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Function of the human hymen
Abstract
The few existing hypotheses for the function of the human hymen are weak. These are briefly reviewed, and a new hypothesis is proposed. We suggest that the appearance of the juvenile human hymen is based on 'premature' birth, following which infant helplessness and a subsequent advantage for vaginal protection from external sources of infection allowed natural selection to increase its persistence well into juvenile life.
... Medical opinions about the existence of a membrane seem to be inconsistent and lacking in scientific proof. The location of the hymen and its eventual function are often the topic of discussions (Hobday et al, 1997;Maul, 2007). O 'Connell et al (2008'Connell et al ( : 1885 claimed that the hymen is a 'circumferential skin structure composed of non hair-bearing skin' that varies greatly in terms of size, shape, form and presence. ...
... The most widely misunderstood belief in this study is that there is a breakable membrane covering the vagina. This is also the dominating perception brought forth in medical literature (Hobday et al, 1997;Standring, 2005;Maul, 2007;O'Connell et al, 2008). Despite the majority of respondents in this study being women, who could easily have discovered that there is no covering membrane by examining their own bodieswhen they were younger, few of the respondents stated this. ...
... A ranking criterion was the position and independent status of women in the society, which may well make the question of having or not having a hymen seem unimportant. A study carried out by Hobday et al (1997) concluded that in societies where virginity is valuable, more women are likely to have a hymen. This clearly points to the negative influence of patriarchal structures being prominent in some contexts globally. ...
Ideas and misconceptions about the vaginal opening, hymen and virginity are widely held in many societies. The aim of this study was to investigate the perceptions of the vaginal opening, the hymen and its connection with bleeding, sexual intercourse, physical activity and virginity verification among an international group of midwives. an online questionnaire about the topic was emailed to midwives who attended the International confederation of Midwives' (ICM) congress in Glasgow. The respondents (n=480) represented five continents with european delegates dominating the attendees. Two thirds (66%) of the respondents believed that girls are born with a covering membrane that breaks during the first vaginal intercourse and 52% thought that the membrane breaks during physical activities. Fifteen percent connected bleeding with the first vaginal intercourse and 21% stated that virginity can be verified by a gynecological examination. Midwives play a significant role in improving the sexual and reproductive health of women, thus in order to challenge long-held biomedical ‘truths’, midwives must become conscious and knowledgeable about how the myths surrounding the hymen contribute to gender inequalities and health disparities in women. a first step is to implement gender perspectives in midwifery education.
... In many patriarchal cultures, the sexual history of girls and women is used as a significant determinant of their societal, community, family, and individual status [1,2]. Frequently, conclusions about sexual history are made based on assumptions about the hymen, a small membranous tissue with no known biological function [3,4], which typically occupies a portion of the external vaginal opening in females. ...
... Large, cross-cultural, population-based studies that address the absence or presence of a hymen at birth have not been published. None of the existing studies provide or identify a clear function for the hymen [3,4]. ...
Conclusions about women’s and girls’ sexual history are made in some settings based on assumptions about the hymen, a small membranous tissue with no known biological function, which typically occupies a portion of the external vaginal opening in females. Clinicians, however, continue to refer to changes in the hymen to assess for a history of consensual or nonconsensual sexual intercourse. We reviewed published evidence to dispel commonly held myths about the hymen and its morphology, function, and use as evidence in cases of sexual violence.
An examination of the hymen is not an accurate or reliable test of a previous history of sexual activity, including sexual assault. Clinicians tasked with performing forensic sexual assault examinations should avoid descriptions such as “intact hymen” or “broken hymen” in all cases, and describe specific findings using international standards and terminology of morphological features.
We call on clinicians to consider the low predictive value of a hymen examination and to: 1) avoid relying solely on the status of the hymen in sexual assault examinations and reporting; 2) help raise awareness of this issue among their peers and counterparts in law enforcement and the judicial system; and 3) promote fact-based discussions about the limitations of hymenal examinations as part of clinical education for all specialties that address the sexual or reproductive health of women and girls.
... These findings are consistent with a similar study of European midwives that found the most prevalent misconceptions were about the hymen (Christianson & Eriksson, 2013). In addition to social and cultural narratives about the hymen, the medical literature has also supported the idea of an "intact hymen" (Bauman, 2012;Huang et al., 2019) that it is broken during penetration (Hobday et al., 1997;Maul, 2007), as well as the idea of "virginity sparing" medical procedures (Egbe et al., 2019;Ludwin et al., 2018). ...
Although virginity is not a medical term and is instead socially constructed, it remains unknown what medical providers believe about the biological basis of virginity. This study explored providers’ and medical students’ beliefs about virginity and the potential impact of such beliefs on healthcare. This was a concurrent mixed-method survey study of 124 medical students and 216 healthcare providers (Registered Nurse, Physician Assistant, Nurse Practitioner, and Doctor of Medicine) at Penn State Health and The Pennsylvania State University College of Medicine. Participants rated their level of agreement with common misconceptions about virginity on a six-point Likert scale. Open-ended questions gave respondents the opportunity to define virginity and to describe terms like virgin and virginal in the context of sexual experience and the medical lexicon. We identified common themes in the qualitative data using thematic analysis. Frequencies of misconceptions and statistically significant demographic associations were identified in the quantitative data. Definitions of virginity were varied and vague, most with negative connotations. A majority of respondents said that virginity has no biological basis. Many participants identified downsides to use of terms like virgin, virginity, and virginal in medicine. The most prevalent misconceptions about virginity were related to the hymen. Seventeen percent of students and 26% of providers at least somewhat agreed that it was possible to determine whether a person has engaged in vaginal intercourse through a gynecological exam. Misconceptions about virginity persist in medicine and bias, even if unintended, may impact the quality-of-care people with vaginas receive. Language around sexual health should be specific, inclusive, clinically relevant, and free from judgment. Medical education must continue to work to eliminate the concept of a biological basis to virginity.
