Difference between revisions of "Evolution of the foreskin"

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[[Image:Charles-Darwin.jpg|right|thumb|Charles Darwin.]]
 
[[Image:Charles-Darwin.jpg|right|thumb|Charles Darwin.]]
  
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Millions of years of evolution have fashioned the human body into a model of refinement, elegance, and efficiency, with every part having a function and purpose. Evolution has determined that mammals' genitals should be sheathed in a protective, responsive, multipurpose foreskin. Every normal human being is born with a foreskin. In females, it protects the glans of the clitoris; in males, it protects the glans of the penis. Thus, the foreskin is an essential part of human sexual anatomy.<ref>{{REFjournal
+
Millions of years of evolution have fashioned the human body into a model of refinement, elegance, and efficiency, with every part having a function and purpose. Evolution has determined that mammals' genitals should be sheathed in a [[Immunological and protective function of the foreskin| protective]], responsive, multipurpose [[foreskin]]. Every normal human being is born with a [[foreskin]]. In females, it protects the glans of the [[clitoris]]; in males, it protects the [[glans]] of the [[penis]]. Thus, the foreskin is an essential part of human sexual anatomy.<ref>{{REFjournal
 
  |last=Fleiss
 
  |last=Fleiss
 
  |first=Paul M.
 
  |first=Paul M.
 +
|init=PM
 +
|author-link=Paul M. Fleiss
 
  |title=The Case Against Circumcision
 
  |title=The Case Against Circumcision
 
  |journal=Mothering: The Magazine of Natural Family Living
 
  |journal=Mothering: The Magazine of Natural Family Living
 +
|season=Winter
 
  |volume=
 
  |volume=
 
  |issue=
 
  |issue=
 
  |pages=36-45
 
  |pages=36-45
−
  |url=http://www.mothersagainstcirc.org/fleiss.html
+
  |url=https://www.cirp.org/news/1997/1997-12-01_Mothering.php
 
  |quote=
 
  |quote=
−
|pubmedID=
+
 
−
|pubmedCID=
 
−
|DOI=
 
 
  |date=1997
 
  |date=1997
−
  |accessdate=
+
  |accessdate=2024-12-22
 
}}</ref>
 
}}</ref>
  
−
Over the last 65 million years, the prepuce has offered reproductive advantages. Although advocates of mass circumcision hypothesize that the prepuce represents a design flaw, it is more likely that sexual selection has refined the external genitalia of each primate species for reproductive excellence.<ref name="cold-mcgrath">{{REFbook
+
Over the last 65 million years, the [[prepuce]] has offered reproductive advantages. Although advocates of mass [[circumcision]] hypothesize that the prepuce represents a design flaw, it is more likely that sexual selection has refined the external genitalia of each primate species for reproductive excellence.<ref name="cold-mcgrath">{{REFbook
 
  |last=Cold
 
  |last=Cold
−
  |first=Christopher
+
  |first=Christopher J.
 +
|init=CJ
 +
|author-link=Christopher J. Cold
 
  |last2=McGrath
 
  |last2=McGrath
 
  |first2=Kenneth
 
  |first2=Kenneth
 +
|init2=K
 
  |author2-link=Ken McGrath
 
  |author2-link=Ken McGrath
 
  |year=1999
 
  |year=1999
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== Evolution ==
 
== Evolution ==
 +
===Natural selection===
 +
Charles Darwin (1859) has done an admirable work in introducing the principle of ''natural selection'' to explain evolution.<ref>{{REFbook
 +
|last=Darwin
 +
|first=Charles
 +
|init=
 +
|year=1859
 +
|title=The Origin of Species
 +
|chapter=[https://www.gutenberg.org/files/1228/1228-h/1228-h.htm#chap04 Chapter Four: Natural Selection]
 +
|url=
 +
|scope=
 +
|location=London
 +
|publisher=John Murray
 +
|ISBN=
 +
|accessdate=2024-12-18
 +
}}</ref>
 +
 
