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<span id="zyzz"></span>[[File:Buff.jpg|thumb|right|One popular sex icon for men: Zyzz, died young of sudden cardiac arrest from too much steroid use to make himself look hyper-masculine. He was not a [[reproductive success]].]] | <span id="zyzz"></span>[[File:Buff.jpg|thumb|right|One popular sex icon for men: Zyzz, died young of sudden cardiac arrest from too much steroid use to make himself look hyper-masculine. He was not a [[reproductive success]].]][[File:Peacock courting peahen.jpg|alt=|thumb|"The females may be dull looking, but they're very picky." A peacock courting a peahen]] | ||
'''Fisherian runaway''' is a mechanism by which [[sexual selection]] leads to exaggerated physical traits (ornamentation), potentially to the extent of [[maladaptiveness]] and reduced population viability,<ref>Encyclopedia of Ecology, By Brian D. Fath, page 316 https://books.google.com/books?hl=en&lr=&id=x1h7DwAAQBAJ&oi=fnd&pg=PA310&dq=%22fisherian+runaway%22+extinction+%22selection%22&ots=cq04BIA2Lf&sig=Otp5RbC3B_5W1ZR7Q3zGjPOe7uA#v=onepage&q=fisherian%20runaway&f</ref> or even extinction.<ref>The evolution of sexual strategy in modern humans: an interdisciplinary approach by Collins, Kendra Marie, https://studyres.com/doc/2550939/--california-state-university</ref><ref>Moen et al., 1999</ref> | '''Fisherian runaway''' is a mechanism by which [[sexual selection]] leads to exaggerated physical traits (ornamentation), potentially to the extent of [[maladaptiveness]] and reduced population viability,<ref>Encyclopedia of Ecology, By Brian D. Fath, page 316 https://books.google.com/books?hl=en&lr=&id=x1h7DwAAQBAJ&oi=fnd&pg=PA310&dq=%22fisherian+runaway%22+extinction+%22selection%22&ots=cq04BIA2Lf&sig=Otp5RbC3B_5W1ZR7Q3zGjPOe7uA#v=onepage&q=fisherian%20runaway&f</ref> or even extinction.<ref>The evolution of sexual strategy in modern humans: an interdisciplinary approach by Collins, Kendra Marie, https://studyres.com/doc/2550939/--california-state-university</ref><ref>Moen et al., 1999</ref> | ||
The name Fisherian runaway derives from the originator of the concept, Ronald Fisher, the 20th century British statistician, geneticist, eugenicist and racialist. | The name Fisherian runaway derives from the originator of the concept, Ronald Fisher, the 20th century British statistician, geneticist, eugenicist and racialist. | ||
==Explanation== | ==Explanation== | ||
=== Mechanism === | === Mechanism === | ||
Fisherian runaway is a selection process occurring over many generations, in which the one sex (either male or female) becomes more choosy about a heritable trait for the simple reason that it will make the offspring more attractive. As the the choosiness for the trait increases, the selective pressure to prefer the trait increases too, forming a [https://en.wikipedia.org/wiki/Positive_feedback_loop positive feedback loop]. In response to the increased choosiness, the other sex evolves to enlarge, overcomplicate or beautify that trait in efforts of becoming more attractive, eliciting [https://en.wikipedia.org/wiki/Supernormal_stimulus super-stimuli] in the opposite sex. The exponential nature of positive feedback loops exerts a strong selection pressure that the resulting exaggerate may reduce mobility and increase vulnerability to predators and to sudden environmental changes. | Fisherian runaway is a selection process occurring over many generations, in which the one sex (either male or female) becomes more choosy about a heritable trait for the simple reason that it will make the offspring more attractive. As the the choosiness for the trait increases, the selective pressure to prefer the trait increases too, forming a [https://en.wikipedia.org/wiki/Positive_feedback_loop positive feedback loop]. In response to the increased choosiness, the other sex evolves to enlarge, overcomplicate or beautify that trait in efforts of becoming more attractive, eliciting [https://en.wikipedia.org/wiki/Supernormal_stimulus super-stimuli] in the opposite sex. The exponential nature of positive feedback loops exerts a strong selection pressure that the resulting exaggerate may reduce mobility and increase vulnerability to predators and to sudden environmental changes. | ||
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=== Intelligence === | === Intelligence === | ||