... Una hipótesis más plausible es la señalada por Hobday et al. (1997) quienes sugieren que la presencia del himen humano juvenil se basa en un nacimiento "prematuro", luego de lo cual la indefensión infantil y una subsiguiente ventaja para la protección vaginal de fuentes externas de infección permitieron que la selección natural aumentara su persistencia hasta bien entrada la vida juvenil. ...
In Terminologia Anatomica the term hymen is identified with the number 3530. It is a small membranous tissue that normally occupies a part of the external vaginal opening in women. The relevance of the term hymen has been scarcely addressed in the literature of the anatomical terminology field. Therefore, the objective of this work was to analyze this term, verify its etymology and functionality, and determine how it has been considered in certain cultural clinical and legal aspects. The term hymen comes from the Latin hymen, borrowed from the Greek hymḗn ὑμήν , which means membrane. With the general value of any membrane, it was used in Greece from the 5th century BC, however, through a phenomenon of Latin specialization, from the 1st and 2nd centuries AD, the term was used applying its current meaning. Its origin comes from the name of the Greek god of marriage called Hymenaeus, which links the term to an eponym and a myth at the same time. Despite the above, we believe that its conservation in Terminologia Anatomica could be due to its long history, even though there may be better options to name this structure. The hymen does not have a known biological function, however, it has been highly valued at a cultural, clinical and legal level, in which the physical examination has determined conclusions about the sexual history of women and girls even when the evidence shows that it is not an accurate or reliable proof of sexual activity.
... Further characterisation of the equine hymen between birth and the 2-year-old stage would be of significant interest. The hymen is often referred to as a remnant of no functional significance, however, it is possible that the hymen has evolved to protect the cranial reproductive tract from contamination especially when the genital organs are immature (Hobday et al. 1997). Female reproductive tract abnormalities Caudal reproductive tract deformities involving the vagina and hymen are examples of where only theories exist as to their pathophysiology. ...
Introduction
The report by McCarthy and coworkers (McCarthy et al. 2021) in this issue describes a case of vaginal septum with pyometra in a 10‐week‐old Westphalian filly foal. This is an interesting case report which evokes thought about the developmental abnormalities of the caudal female reproductive and urogenital tracts and their pathophysiology. Such anomalies are rare, reflected by the limited number of cases reported in the literature involving mares/fillies with uterine, cervical, vaginal and hymenal abnormalities.
... Its name derived from the ancient Greek god of marriage, Hymenaeus, the hymen is a mucous membrane that partly or completely covers the external orifice of the vagina (Hendricks and Oliver 1999). Although it lacks any known physiological function in the female human body (Sloane 2002;Hobday et al. 1997;Williams and Warwick 1980), it is an important physical artifact in a variety of cultural contexts in which the loss of female virginity is believed to be congruous with a ruptured hymen and subsequent bleeding. However, the medicalization of virginity is problematic for a number of reasons. ...
From Viagra to in vitro fertilization, new technologies are rapidly changing the global face of reproductive health. They are far from neutral: religious, cultural, social, and legal contexts condition their global transfer. The way a society interprets and adopts (or rejects) a new technology reveals a great deal about the relationship between bodies and the body politic. Reproductive health technologies are often particularly controversial because of their potential to reconfigure kinship relationships, sexual mores, gender roles, and the way life is conceptualized. This collection of original ethnographic research spans the region from Morocco and Tunisia to Israel and Iran and covers a wide range of technologies, including emergency contraception, medication abortion, gamete donation, hymenoplasty, erectile dysfunction, and gender transformation.
... Ço cuk luk ça ğın da dış or tam dan ge le bi le cek mik ro or ga niz ma la ra ve ya ban cı ci simle re kar şı do ğal bir ko ru ma ara cı olup pu ber te ile bir lik te va jina flo ra sı nın ol gun laş ma sıy la bu gö revi so na er mek te dir. 11,12 Himen, in san di şi si nin ya şamı bo yun ca ös tro jen ve ay nı za man da pe net ras yon ile de ği şen di na mik bir ya pı dır. 13,14 Ço cu ğun bü yüme si ne pa ra lel ola rak, himen de bü yür. ...