=== Morphology ===
 
=== Morphology ===
−
 
+
The [[prepuce]] has been well conserved by evolution.<ref name="cold-mcgrath"/> In primates, the [[foreskin]] has been present in the genitalia of both sexes of mammals for at least 65 million years and likely has been present for over 100 millions years of evolution, based on its commonality as an anatomical feature in mammals.<ref>{{REFbook
−
The prepuce has been well conserved by evolution.<ref name="cold-mcgrath"/> In primates, the foreskin has been present in the genitalia of both sexes of mammals for at least 65 million years and likely has been present for over 100 millions years of evolution, based on its commonality as an anatomical feature in mammals.<ref>{{REFbook
 
 
  |last=Martin
 
  |last=Martin
 
  |first=Robert D.
 
  |first=Robert D.
 +
|init=RD
 
  |year=1990
 
  |year=1990
 
  |title=Primate Origins and Evolution: A Phylogenetic Reconstruction
 
  |title=Primate Origins and Evolution: A Phylogenetic Reconstruction
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  |pages=
 
  |pages=
 
  |location=New Jersey
 
  |location=New Jersey
−
  |publisher=Princeton University Press
+
  |publisher={{UNI|Princeton University|PU}} Press
 
  |isbn=978-0-691-08565-4
 
  |isbn=978-0-691-08565-4
 
  |quote=
 
  |quote=
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  |last=Diamond
 
  |last=Diamond
 
  |first=Jared M.
 
  |first=Jared M.
 +
|init=JM
 
  |year=1997
 
  |year=1997
 
  |title=Why Sex is Fun: The Evolution of Human Sexuality
 
  |title=Why Sex is Fun: The Evolution of Human Sexuality
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  |last=Darwin
 
  |last=Darwin
 
  |first=Charles
 
  |first=Charles
 +
|init=C
 
  |year=1871
 
  |year=1871
 
  |title=The Descent of Man and Selection in Relation to Sex
 
  |title=The Descent of Man and Selection in Relation to Sex
−
  |url=
+
  |url=https://darwin-online.org.uk/converted/published/1874_Descent_F944/1874_Descent_F944.html
 
  |editor=
 
  |editor=
 
  |edition=
 
  |edition=
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  |isbn=1148750932
 
  |isbn=1148750932
 
  |quote=
 
  |quote=
−
  |accessdate=
+
  |accessdate=2024-12-22
 
  |note=
 
  |note=
−
}}</ref><ref>{{REFbook
+
}}</ref><ref name="short1981">{{REFbook
 
  |last=Short
 
  |last=Short
−
  |first=RV
+
  |init=RV
 
  |year=1981
 
  |year=1981
 
  |title=Reproductive Biology of the Great Apes: Comparative and Biomedical Perspectives
 
  |title=Reproductive Biology of the Great Apes: Comparative and Biomedical Perspectives
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  |accessdate=
 
  |accessdate=
 
  |note=
 
  |note=
−
}}</ref> It has been proposed that the foreskin evolved to facilitate masturbation.<ref>{{REFjournal
+
}}</ref> It has been proposed that the [[foreskin]] evolved to facilitate [[masturbation]],<ref name="cox1995">{{REFjournal
 
  |last=Cox
 
  |last=Cox
 
  |first=Guy
 
  |first=Guy
 +
|init=G
 
  |title=De virginibus puerisque: The function of the human foreskin considered from an evolutionary perspective
 
  |title=De virginibus puerisque: The function of the human foreskin considered from an evolutionary perspective
 
  |journal=Med Hypotheses
 
  |journal=Med Hypotheses
 
  |volume=45
 
  |volume=45
 
  |issue=6
 
  |issue=6
−
  |pages=617-21
+
  |pages=617-621
−
  |url=
+
  |url=https://www.sciencedirect.com/science/article/abs/pii/0306987795902481
 
