 1989
R. A. Fisher, , ClarendonPress, Oxford, 1930
G. F. Miller., ‘Sexual Selection for Protean Expressiveness: A NewModel of Hominid Encephalization,’ 4th Annual meeting of the HumanBehavior and Evolution Society, Albuquerque, New Mexico, July 22-6, 1992
M. Ridley., ,Penguin, 1993 (reissued 2000)
S. Rose and H. Rose (eds.), , 2000
R. L. Trivers., ‘Parental Investment and Sexual Selection’,, ed. B. Campbell,Aldine-Atherton, Chicago, 1972

“Failure” is a semantically loaded word and should not imply that there are no evolutionary explanations for the observed outcomes in caste rearing and reproductive skew. However, these explanations invoke elements that are added to kin selection theory and do not follow from it. For example, caste-rearing nepotism would be absent if workers are constrained by an inability to distinguish their own patrilines from others. Without some means of kin recognition, kin selection could not “fail” as a hypothesis because it simply would not be relevant to the phenomenon at hand. Alternately, caste-rearing nepotism could create such within-colony conflict that overall colony productivity or survival is seriously reduced. Hence, conflict would not be selectively advantageous. This alternative explanation, again, does not follow from kin selection theory. No matter the overall cost, successful nepotists would always have a selective advantage relative to nonnepotists within colonies. It is only selection on the across-group level that could favor this ergonomic efficiency explanation for the absence of nepotism. The same two possibilities, constraint or ergonomics, could also explain why reproductive skew models do not adequately predict patterns of cooperative breeding (Nonacs and Hager, 2011). Nevertheless, recent work casts doubt on the constraint hypothesis as a broadly viable explanation. For example, individual ants produce genetically heritable hydrocarbon profiles that could, theoretically, be

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  • Fisherian runaway | Character structure | Mediander | …

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    This article lays out the runaway selection hypothesis land for evolutionists and ..

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    09/01/2018 · runaway hypothesis A hypothesis proposed by R

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No influence of sexual selection (the null hypothesis)

bias to the point where it is exactly offset by the relative mating advantage of the rare male sex (Trivers and Hare, 1976). Thus, if workers control sex investment ratios, a 3:1 female-to-male investment bias should result. Over 3 decades of evidence has solidly supported the core of the Trivers and Hare hypothesis (Nonacs, 1986; Bourke and Franks, 1995; Chapuis and Keller, 1999; Strassmann and Queller, 2007). Female-biased investment occurs frequently in species where the sister-brother relatedness asymmetry is present and far less often in species where it is absent. Within some species, there are both monogynous, monandrous colonies and others in which the relatedness difference between females and males is reduced or absent because of having multiple laying queens or one queen that uses sperm from multiple males. Extending Trivers’ observation predicts that such populations should exhibit split sex ratios, with the monogynous, monandrous colonies favoring females and the others favoring males (Boomsma and Grafen, 1990). A recent review (Meunier et al., 2008) found that within-colony relatedness asymmetries do significantly affect bias in sex investment as predicted by kin selection.

In runaway sexual selection, ..

Theory predicts these traits can be favored by runaway sexual selection, in which preference and display reinforce one another due to genetic correlation; or by good genes benefits, in which mate choice is advantageous because extreme displays indicate a well‐adapted genotype.

Does runaway sexual selection work in finite …

These four topics are chosen because I believe the underlying theory for the kin selective predictions is sound and that the possibility for kin nepotism to evolve is at least potentially present. This differs from two other cases, where kin selection predictions are suggested to have failed: the haplodiplody and monogamy hypotheses (Nowak et al., 2010). First, cooperative breeding has repeatedly evolved in the haplodiploid Hyme-noptera. Haplodiplody creates a genetic asymmetry, such that a female is more related to her full sister ( 0.75) than she is to her own offspring ( 0.5). Therefore, if a singly mated mother produces a female-biased offspring sex ratio, it is genetically more advantageous for a daughter to help her mother raise more sisters. However, the balance of evidence from existing species where cooperative breeding is facultative finds that such species are not monogamous, do not predictably bias sex ratios toward females, or both (Bourke and Franks, 1995). Hence, the haplodiploidy hypothesis is not a robust test of kin selection because the required patterns of genetic relatedness likely did not exist in the putative ancestors of eusocial species (Nonacs, 2010). The second example is the “monogamy hypothesis,” where cooperative breeding is predicted to be more likely to evolve in species where family groups are full siblings because of monogamy (Boomsma, 2009). However, a gene-based model for the evolution of cooperation found that helping actually often tended to spread more rapidly through populations with polygamy (Nonacs, 2011). This may be an instance where the underlying kin selection model actually produces erroneous predictions [as postulated by Nowak et al. (2010)].

19/12/2002 · Does runaway sexual selection work in ..

used to identify kin (van Zweden et al., 2010). However, such markers are readily transferred to create effective nestmate recognition rather than within-nest nepotism. This leaves only the group selection hypothesis as a plausible, if unsatisfying, explanation. It is unsatisfying because it is untestable in many cases; that is, if species A never exhibits caste-rearing nepotism, how can it be shown that it is because such behavior reduces overall colony productivity? Therefore, instead of relegating the solution as only explainable by difficult-to-test group selection, it is useful to reexamine kin selection predictions relative to the mechanistic aspects of exactly how individuals recognize or define other group mates as genetic kin. In essence, kin selection theory may accurately predict the outcomes for caste rearing and reproductive skew, but the predictions themselves may differ from earlier expectations.

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