Amaç: Himen, vajina mukozasının devamından ve vajina ağzında bir kıvrıntı meydana getirmesinden oluşmuş mukoza karakterinde bir zardır. Himen muayenesi yapmak için anatomisini iyi bilmek gerekir. Himen tipleri, çeşitli kriterlere göre sınıflandırılmış olsa da, bazen bu kriterlere uymayan çok farklı şekillerde himen yapıları ile karşılaşılabilmektedir. Çalışmada, muayeneleri yapılan sağlam himenler değerlendirilerek, morfolojik özelliklerinin ortaya konulması, muayene esnasında dikkat edilmesi gereken noktaların vurgulanması amaçlanmıştır. Gereç ve Yöntemler: Konya Adli Tıp Şube Müdürlüğü tarafından muayenesi yapılan cinsel saldırı iddiasıyla gönderilen olgular ile ölü muayene ve otopsileri yapılan olgular içerisinden, sağlam himene sahip olduğu belirlenenler retrospektif olarak incelenmiştir. Olgular, demografik özellikleri ve himen morfolojileri yönünden değerlendirilmiştir. Bulgular: 2005-2007 yılları arasında himen muayenesi yapılan 226 olgudan 97 (%42.9)'sinin, ölü muayene ve otopsisi yapılan 156 olgudan (1 yaş ve üzeri) 36 (%23.1)'sının sağlam himene sahip olduğu görüldü. Toplam 133 olgunun yaşları 1 ile 45 arasında değişmekte olup, ortalama yaş 19.4 ± 14.1 bulundu. Himen şekilleri yönünden değerlendirildiğinde; 118 (%88.7)'sinin tipik, 15 (%11.3)'inin atipik formda olduğu izlendi. Himen serbest kenar karakteri yönünden değerlendirildiğinde; 75 (%56.4) himende doğal çentik bulunmazken (düz), 36 (%27.1) himende bir ya da daha fazla küçük doğal çentik mevcuttu. Himenlerin 32 (%24.1)'si duhule müsait idi. Sonuç: Himen muayenesi, özellikle cinsel saldırıya uğradığı iddia edilen olgularda büyük önem taşımaktadır. Ayrıca duhule müsait himenler, yeni evlenen çiftler arasında sorun oluşturmaktadır. Her ne kadar sık görülen himen tipleri değerlendirilirken fazla zorluk çekilmese de, atipik ve nadir görülen himen formları, muayeneyi yapan hekimleri yanıltabilmektedir. Bu gibi durumlarda hekim, mümkünse himen muayenesi konusunda tecrübeli bir başka hekime de danışarak en doğru sonuca ulaşmaya çalışmalıdır.
Objective: Hymen is a mucous membrane that forms as a continuation and a twisting at the opening of vagina of vaginal mucous membrane. It is necessary to know its anatomy to examine the hymen. Although hymen types have been classified according to the various criteria, sometimes it is possible to find very different types of hymens that do not fit those classifications. In this study, it is aimed to demonstrate morphological features of the hymens, to emphasize the points which will be minded during examination, by evaluating the examined undeflorated hymens. Material and Methods: The cases who had undeflorated hymens were retrospectively examined within the cases examined at the Konya Branch of Forensic Medicine Council with the claim of sexual assault and the death cases whose external examination and autopsies were performed. The cases were evaluated according to their demographic aspects and hymen morphologies. Results: It was determined that, between 2005 and 2007, of the 226 cases whose hymen examinations were performed, 97 (42.9%) and of the 156 cases (1 year old and older) whose external examination and autopsies performed, 36 (23.1%) cases had undeflorated hymens. The ages of total 133 cases changed between 1 and 45 with the average of 19.4 ± 14.1 years. When the types of hymen were considered, 118 (88.7%) of them had typical, 15 (11.3%) of them had atypical hymens. When the hymen was evaluated according to free edge characteristics, there were not any notches in 75 (56.4%) hymens (smooth) and in 36 (27.1%) hymens there were one or more than one small notches. 32 (24.1%) of the cases were anatomical virgin. Conclusion: The hymen examination is critically important in the cases where the victims were claimed to be under sexual assault. Furthermore, anatomical virgin hymens may cause problems between new married couples. Although there is not much difficulty in evaluating commonly seen hymen types, atypical and rare hymen forms can mislead the physicians who perform the examination. In such cases, the physician should ask for advice from an experienced physician on hymen examination to reach to the rightest decision.
... It may be a barrier to infections during prepubertal period. Actually, desire for virginity is seen in Islamic and many non-Islamic cultures [10][11][12][13][14][15]. ...
Imperforate hymen is a rare condition but it is the most frequent obstructive anomaly of the female lower genital
tract. In most cases the diagnosis is missed in childhood and is made after puberty when the patient presents
with haematocolpos and heamatometra . The patient presented with uncommon symptoms of urinary retention
apart from delayed menarche and pain . Here we present a 14 year old girl who presented with lower
abdominal pain and acute urinary retention. She was diagnosed clinically and by ultrasound as imperforate
hymen with hematocolpus . She was treated by a virginity preserving hymenotomy. This case is presented to
address clinicians the possibility of imperforate hymen as a differential diagnosis in acute urinary retention.
Keywords: Imperforate hymen, urinary retention, haematocolpos, ultrasonography
... 8 Humans are unique members of the primate group, possessing sexual characteristics different from other hominoids (apes). 9 According to many sources, human female is the only primate member to possess a hymen. 10,11 However, Balke et al reported the presence of membranous constriction (hymen) with an orifice, less than 2 cm in diameter in nulliparous elephants, that is not broken by mating, but only during birth. ...
Background: In conservative cultures, the presence of hymen without rupture in a virgin girl represents an indication of female pride and honor. Accordingly, there are many crimes, committed due to wrong views and conceptions among young people in such societies. The current review aimed to highlight the anatomy of the hymen, in a trial to create a better understanding and to eliminate misconceptions about virginity.
Methods: Databases of PubMed, ScienceDirect, SpringerLink, Wiley Interscience and others were searched. The research papers are studied and discussed.
Results: The hymen is a thin mucous membrane, partially closing the vaginal orifice. It represents an embryological remnant, originating from the urogenital sinus. It varies greatly in shape. Its elasticity increases after puberty so that it may allow penile penetration without rupture and bleeding.
Conclusions: Hymen is not an accurate indication of virginity. Knowledge of the hymen anatomy and its abnormalities is essential to eliminate the misconceptions about it.
... Embryologically, it is a membranous remnant at the junction of sino-vaginal bulb and mullerian ducts. Although originally it was considered as a vestigial structure, its evolutionary role in protecting female infants from pelvic infections has recently been postulated [1]. Until now, surgery of hymen is largely limited to 'hymenotomy' when it is congenitally imperforated. ...