  |quote=
 
  |quote=
 
  |pubmedID=8771059
 
  |pubmedID=8771059
 
  |pubmedCID=
 
  |pubmedCID=
−
  |DOI=
+
  |DOI=10.1016/0306-9877(95)90248-1
 
  |date=1995
 
  |date=1995
−
  |accessdate=
+
  |accessdate=2024-12-22
−
}}</ref> The human prepuce has an increase in corpuscular innervation and concomitant decrease in corpuscular receptors in the human glans compared to the prepuce and glans of lower primates, demonstrating an evolutionary advancement.<ref>{{REFjournal
+
}}</ref> but, in accordance with Darwin's principles of survival, it is more likely that the [[gliding action]] of the male prepuce facilitates penetration and fertilization of the female.<ref>{{REFjournal
 +
|last=Taves
 +
|first=
 +
|init=DR
 +
|author-link=
 +
|etal=no
 +
|title=The intromission function of the foreskin
 +
|trans-title=
 +
|journal=Medical Hypotheses
 +
|location=
 +
|date=2002-08
 +
|volume=59
 +
|issue=2
 +
|pages=180-2
 +
|url=https://www.cirp.org/library/anatomy/taves1/10
 +
|archived=
 +
|quote=
 +
|pubmedID=12208206
 +
|pubmedCID=
 +
|DOI=10.1016/s0306-9877(02)00250-5
 +
|accessdate=2024-12-22
 +
}}</ref> The human prepuce has an increase in corpuscular innervation and concomitant decrease in corpuscular receptors in the human [[glans]] compared to the prepuce and glans of lower primates, demonstrating an evolutionary advancement.<ref name="nadler1995">{{REFjournal
 
  |last=Nadler
 
  |last=Nadler
 
  |first=Ronald D.
 
  |first=Ronald D.
 +
|init=RD
 
  |title=Proximate and ultimate influences on the regulation of mating in the great apes
 
  |title=Proximate and ultimate influences on the regulation of mating in the great apes
 
  |journal=American Journal of Primatology
 
  |journal=American Journal of Primatology
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  |issue=2
 
  |issue=2
 
  |pages=93-102
 
  |pages=93-102
−
  |url=
+
  |url=https://onlinelibrary.wiley.com/doi/10.1002/ajp.1350370204
 
  |quote=
 
  |quote=
−
  |pubmedID=
+
  |pubmedID=31936943
 
  |pubmedCID=
 
  |pubmedCID=
 
  |DOI=10.1002/ajp.1350370204
 
  |DOI=10.1002/ajp.1350370204
 
  |date=1995
 
  |date=1995
−
  |accessdate=
+
  |accessdate=2024-12-22
 
}}</ref><ref>{{REFjournal
 
}}</ref><ref>{{REFjournal
 
  |last=Williams-Ashman
 
  |last=Williams-Ashman
−
  |first=H.G.
+
  |init=HG
 
  |title=Enigmatic features of penile development and functions
 
  |title=Enigmatic features of penile development and functions
 
  |journal=Perspectives in Biology and Medicine
 
  |journal=Perspectives in Biology and Medicine
 
  |volume=33
 
  |volume=33
 
  |issue=
 
  |issue=
−
  |pages=335-74
+
  |pages=335-374
−
  |url=
+
  |url=https://muse.jhu.edu/article/402394
 
  |quote=
 
  |quote=
 
  |pubmedID=2188210
 
  |pubmedID=2188210
 
  |pubmedCID=
 
  |pubmedCID=
−
  |DOI=
+
  |DOI=10.1353/pbm.1990.0008
 
  |date=1990
 
  |date=1990
−
  |accessdate=
+
  |accessdate=2024-12-22
−
}}</ref> The human penis has retained and modified its prepuce over a period of extraordinarily evolution.<ref>{{REFjournal
+
}}</ref> The human [[penis]] has retained and modified its prepuce over an extraordinary period of evolution.<ref>{{REFjournal
 