Miller suggested strong positive-feedback processes in sexual selection to have given rise to higher human cognition, which he regards as too advanced for the necessities of human survival. Much of male courtship may consists in eliciting super stimuli in women by cognitive performance such as poetry, dancing, art and humor.<ref>https://ontherapyaspse.files.wordpress.com/2012/04/geoffrey-miller-the-mating-mind.pdf</ref> | Miller suggested strong positive-feedback processes in sexual selection to have given rise to higher human cognition, which he regards as too advanced for the necessities of human survival. Much of male courtship may consists in eliciting super stimuli in women by cognitive performance such as poetry, dancing, art and humor.<ref>https://ontherapyaspse.files.wordpress.com/2012/04/geoffrey-miller-the-mating-mind.pdf</ref> | ||
== Animal examples == | |||
<gallery mode="packed" widths="400" heights="200"> | |||
File:1920px-Male Peafowl (Peacock) at China National GeneBank, Shenzhen.jpg|A male Peafowl with completely useless plumage | |||
File:Skull of Sabre-Toothed Tiger - Museum of Anthropology - La Paz - Baja California Sur - Mexico (23835305595).jpg|The Sabre-Toothed Tiger evolved comically large teeth | |||
File:Irish Elk Side.jpg|Skeleton of the Irish Elk | |||
</gallery> | |||
Despite there being debate on the role of sexual selection causing extinction without other factors present, everyone agrees that, combined with environmental factors, sexual selection can and does cause "evolutionary suicide" or extinction due to runaway selection.<ref>https://biology.stackexchange.com/questions/239/is-there-any-evidence-that-sexual-selection-may-lead-to-extinction-of-species</ref> | |||
Theoretic models suggest extinction cannot happen due to sexual selection without sudden environmental changes and as long the ornamented individual bears the cost.<ref>"Sexy to die for? Sexual selection and risk of extinction" by Hanna Kokko and Robert Brooks, Ann. Zool. Fennici 40: 207-219. [[https://www.jstor.org/stable/23736526 Abstract]]</ref> | |||
Certain species have been theorized to go extinct partly due to runaway female sexual selection. The Irish elk’s extinction was at least in part, due to runaway sexual selection. Female Irish elk selected male elk with larger bodies as well as increasingly larger antlers. Some recovered antlers measure nine feet across and weigh over 90 pounds. The extreme nutritious cost to grow such huge antlers, coupled with the burden of such a heavy load, were more than the males could handle, particularly as their food source density decreased during environmental changes.<ref>The evolution of sexual strategy in modern humans: an interdisciplinary approach by Collins, Kendra Marie, https://studyres.com/doc/2550939/--california-state-university</ref> In this case, natural selection would have favored males with smaller bodies and antlers needing fewer nutritional resources, however the sexual selection pressures were so strong, and had become so fixed in a positive feedback loop, that it ultimately cost the loss of the entire species.<ref>Moen et al., 1999</ref> | |||
==Humans== | |||
Even though human females are more choosy in accordance to [[Bateman's principle]], both sexes are ornamented. Women have [[Boobs|permanently swollen breasts]],<ref>https://doi.org/10.1016/j.evolhumbehav.2010.02.005</ref> an hour glass shaped body etc., men have a V-shaped upper body, more toned muscles, beards, very large penises compared to other great apes, and [[:Category:Aesthetics|various other features]].<ref>https://www.sciencedirect.com/science/article/abs/pii/S1090513810000279</ref> Both sexes have clearly defined [[Hairline|hairlines]] and very clear skin. None of these features have survival value besides being good looking, so they're likely sexually selected, likely mostly by aesthetic selection common to many higher animals,<ref>https://www.apa.org/monitor/oct06/pretty</ref> and possibly by feedback loops like Fisherian runaway and sensory bias,<ref>Fuller, R. C., Houle, D., & Travis, J. 2005. ''Sensory Bias as an Explanation for the Evolution of Mate Preferences.'' [[https://www.jstor.org/stable/10.1086/444443 Abstract]]</ref> leading to exaggeration and strengthened sexual dimorphism.<ref>https://www.sciencedirect.com/science/article/abs/pii/S1090513810000279</ref> Though dominant and masculine features like large beards and a deep, intimidating voice may also serve the intimidation of other males.<ref>https://www.sciencedirect.com/science/article/abs/pii/S1090513810000279</ref><ref>http://larspenke.eu/pdfs/Kordsmeyer_et_al_2018_-_Intra-_vs_intersexual_selection_on_human_males.pdf</ref> | |||
The fact that men have only reproduced half as often as women<ref>https://incels.wiki/w/Scientific_Blackpill#Before_.27enforced_monogamy.27.2C_women.27s_effective_population_size_was_up_to_17x_larger_than_men.27s</ref> suggests only the most dominant men were involved in selecting women's ornament. | |||
==Criticism== | ==Criticism== | ||