Curiosity provoked by the hymen among laity and learned, is disproportionate to its dimensions. Embryologically, it is a membranous remnant at the junction of sino-vaginal bulb and mullerian ducts. Although originally it was considered as a vestigial structure, its evolutionary role in protecting female infants from pelvic infections has recently been pos-tulated [1]. Until now, surgery of hymen is largely limited to ‘hymenotomy’ when it is congenitally imperforated. In this issue of Indian Journal of Surgery (2009; 71:221–223) Vishwa Prakash has described his technique of hymeno-plasty (more correctly hymenorrhaphy). This unusual paper provokes several scientifi c, ethical and social concerns. First of all, why would somebody seek reconstruction of torn hymen? Intact hymen is long held as a sign of virginity. Blood stained bed-sheets are expected on nuptial nights and they are vividly portrayed in popular cinema to represent bleeding from ruptured hymen on defl oration. Deviation from this hegemonic, religious expectation has harmful repercussion on the woman which ranges from shame to ‘honour killing’ [2]. This misconception must have origi-nated probably because of phonetic resemblance between the two Greek words “Hymen” and “Hymn”. The word “hymen” means “membrane” as evident from terms such as “hymenology” (anatomical study of membranes), “hyme-nopterons” (insects with membranous wings) and “hyme-nolepis” (tapeworms with membrane suckers). According to some etymologists, even the word “human” originated from the root word “hymen” because human fetus is cov-ered with amniotic membrane during gestation. Appropri-ately, membranous remnant of vagina is termed as “
... Actually, desire for virginity is also seen in many non-Islamic cultures. 14,15 In western countries, as a part of practices of culturally sensitive health care or personalized treatment alternatives involving cosmetic and personal demands, conservative management might be an alternative surgical option for all patients. 15 In conclusion, conservative surgery with a simple incision and suturing might be an alternative option to standard treatment for IH diagnosed in pubertal period. ...
Background: Imperforate hymen, with an incidence between 0.1% and 0.05%, is the most common obstructive congenital abnormality of the female genital tract. 'Standard' surgical treatment of imperforate hymen involves hymenectomy after a cruciate, plus, or X-shaped hymenotomy incision. Cases: Two cases with imperforate hymen treated with a simple vertical incision are presented. A few oblique su-tures were used to prevent refusion. Postoperative follow up was uneventful. Summary and Conclusion: The importance of the integrity of hymen changes in different cultures and religious groups. Option of a hymen sparing procedure is readily preferred by most of these patients and families. Also preservation of hymenal tissue, hence the perception of 'integrity' of female genitalia, might be an alternative treatment option.
... Actually, desire for virginity is also seen in many non-Islamic cultures. 14,15 In western countries, as a part of practices of culturally sensitive health care or personalized treatment alternatives involving cosmetic and personal demands, conservative management might be an alternative surgical option for all patients. 15 In conclusion, conservative surgery with a simple incision and suturing might be an alternative option to standard treatment for IH diagnosed in pubertal period. ...
Imperforate hymen, with an incidence between 0.1% and 0.05%, is the most common obstructive congenital abnormality of the female genital tract. 'Standard' surgical treatment of imperforate hymen involves hymenectomy after a cruciate, plus, or X-shaped hymenotomy incision.
Two cases with imperforate hymen treated with a simple vertical incision are presented. A few oblique sutures were used to prevent refusion. Postoperative follow up was uneventful.
The importance of the integrity of hymen changes in different cultures and religious groups. Option of a hymen sparing procedure is readily preferred by most of these patients and families. Also preservation of hymenal tissue, hence the perception of 'integrity' of female genitalia, might be an alternative treatment option.
Dieser Beitrag untersucht in intersektionaler Weise benannte und unbenannte soziale Differenzkategorien in Aufklärungsbroschüren über das Hymen. Die zugrunde liegenden Texte sind zwischen 2009 und 2019 in Deutschland und Österreich erschienen und hinterfragen die Beweisbarkeit von Jungfräulichkeit am Körper, um junge Frauen* zu schützen. Neue Benennungen und die Beschreibung als Saum statt als Häutchen sollen dies auch sprachlich verwirklichen und (sexuelle) Selbstbestimmung gegen ein als universal dargestelltes Patriarchat unterstützen. Unberücksichtigt bleiben aber die rassistischen Diskurse, die das Hymen zu einem politischen Thema gemacht haben.
There is a wide range of hymenal variants which exist and usually become apparent to women during puberty. Our case describes a 16-year-old woman with a previously undiagnosed hymenal septum who presented with a retained tampon within the urinary bladder. This case report discusses a rare presentation of a hymenal variant and highlights the importance of understanding the difference in pelvic examinations in children and adolescents when compared with adults and awareness of the different hymenal variants.
Sexual assaults create significant health and legislative problems for every society. All healthcare professionals who have the potential to encounter victims of sexual assault should have some understanding of the acute and chronic health problems that may ensue from an assault. The primary clinical forensic assessment of complainants and suspects of sexual assault should only be conducted by healthcare professionals (doctors, nurses and paramedics) who have acquired specialist knowledge, skills, and attitudes during theoretical and practical training.