  |last=Dixson
 
  |last=Dixson
−
  |first=A.F.
+
  |init=AF
 
  |title=Baculum length and copulatory behavior in primates
 
  |title=Baculum length and copulatory behavior in primates
 
  |journal=American Journal of Primatology
 
  |journal=American Journal of Primatology
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  |issue=1
 
  |issue=1
 
  |pages=51-60
 
  |pages=51-60
−
  |url=
+
  |url=https://onlinelibrary.wiley.com/doi/10.1002/ajp.1350130107
 
  |quote=
 
  |quote=
−
  |pubmedID=
+
  |pubmedID=2188210
 
  |pubmedCID=
 
  |pubmedCID=
 
  |DOI=10.1002/ajp.1350130107
 
  |DOI=10.1002/ajp.1350130107
 
  |date=1987
 
  |date=1987
−
  |accessdate=2010-06-22
+
  |accessdate=2024-12-22
 
}}</ref> The rapid divergence in external genital anatomy between humans and ancestral apes is thought to have occurred in the last seven million years.<ref name="cold-mcgrath"/>
 
}}</ref> The rapid divergence in external genital anatomy between humans and ancestral apes is thought to have occurred in the last seven million years.<ref name="cold-mcgrath"/>
  
−
The external genitalia of primates are marked by an astounding variety of specialized structures, but over the past 65 million years, the prepuce has not only withstood the test of time, it has also evolved in its complexity. The survival and further development of the human penile prepuce in the face of the extraordinarily rapid evolution of humans over the last 7 to 9 million years is particularly noteworthy, especially against the background of a fourfold increase in penile size.<ref name="Diamond"/>
+
The external genitalia of primates are marked by an astounding variety of specialized structures, but over the past 65 million years, the [[prepuce]] has not only withstood the test of time, it has also evolved in its complexity. The survival and further development of the human penile prepuce in the face of the extraordinarily rapid evolution of humans over the last 7 to 9 million years is particularly noteworthy, especially against the background of a fourfold increase in penile size.<ref name="Diamond"/>
  
 
=== Comparative anatomy ===
 
=== Comparative anatomy ===
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A histologic study of the penile and clitoral prepuce, carried out on human and non-human primates, showed that corpuscular receptors are concentrated at the prepuce/glans penis and the prepuce/glans clitoridis interface in humans and rhesus monkeys.<ref name="macaca">{{REFjournal
 
A histologic study of the penile and clitoral prepuce, carried out on human and non-human primates, showed that corpuscular receptors are concentrated at the prepuce/glans penis and the prepuce/glans clitoridis interface in humans and rhesus monkeys.<ref name="macaca">{{REFjournal
 
  |last=Cold
 
  |last=Cold
−
  |first=C.
+
  |init=CJ
 +
|author-link=Christopher J. Cold
 
  |last2=Tarara
 
  |last2=Tarara
−
  |first2=R.
+
  |init2=R
 
  |title=Penile and clitoral prepuce mucocutaneous receptors in macaca mulatta
 
  |title=Penile and clitoral prepuce mucocutaneous receptors in macaca mulatta
 
  |journal=Vet Pathol
 
  |journal=Vet Pathol
Line 195: Line 241:
 
  |DOI=
 
  |DOI=
 
  |date=1997
 
  |date=1997
−
  |accessdate=
+
  |accessdate=2023-12-19
 
}}</ref> Surprisingly different patterns of innervation, however, are seen between human and non-human male primates.<ref name="cold-mcgrath"/>
 
}}</ref> Surprisingly different patterns of innervation, however, are seen between human and non-human male primates.<ref name="cold-mcgrath"/>
  
 
[[Image:Rhesus-Monkey-&-Human-Penis.gif]]
 
[[Image:Rhesus-Monkey-&-Human-Penis.gif]]
  
−
The rhesus monkey has fewer corpuscular receptors in the prepuce (foreskin) and more corpuscular receptors in the glans (head). In humans, however, the glans penis has few corpuscular receptors and predominant free nerve endings,<ref>Halata, Z, & Spaethe, A. (1997). Sensory innervation of the human penis. Plenum Press.</ref><ref name="halta86">Halata, Z, & Munger, B. (1986). The neuroanatomical basis for the protopathic sensibility of the human glans penis. Brain Res, 34(506)</ref> consistent with protopathic sensibility. Protopathic simply refers to a low order of sensibility (consciousness of sensation), such as to deep pressure and pain, that is poorly localised. The human glans penis has virtually no fine touch sensation and can only sense deep pressure and pain at a high threshold.<ref>Von, F.M. (1894). Beiträge zur Physiologie des Schmerzsinns. Akad Wiss Leipzig Math.-Naturwiss Kl Ber.</ref><ref name="macaca"/> While the human glans penis is protopathic, the prepuce contains a high concentration of touch receptors in the [[Ridged band|ridged band]].<ref name="cold-mcgrath"/>
+
The rhesus monkey has fewer corpuscular receptors in the prepuce (foreskin) and more corpuscular receptors in the glans (head). In humans, however, the [[glans penis]] has few corpuscular receptors and predominant free nerve endings,<ref name="halata1997">{{REFjournal
 +
|last=Halata
 +
|first=
 +
|init=Z
 +
|author-link=
 +
|last2=Spaethe
 +
|first2=
 +
|init2=A
 +
|author2-link=
 +
|etal=no
 +
|title=Sensory Innervation of the Human Penis
 +
|trans-title=
 +
|language=
 +
|journal=Adv Exp Med Biol
 +
|location=
 +
|date=1997
 +
|season=
 +
|volume=424
 +
|issue=
 +
|article=
 +
|page=
 +
|pages=
 +
|url=https://cirp.org/library/anatomy/halata2/
 +
|archived=
 +
|quote=
 +
|pubmedID=9361804
 +
|pubmedCID=
 +
|DOI=10.1007/978-1-4615-5913-9_48
 +
|accessdate=2024-12-22
 +
}}</ref>
  
−
In the human penis, the prepuce is known to have ten times more corpuscular sensory receptors than the glans penis.<ref name="halta86"/>
+
In the human [[penis]], the [[prepuce]] is known to have ten times more corpuscular sensory receptors than the [[glans penis]].<ref name="halata1986">{{REFjournal
 +
|last=Halata
 +
|first=
 +
|init=Z
 +
|author-link=
 +
|last2=Munger
 +
|first2=
 +
|init2=BL
 +
|author2-link=
 +
|etal=no
 +
|title=The neuroanatomical basis for the protopathic sensibility of the human glans penis
 +
|trans-title=
 +
|language=
 +
|journal=Brain Res
 +
|date=1986-04-23
 +
|volume=371
 +
|issue=2
 +
|pages=205-30
 +
|url=
 +
|archived=
 +
|quote=
 +
|pubmedID=3697758
 +
|pubmedCID=
 +
|DOI=10.1016/0006-8993(86)90357-4
 +
|accessdate=2024-12-22
 +
}}</ref>
  
−
The male and female prepuce has persisted in all primates, which strongly supports the contention that the prepuce is valuable genital sensory tissue. The corpora cavernosa and the prepuce are the only two universally common characteristics of the primate penis.<ref name="cold-mcgrath"/>
+
The male and female prepuce has persisted in all primates, which strongly supports the contention that the [[prepuce]] is valuable genital sensory tissue. The corpora cavernosa and the prepuce are the only two universally common characteristics of the primate penis.<ref name="cold-mcgrath"/><ref name="macaca"/> While the human [[glans penis]] is protopathic, the [[prepuce]] contains a high concentration of touch receptors in the [[Ridged band|ridged band]].<ref name="cold-mcgrath"/>
  
−
{{SEEALSO}}
+
== Further reading ==
−
* [[Foreskin sensitivity]]
 