This paper provides new perspectives on the scholarship on medicalization and demedicalization, building on an ethnography of hymenoplasty consultations in the Netherlands. By examining how doctors can play an active role in demedicalization, this paper presents novel insights into Dutch physicians' attempt to demedicalize the “broken” hymen. In their consultations, Dutch doctors persuade hymenoplasty patients to abandon the assumed medical definition of the “broken” hymen and offer nonmedical solutions to patients' problems. Drawing from unique ethnographical access from 2012 to 2015 to 70 hymenoplasty consultations in the Netherlands, this paper's original contribution comes from closely examining how demedicalization can be achieved through the process of medicalization. It investigates how Dutch physicians go even further in their efforts to demedicalize by medicalizing “cultural” solutions as an alternative course of action to surgery.
The female vulva is an intricate structure comprising several components. Each structure has been described separately, but the interplay among them and physiologic significance remain controversial. The structures extend inferiorly from the pubic arch and include the mons pubis, labia majora, labia minora, vestibule, and clitoris. The clitoris is widely accepted as the most critical anatomic structure to female sexual arousal and orgasm. The female sexual response cycle is also very complex, requiring emotional and mental stimulation in addition to end organ stimulation.
A vaginal speculum examination of a 17-month-old Holstein heifer with a history of repeated artificial insemination (AI) failures via the cranial vagina revealed the presence of an intact hymen (imperforate hymen) beyond the external urethral orifice, which resembled the vaginal wall. An ultrasonographic examination detected hypoechoic fluid within the vaginal cavity between the intact hymen and the cervix, indicating the presence of hydrocolpos. After sedation and epidural anesthesia, the intact hymen was incised using a scalpel and scissors and removed, while the incised portions were sutured using a simple interrupted method. The heifer became pregnant after three consecutive estruses with the intervals of approximately 20 days and concomitant AIs. The heifer gave birth to a healthy male calf with no complications after a 291-day gestation period. This case reports the presence of an imperforate hymen with hydrocolpos in a Holstein heifer, followed by successful insemination, conception and delivery after removal of the imperforate hymen.
Lesions specific to the posterior fourchette, posterior vestibule (fossa navicularis), and hymen are reviewed. Knowledge of these regional lesions will be helpful if such a patient is encountered.
To review data from patients who have undergone hymenoplasty with a novel surgical technique, termed the STSI (suture three stratums around the introitus) method.
In a retrospective study, data were reviewed from patients who underwent hymenoplasty by STSI at a center in Beijing, China, between January 2010 and January 2014. Patients were scheduled to attend a follow-up appointment 1month after surgery. Long-term follow-up was conducted by telephone. Follow-up data and preoperative and postoperative photos were assessed.
Overall, 125 patients had undergone hymenoplasty using the STSI method. Only 1 (0.8%) patient had an early postoperative complication (uncontrolled bleeding). Among the 99 patients who returned for follow-up at 1month, healing was recorded for 91 (91.9%). Long-term follow-up suggested that no patient had persistent dyspareunia, menstruation changes, or other health problems after the surgery. Among 51 patients who reported sexual intercourse since the surgery, 47 (92.2%) were satisfied with the outcome and 28 (54.9%) reported blood loss during the first intercourse.
The STSI method seems to be an effective, enduring, and safe technique of hymenoplasty.
Copyright © 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.
This book provides an authoritative and comprehensive synthesis of current research on the evolution and physiological control of sexual behaviour in the primates - prosimians, monkeys, apes, and human beings. This new edition has been fully updated and greatly expanded throughout to incorporate a decade of new research findings. It maintains the depth and scientific rigour of the first edition, and includes a new chapter on human sexuality, written from a comparative perspective.
Infections of the urinary and reproductive tracts continue to afflict hundreds of millions of women and girls each year. For those fortunate enough to have access to medical care, the diagnostic and treatment measures used on them have changed little in 40 years and remain far from adequate. The development of alternatives, such as probiotics, has been hindered by lack of funding, but now face bureaucratic barriers that reflect an outdated regulatory system more concerned with policies than care for the patient. The technological advances emerging from human microbiome studies are making it possible to generate a completely new understanding of how microbes interact with the host, what influences them, and when the result is an aberration requiring intervention. But until bridges are built between scientific progress and practice, it is women and girls who will continue to receive suboptimal care for their often persistent and debilitating conditions.
Palaeontologists, Stephen J. Gould and Elisabeth Vrba, introduced the term "ex-aptation" with the aim of improving and enlarging the scientific language available to researchers studying the evolution of any useful character, instead of calling it an "adaptation" by default, coming up with what Gould named an "extended taxonomy of fitness". With the extension to functional co-optations from non-adaptive structures ("spandrels"), the notion of exaptation expanded and revised the neo-Darwinian concept of "pre-adaptation" (which was misleading, for Gould and Vrba, suggesting foreordination). Exaptation is neither a "saltationist" nor an "anti-Darwinian" concept and, since 1982, has been adopted by many researchers in evolutionary and molecular biology, and particularly in human evolution. Exaptation has also been contested. Objections include the "non-operationality objection".We analyze the possible operationalization of this concept in two recent studies, and identify six directions of empirical research, which are necessary to test "adaptive vs. exaptive" evolutionary hypotheses. We then comment on a comprehensive survey of literature (available online), and on the basis of this we make a quantitative and qualitative evaluation of the adoption of the term among scientists who study human evolution. We discuss the epistemic conditions that may have influenced the adoption and appropriate use of exaptation, and comment on the benefits of an "extended taxonomy of fitness" in present and future studies concerning human evolution.
This study investigated, from a gender perspective, perceptions concerning the word "hymen" among students in a Swedish senior high school.
Students answered an open-ended question: What do you think about when you hear the word hymen? The answers were analyzed by using content analysis.