−
 
 
−
=== Further reading ===
 
 
* {{REFbook
 
* {{REFbook
 
  |last=Denniston
 
  |last=Denniston
−
  |first=GC
+
  |init=GC
 
  |author-link=George C. Denniston
 
  |author-link=George C. Denniston
 
  |last2=Hodges
 
  |last2=Hodges
−
  |first2=FM
+
  |init2=FM
 
  |author2-link=Frederick M. Hodges
 
  |author2-link=Frederick M. Hodges
 
  |year=1999
 
  |year=1999
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* {{REFbook
 
* {{REFbook
 
  |last=Martin
 
  |last=Martin
−
  |first=RD
+
  |init=RD
 
  |year=1990
 
  |year=1990
 
  |title=Primate origins and evolution: a phylogenetic reconstruction
 
  |title=Primate origins and evolution: a phylogenetic reconstruction
Line 246: Line 343:
 
  |pages=
 
  |pages=
 
  |location=New Jersey
 
  |location=New Jersey
−
  |publisher=Princeton University Press
+
  |publisher={{UNI|Princeton University|PU}} Press
 
  |isbn=
 
  |isbn=
 
  |quote=
 
  |quote=
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* {{REFbook
 
* {{REFbook
 
  |last=Butler
 
  |last=Butler
−
  |first=AB
+
  |init=AB
 
  |last2=Hodos
 
  |last2=Hodos
−
  |first2=W
+
  |init2=W
 
  |year=1996
 
  |year=1996
 
  |title=Comparative vertebrate neuroanatomy: evolution and adaptation
 
  |title=Comparative vertebrate neuroanatomy: evolution and adaptation
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}}
 
}}
  
−
[[Image:The-Descent-of-Man-and-Selection-in-Relation-to-sex.gif|100x130px]]
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[[Image:The-Descent-of-Man-and-Selection-in-Relation-to-sex.gif|200x260px]]
−
[[Image:Primate_Origins_and_Evolution.gif‎|100x130px]]
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[[Image:Primate_Origins_and_Evolution.gif‎|200x260px]]
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[[Image:Perspectives_in_biology_and_medicine.gif‎|100x130px]]
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[[Image:Perspectives_in_biology_and_medicine.gif‎|200x260px]]
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[[Image:America_Journal_of_Primatology.gif‎|100x130px]]
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[[Image:America_Journal_of_Primatology.gif‎|200x260px]]
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[[Image:Studies_In_Neurology.gif‎|100x130px]]
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[[Image:Studies_In_Neurology.gif‎|200x260px]]
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[[Image:Why_Sex_Is_Fun.gif‎|100x130px]]
+
[[Image:Why_Sex_Is_Fun.gif‎|200x260px]]
−
[[Image:Mothering.gif‎|100x130px]]
+
[[Image:Mothering.gif‎|200x260px]]
  
−
=== Videos ===
+
== Videos ==
 +
=== Functions of The Foreskin - Part 1 ===
 
<youtube>http://www.youtube.com/watch?v=r9DoCn3gATE</youtube>
 
<youtube>http://www.youtube.com/watch?v=r9DoCn3gATE</youtube>
−
'''Functions of The Foreskin - Part 1'''
 
  
 +
=== Functions of The Foreskin - Part 2 ===
 
<youtube>http://www.youtube.com/watch?v=Ps1dkbcOKfA</youtube>
 
<youtube>http://www.youtube.com/watch?v=Ps1dkbcOKfA</youtube>
−
'''Functions of The Foreskin - Part 2'''
+
 
 +
{{SEEALSO}}
 +
* [[Foreskin sensitivity]]
 +
* [[Penis]]
 +
 
 +
{{LINKS}}
 +
* {{REFweb
 +
|url=http://www.intactaus.org/information/functionsoftheforeskin/
 +
|title=Functions of the Foreskin
 +
|last=Helard
 +
|first=Lou
 +
|author-link=
 +
|publisher=Intact Australia
 +
|website=
 +
|date=2014-08-01
 +
|accessdate=2020-05-29
 +
|format=
 +
|quote=
 +
}}
  
 
{{REF}}
 
{{REF}}
  
 +
[[Category:Male sexuality]]
 
[[Category:Physiology]]
 
[[Category:Physiology]]
  
 
[[Category:From Intactipedia]]
 
[[Category:From Intactipedia]]
 
[[Category:From IntactWiki]]
 
[[Category:From IntactWiki]]
 +
 +
[[de:Entwicklung der Vorhaut]]

Latest revision as of 22:29, 9 April 2025

Charles Darwin.