In total, 198 students, aged 17 to 18 years, answered the question. The theme "a fragile biological structure in the female body" described how the vast majority of the girls and 57% of the boys associated the hymen with a thin membrane that breaks during first vaginal intercourse. The theme "a symbol and manifestation of feminine virginity" described the symbolic meanings of having or not having a hymen. The theme "questioning the existence of the hymen" revealed the doubts that some had about its existence.
Most of the students associated the hymen with a breakable membrane. This is problematic. It may lead to misunderstandings about virginity or about bleeding during sexual intercourse. Changing these views about the hymen is important to correct such misunderstanding but may be a significant challenge. In modern medical discourse, in health care, and in popular speech, there are few discussions about the hymen as a social construct, indicating that more gender research concerning hymen-related issues is needed.
Ancient texts and archaeological artifacts provide the starting point for a review of the surgical aspects of female genital mutilation (FGM) in ancient Egypt. Analysis of the ancient surgical procedure incorporates modern experience on the subject as well as ancient literary and cultural perspectives. Comparison of FGM with ancient Egyptian male circumcision and consideration of motivations for the practice contribute to our understanding of FGM. In particular, the documented association between male circumcision and generative ability suggests a novel comparison with a natural process in the female--the breaking of the hymen on first intromission--and ultimately a new hypothesis for the origin of ancient FGM.
The phenomena surrounding the pains commonly related to both first coitus and delivery have been addressed rather poorly in previous work, as regards their evolutionary aspects, during the investigation of human sexuality and reproductive behavior. In particular, the function of the hymen and the significance of defloration are largely misunderstood. The present paper aims to analyse the meaning of these two female physical pains in an evolutionary context. Accordingly, childbirth and defloration pains are hypothesized to manifest an adaptation designed to increase inclusive fitness in human evolutionary history. Clearly, the significance of pain as a message is essentially emotional. Indeed, the intense sexual emotions that may precede and/or follow the pain, the breaking and bleeding of the hymen during the first complete sexual act may generate distinctive strong feelings on/from each side of the newly formed couple. As to labor pain, both the shared intimacy with the mother and the emotional background during confinement may create mutual solicitude among the protagonists (i.e. midwifes, father, mother). Such feelings or attitudes may subsequently turn out to be beneficial to all of them, and more particularly to the newborn. As a general consequence, it appears that the two physical pains under consideration may have behavioral implications, in the sense that they contribute to increasing the stability of the connection between partners and thus, indirectly, to the welfare or even the survival (especially in former times) of the newborn child.
Several hypotheses have been proposed to explain the occurrence of continual sexual receptivity and concealed ovulation in human females. In view of the large number of benefits that would accrue to females if they could sense their own ovulation, these explanations appear insufficient to explain why ovulation is concealed from females as well as from males. The hypothesis presented here is that the phenomenon occurs because of a hominid female tendency to avoid conception in biologically nonadaptive ways. This tendency was countered by natural selection by making ovulation virtually undetectable to women. The sequence of evolutionary adaptations culminating in concealed ovulation is most likely as follows. First, olfactory, visual, and pronounced behavioral cues to ovulation were lost to conspecifics. Coincidentally females evolved continuous receptivity, frequently copulating at times other than when ovulating. Finally, females lost conscious cues to their own fertility. This last step was predicated up...
The existence of differences in pelvic morphology between Plio-Pleistocene hominids and modern humans is well documented (for a recent review see McHenry and Temerin, 1979). Pelvic remodeling during the evolution of the genus Homo has elicited two different interpretations: (1) it has been viewed as a reflection of increased efficiency in bipedalism (McHenry, 1975a; Zihlman, 1978), and (2) it has been interpreted in terms of rapid encephalization that would have generated selection pressure to increase birth canal dimensions (Lovejoy et al., 1973; Lovejoy, 1974, 1975, 1978). When the second hypothesis is scrutinized, the fossil evidence unambiguously indicates that the increase in brain size during human evolution was extraordinary both in magnitude and in rate (Pilbeam and Gould, 1974; Passingham, 1975; Sacher, 1975). This picture of encephalization from H. habilis to H. erectus to H. sapiens is based on estimated cranial capacities of a static series of adults. Obstetrical constraints and thus selection pressures on the pelvis are not, however, dependent on adult cranial dimensions but on those of the fetal cranium at term relative to birth canal dimensions. Moreover, evidence of differences between primate species in the growth rate of the brain and/or in the length of development during ontogeny (Schultz, 1941, 1956; Sacher and Staffeldt, 1974; Passingham, 1975) suggests that encephalization of adults cannot be expected to be proportionate to that of the neonate or to that of individuals at any particular developmental stage.