Millions of years of evolution have fashioned the human body into a model of refinement, elegance, and efficiency, with every part having a function and purpose. Evolution has determined that mammals' genitals should be sheathed in a protective, responsive, multipurpose foreskin. Every normal human being is born with a foreskin. In females, it protects the glans of the clitoris; in males, it protects the glans of the penis. Thus, the foreskin is an essential part of human sexual anatomy.[1]

Over the last 65 million years, the prepuce has offered reproductive advantages. Although advocates of mass circumcision hypothesize that the prepuce represents a design flaw, it is more likely that sexual selection has refined the external genitalia of each primate species for reproductive excellence.[2]

The reproductive advantages provided by the prepuce during the last 65 million years should not be taken lightly. The human prepuce is not "vestigial" but is, in fact, an evolutionary advancement over the prepuce of other primates.[2]

Evolution

Natural selection

Charles Darwin (1859) has done an admirable work in introducing the principle of natural selection to explain evolution.[3]

Morphology

The prepuce has been well conserved by evolution.[2] In primates, the foreskin has been present in the genitalia of both sexes of mammals for at least 65 million years and likely has been present for over 100 millions years of evolution, based on its commonality as an anatomical feature in mammals.[4] The evolution of complex penile morphologies like the foreskin may have been influenced by females.[5][6][7] It has been proposed that the foreskin evolved to facilitate masturbation,[8] but, in accordance with Darwin's principles of survival, it is more likely that the gliding action of the male prepuce facilitates penetration and fertilization of the female.[9] The human prepuce has an increase in corpuscular innervation and concomitant decrease in corpuscular receptors in the human glans compared to the prepuce and glans of lower primates, demonstrating an evolutionary advancement.[10][11] The human penis has retained and modified its prepuce over an extraordinary period of evolution.[12] The rapid divergence in external genital anatomy between humans and ancestral apes is thought to have occurred in the last seven million years.[2]

The external genitalia of primates are marked by an astounding variety of specialized structures, but over the past 65 million years, the prepuce has not only withstood the test of time, it has also evolved in its complexity. The survival and further development of the human penile prepuce in the face of the extraordinarily rapid evolution of humans over the last 7 to 9 million years is particularly noteworthy, especially against the background of a fourfold increase in penile size.[5]

Comparative anatomy

A histologic study of the penile and clitoral prepuce, carried out on human and non-human primates, showed that corpuscular receptors are concentrated at the prepuce/glans penis and the prepuce/glans clitoridis interface in humans and rhesus monkeys.[13] Surprisingly different patterns of innervation, however, are seen between human and non-human male primates.[2]

Rhesus-Monkey-&-Human-Penis.gif

The rhesus monkey has fewer corpuscular receptors in the prepuce (foreskin) and more corpuscular receptors in the glans (head). In humans, however, the glans penis has few corpuscular receptors and predominant free nerve endings,[14]

In the human penis, the prepuce is known to have ten times more corpuscular sensory receptors than the glans penis.[15]

The male and female prepuce has persisted in all primates, which strongly supports the contention that the prepuce is valuable genital sensory tissue. The corpora cavernosa and the prepuce are the only two universally common characteristics of the primate penis.[2][13] While the human glans penis is protopathic, the prepuce contains a high concentration of touch receptors in the ridged band.[2]

Further reading

  • REFbook Denniston GC, Hodges FM (1999): Anatomy and histology of the penile and clitoral prepuce in primates. Kluwer Academic/Plenum Publishers.
  • REFbook Martin RD (1990): Primate origins and evolution: a phylogenetic reconstruction. New Jersey: Princeton University Press.
  • REFbook Butler AB, Hodos W (1996): Comparative vertebrate neuroanatomy: evolution and adaptation. New York: Wiley-Liss.