Alexander (1979) has invited "⋯ biologists to contribute to the analysis of human behavior on all legitimate fronts⋯" He considered it "⋯ especially relevant that [they] take up the problem of relating human attributes to evolutionary history." The analysis of human sexual behavior surely qualifies as a legitimate topic in evolutionary biology. This chapter represents a contribution to the argument that sperm competition does occur in humans and has been a selective force in the evolution of certain human characteristics. There has been considerable controversy over what may be the "natural" sexual inclinations (promiscuous, polygynous, serially polygynous, monogamous, or some mixture of these) of human males (e.g., Trivers 1972; Wilson 1975; Alexander 1977; Short 1977, 1979, 1981; Daly and Wilson 1978; Symons 1979; Lovejoy 1981; Barash 1982; Harvey and Harcourt, this volume), but relatively much less debate over the sexual predilections of human females (Hrdy 1981). Females are widely assumed to be monogamous, with little formal recognition of alternative female strategies (but see Hrdy 1981, and Knowlton and Greenwell, this volume). The compromise view of human male mating strategy proposes mixed tactics (Trivers 1972) where males attempt to pair-bond with one or more females by high investment, and opportunistically (more or less promiscuously) mate with other females. All combinations of male tactics from rape (Shields and Shields 1983, Thornhill and Thornhill 1983) to high investment (Trivers 1972) and the environmental and social circumstances that occasion their expression have received analysis in the literature. As Hrdy (1981) observed: "The sociobiological literature stresses the travails of males - their quest for different females, the burdens of intra-sexual competition, the entire biological infrastructure for the double standard. No doubt this perspective has led to insights concerning male sexuality. But it has also effectively blocked progress toward understanding female sexuality - defined here as the readiness of a female to engage in sexual activity." The biological irony of the double standard is that males could not have been selected for promiscuity if historically females had always denied them opportunity for expression of the trait. If strict monogamy were the singular human female mating strategy, then only rape would place ejaculates in position to compete and the potential role of sperm competition as a force in human evolution would be substantially diminished. Here I shall explore the literature for evidence of the evolutionary significance of sperm competition in humans. I present data on the circumstances that would place ejaculates from different human males together in the reproductive tract of a female during a single reproductive cycle. I summarize the evidence that human sperm competition actually occurs. And, finally, I speculate on how selection within the context of potential or actual sperm competition may have operated in human evolutionary history to shape some aspects of human anatomy, physiology, behavior, and culture. © 2006 Springer Science+Business Media, Inc. All rights reserved.
Unlike other apes, human females’ breasts develop before first pregnancy and are permanently enlarged. Evidence suggests breasts
act as signals to males but the critical data required to confirm this are lacking. These facts have led to a number of hypotheses
about the evolutionary and adaptive significance of the human breast which fall into two groups. Those that address the presence
of breasts in humans are (a) that they act as releasers of male sexual behaviour, (b) that they enable females to hide their
reproductive condition, and (c) that they allow infants to nurse from their mother’s hip. Those that address variability in
breast size are (d) that large breasts indicate lactational potential, (e) ability of mothers to invest prenatally in offspring,
(f) mother’s fecundity, and (g) her longevity. Each hypothesis is reviewed and evaluated using logical or empirical arguments.
Possible ways in which the adaptive significance of human breasts can be determined in contemporary populations are outlined.
Homo sapiens is unique among primates in that it is the only group-living species in which monogamy is the major mating system and the only species in which females do not reveal their ovulation by estrus. These unique traits can be explained in terms of natural selective and cultural selective theory applied at the level of the individual. The relative amount of parental investment by the sexes is an important correlate with the type of mating systems found in animal species. In human history the evolution of increased hunting abilities, bipedality, relatively altricial young and the concomitant dependency on the male for food by the female are viewed as the factors allowing and favoring increased male parental investment. The same scenario can explain the evolution of extensive female parental care in humans. Monogamy is the result of the male's investment being increased to approximate equality with that of the female and the male's attempt to insure his paternity. The incipient hunting activities of Australopithecus and small cranium would indicate polygyny at this stage of hominid evolution. The increase in hunting activities and brain size of Homo erectus may have favored monogamy. Polygyny may have reappeared to some extent with the evolution of Homo sapiens sapiens 40,000 B.P., but perhaps not until 15,000–11,000 B.P. did disparity in resources controlled by males allow some males to exceed the polygyny threshold. The loss of estrus in the female is regarded not as a precondition to pair-bonding, but as a means for increasing the likelihood of successful cuckoldry of the male after monogamy has been established. The human social setting of monogamous pairs in close proximity greatly reduces the costs of infidelity.
Adaptation has been defined and recognized by two different criteria: historical genesis (features built by natural selection for their present role) and current utility (features now enhancing fitness no matter how they arose). Biologists have often failed to recognize the potential confusion between these different definitions because we have tended to view natural selection as so dominant among evolutionary mechanisms that historical process and current product become one. Yet if many features of organisms are non-adapted, but available for useful cooptation in descendants, then an important concept has no name in our lexicon (and unnamed ideas generally remain unconsidered): features that now enhance fitness but were not built by natural selection for their current role. We propose that such features be called
exaptations
and that adaptation be restricted, as Darwin suggested, to features built by selection for their current role. We present several examples of exaptation, indicating where a failure to conceptualize such an idea limited the range of hypotheses previously available. We explore several consequences of exaptation and propose a terminological solution to the problem of preadaptation.