The-Descent-of-Man-and-Selection-in-Relation-to-sex.gif Primate Origins and Evolution.gif Perspectives in biology and medicine.gif America Journal of Primatology.gif Studies In Neurology.gif Why Sex Is Fun.gif Mothering.gif

Videos

Functions of The Foreskin - Part 1

Functions of The Foreskin - Part 2

See also

External links

References

  1. Jump up ↑ REFjournal Fleiss PM. The Case Against Circumcision. Mothering: The Magazine of Natural Family Living. 1997 (Winter); : 36-45. Retrieved 22 December 2024.
  2. ↑ Jump up to: a b c d e f g REFbook Cold CJ, McGrath K (1999): Anatomy and histology of the penile and clitoral prepuce in primates, in: Male and female circumcision: medical, legal, and ethical considerations in pediatric practice. New York ISBN 0306461315.
  3. Jump up ↑ REFbook Darwin, Charles (1859): Chapter Four: Natural Selection, in: The Origin of Species. London: John Murray. Retrieved 18 December 2024.
  4. Jump up ↑ REFbook Martin RD (1990): Primate Origins and Evolution: A Phylogenetic Reconstruction. New Jersey: Princeton University Press. ISBN 978-0-691-08565-4.
  5. ↑ Jump up to: a b REFbook Diamond JM (1997): Why Sex is Fun: The Evolution of Human Sexuality. London: Weidenfeld & Nicolson. ISBN 0465031269.
  6. Jump up ↑ REFbook Darwin C (1871): The Descent of Man and Selection in Relation to Sex. London: Murray. ISBN 1148750932. Retrieved 22 December 2024.
  7. Jump up ↑ REFbook Short RV (1981): Sexual selection in man and the great apes, in: Reproductive Biology of the Great Apes: Comparative and Biomedical Perspectives. Graham CE (ed.). New York: Academic Press.
  8. Jump up ↑ REFjournal Cox G. De virginibus puerisque: The function of the human foreskin considered from an evolutionary perspective. Med Hypotheses. 1995; 45(6): 617-621. PMID. DOI. Retrieved 22 December 2024.
  9. Jump up ↑ REFjournal Taves DR. The intromission function of the foreskin. Medical Hypotheses. August 2002; 59(2): 180-2. PMID. DOI. Retrieved 22 December 2024.
  10. Jump up ↑ REFjournal Nadler RD. Proximate and ultimate influences on the regulation of mating in the great apes. American Journal of Primatology. 1995; 37(2): 93-102. PMID. DOI. Retrieved 22 December 2024.
  11. Jump up ↑ REFjournal Williams-Ashman HG. Enigmatic features of penile development and functions. Perspectives in Biology and Medicine. 1990; 33: 335-374. PMID. DOI. Retrieved 22 December 2024.
  12. Jump up ↑ REFjournal Dixson AF. Baculum length and copulatory behavior in primates. American Journal of Primatology. 1987; 13(1): 51-60. PMID. DOI. Retrieved 22 December 2024.
  13. ↑ Jump up to: a b REFjournal Cold CJ, Tarara R. Penile and clitoral prepuce mucocutaneous receptors in macaca mulatta. Vet Pathol. 1997; 34(506) Retrieved 19 December 2023.
  14. Jump up ↑ REFjournal Halata Z, Spaethe A. Sensory Innervation of the Human Penis. Adv Exp Med Biol. 1997; 424 PMID. DOI. Retrieved 22 December 2024.
  15. Jump up ↑ REFjournal Halata Z, Munger BL. The neuroanatomical basis for the protopathic sensibility of the human glans penis. Brain Res. 23 April 1986; 371(2): 205-30. PMID. DOI. Retrieved 22 December 2024.
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