Allometry should be defined broadly as the study of size and its consequences, not narrowly as the application of power functions to the data of growth. Variation in size may be ontogenetic, static or phyletic. Errors of omission and treatment have plagued the study of allometry in primates. Standard texts often treat brain size as an independent measure, ignoring its allometric relation with body size - on this basis, gracile australopithecines have been accorded the mental status of gorillas. Intrinsic allometries of the brain/body are likewise neglected: many authors cite cerebral folding as evidence of man's mental superiority, but folding is a mechanical correlate of brain size itself. Confusion among types of scaling heads errors of treatment in both historical primacy [Dubois' ontogenetic inferences from interspecific curves] and current frequency. The predicted parameters of brain-body plots differ greatly for ontogenetic, intrapopulational, interspecific and phyletic allometries. I then discuss basic trends in bivariate allometry at the ordinal level for internal organ weights, skeletal dimensions, lifespan and fetal weight. In considering the causes of basic bivariate allometries, I examine the reason for differences among types of scaling in brain-body relationships. The interspecific exponent of 0.66 strongly suggests a relationship to body surfaces, but we have no satisfactory explanation for why this should be so. The tripartite ontogenetic plot is a consequence of patterns in neuronal differentiation. We do not know why intraspecific exponents fall between 0.2 and 0.4; several partial explanations have been offered. Multivariate techniques have transcended the pictorial representation of transformed coordinates and offer new, powerful approaches to total allometric patterns. Allometry is most often used as a 'criterion for subtraction'. In order to assess the nature and purpose of an adaptation, we must be able to identify and isolate the aspect of its form that depends both upon its size and the size of the body within which it resides. Cranial indices and limb lengths are misinterpreted when authors apply no correction for body size. The search for a criterion of subtraction has been most diligently pursued in studies of the brain. Clearly, brain size must be assessed by comparison with a 'standard' animal of the same body size. But how shall size be measured, especially in fossils; and how shall a standard animal be construed. I discuss and criticize three methods recently used: RADINSKY'S foramen magnum criterion; Jerison's minimum convex polygons and cephalization quotients; and the indices of progression in comparison with 'basal' insectivores' of BAUCHOT, Stephan and their colleagues.
This study was undertaken to evaluate the genital anatomy of female newborns. Hymenal configuration and the number and location of clefts, bumps, tags, and ridges were observed in 468 neonates; photographs for confirmation were obtained for 449 neonates (96%). Hymenal configurations observed included an annular hymen with a central or ventrally displaced orifice in 80% (372/468) of neonates, a fimbriated hymen in 19% (90/468), and a septated or cribriform hymen in 1% (6/468). Configurations significantly differed by race (P less than .001) but no difference was noted by gestational age or weight. Clefts, which occurred only on the ventral 180 degrees of the rim, were observed in 34% of neonates with an annular hymen. Fifty-six percent of neonates had a longitudinal intravaginal ridge, 87% had an external hymenal ridge, and 13% had a tag extending from the rim or a ridge. Periurethral ligaments were frequently observed. It is concluded that lateral and ventral clefts, intravaginal and external ridges, and periurethral bands are normal anatomical findings in the newborn.
Complete reproductive tracts of 30 female African elephants (5-53 years), obtained during a population reduction procedure, were examined. The reproductive tracts were palpated in situ via the urogenital canal. A plastic speculum (1.3 X 170 cm) was introduced into the canal and dye was injected to simulate the procedure for artificial insemination. The lengths of reproductive tracts (from the vulva to the ovary) ranged from 120 to 358 cm. The length increased with the size and age of the animal. There was a membranous constriction (hymen) with an orifice, less than 2 cm in diameter, between the urogenital canal and the vagina, in 4 primigravid and in all 13 nulliparous elephants. The vaginal orifice of 13 multiparous elephants consisted of ragged folds of mucous membrane surrounding a single opening, 5-19 cm in diameter. The ages at first conception of 4 pregnant elephants with intact hymenal membranes were 10, 12, 13 and 14 years. The hymen was not penetrated as a result of intromission and therefore the site of ejaculation would have been in the urogenital canal of the 4 primigravid elephants.
The increase in the number of prepubertal girls who require evaluation of possible sexual abuse creates a need for detailed information, not previously available from cross-sectional studies, on the influence of aging on the hymen's appearance. This study was undertaken to evaluate and document, using a longitudinal design, changes in the hymen's morphology in 62 girls without a history of sexual abuse between birth and their first birthday. Labial agglutination extensive enough to obscure the inferior half of the hymen was observed in 5 girls (8%) at 1 year of age. Thirty-three (58%) of the remaining 57 infants experienced a marked decrease in the amount of their hymenal tissue between birth and 1 year. Significantly more infants at 1 year of age had a crescentic configuration (0% vs 28%), and significantly fewer had an external ridge (82% vs 14%) as compared to the newborn period. An annular hymen with a central or ventrally displaced opening progressed to a crescentic hymen in 13 children by 1 year, 77% (10/13) of whom were observed to have a notch (cleft) at the 12 o'clock position on the earlier study. A superior notch appeared for the first time in 9 girls. Lateral notches resolved in 5 cases and persisted in 2. Inferior notches between the 4 and 8 o'clock positions were not observed at birth or 1 year. Hymenal tags resolved in 2 instances, persisted in the same location in 2, and appeared for the first time in 4 cases.(ABSTRACT TRUNCATED AT 250 WORDS)
Hominid bipedality and sexual-selection theory
- Sheets-Johnstone
Sheets-Johnstone M. Hominid bipedality and sexual-selection theory. Evol Theory 1989; 9: 57-70.
Human Evolution and the Baculum
- A Hobday
Hobday A J. Human Evolution and the Baculum. Manuscript in review.
Male nipples and clitoral ripples In: Bully for Brontosaurus: Reflections in Natural History
- S J Gould
Gould S J. Male nipples and clitoral ripples. In: Bully for Brontosaurus: Reflections in Natural History. New York: Norton, 1991: 124--138.
Gray's Anatomy, 36th British edn
- Williams P L E Warwick
Williams P L, Warwick E, eds. Gray's Anatomy, 36th British edn. Philadelphia: W.B. Saunders, 1988.
The Sex Contract: The Evolution of Human Behavior
- H Fisher
Fisher H E. The Sex Contract: The Evolution of Human Behavior. New York: William Morrow, 1982.
Biological Aspects of Human Sexuality
- Katchadorian
Katchadorian H A. Biological Aspects of Human Sexuality, 4th edn. Fort Worth, Texas: Holt, Rinehart & Winston, 1990: 453.
Male nipples and clitoral ripples
- Gould