Photograph: Alan Betson. Science has yet to definitively pronounce on whether humans are naturally monogamous lifelong male-female breeding pair or polygamous single male breeding with more than one female. A nicely written summary of this field was written by David Engber in Slate — published on October 9th, Consider testicle size as an indicator of mating habits. Male chimpanzees compete with each other to have sex with as many female chimps as possible.
Orangutan 1 BE15—20 years old, died of chronic pneumonia as a result of a respiratory infection. Coevolution of male and female genital morphology in waterfowl. Dixson 26 January Goilla the community in Kentucky, see Penile, Louisville. This enables them to reach the nearest female for fertilization.
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But what looks like Baritone brass mouthpiece win Sexual organs gorilla man both genders has actually backfired on the male bat bugs. Enthusiastic females initiate both gorklla and homosexual activity, particularly when aggression begins to surface, resulting in satisfied, contented and peaceful bonobos. Carole replies: The origins of the primate sex drive go back more than 60m years to the late Mesozoic era when the first primate evolved. But it hasn't shaped all of them. Mark Maslin, The Cradle of HumanityAuthor provided Male chimpanzees are much larger than females, and they have a multi-male to multi-female mating system. Afar, largo chimps have sex all the Sexual organs gorilla man with any person and with any person. Although chimpanzees are even more promiscuous than humans, the orbans of the male chimp is only half the size of the penis of a man. For woman having sex with a gorilla mature, chimpanzees have edged numerous illustrations in order to time elderly sxe of woman having sex with a gorilla, multiple times a day. The duck vagina twists in the opposite direction, preventing the duck penis from reaching deep inside the female. Second, males need to guard their female from other males. Topics Reproduction Ask Carole.
In relation to their body mass, the testicles and penis of a gorilla are not very noticeable and much smaller than in other apes.
- Anonymous, age and sex unspecified Dear Carole, Why are women so obsessed with the size of a man's cock — wanting ones 6 inches and over and kicking others aside when they really should be concentrating on the emotional connection and love being shared, putting the size of the man's cock right out of her mind?
- It's February
- Great ape sexual organs, compared for size bonobos are flat chested until they get pregnant.
- Our bodies are sacred temples — except for those of us whose temples still need some work to make them a little more standard.
- Humans have a much longer and wider penis than the other great apes.
- Comparing Gorillas and Chimpanzees Proves
E-mail address: azihlman ucsc. Use the link below to share a full-text version of this article with your friends and colleagues. Learn more. Great apes diversified during the Miocene in Old World forests. We test the hypothesis that they increased in body mass independently and convergently, and that their many postcranial differences reflect locomotor differences. Whole body dissections of five adult male gorillas and four adult male orangutans allowed quantification of body mass distribution to limb segments, of body composition muscle, bone, skin, and fat relative to total body mass , and of muscle distribution and proportions.
Results demonstrate that gorilla forelimb anatomy accommodates shoulder joint mobility for vertical climbing and reaching while maintaining joint stability during quadrupedal locomotion. In contrast, orangutan forelimb length, muscle mass, and joint construction are modified for strength and mobility in climbing, bridging, and traveling over flexible supports through the forest canopy.
Muscles of hip, knee, and ankle joints provide rotational and prehensile strength essential for moving on unstable and discontinuous branches. We conclude that anatomical similarities are due to common ancestry and that differences in postcranial anatomy reflect powerful selection for divergent locomotor adaptations.
These data further support the evolutionary conclusion that gorillas fall with chimpanzees and humans as part of the African hominoid radiation; orangutans are a specialized outlier. Anat Rec, Male gorillas Gorilla gorilla gorilla and male orangutans Pongo pygmaeus capture our attention because of our mutual evolutionary proximity and of giantism that led to their extreme sexual dimorphism, locomotor divergence, and geographic isolation.
They originated from a common hominoid lineage about 16 million years ago and diverged about 11 million years ago into African and Asian branches Pilbeam, ; Stauffer et al. Since they likely arose from a smaller common ancestor with the same body structure and locomotor skills, the development of large body size and unique sexually dimorphic anatomies is convergent Zihlman, A profile of segment proportions, body composition, and distribution of muscle is the central test for the hypothesis that their similarities are due to common descent, whereas postcranial differences are due to locomotor divergence as a result of geographical isolation in different habitats.
Historically, anatomical investigations of apes were based on a single animal, on one limb or body region, or on descriptions of body shape, internal organs, skin, and hair or muscle attachments e. The volume reports on muscle attachments, the skeleton, the nervous and vascular systems, the skin, and thoracic viscera. However, other than weights of some organs Steiner, the volume has no quantitative or functional information. Other approaches to gorilla and orangutan anatomy have addressed function with quantitative information by focusing on one component, for example skeletal proportions e.
On live captive gorillas and orangutans, direct measures of muscle function or joint motion derive from electromyography during specific limb movements e. Few comparative studies focus on joints and the associated soft tissue; both are important, but the opportunity for their combined study is rare e.
Whole animals provide multiple ways to analyze and compare, for example body segments relative to total body mass TBM , forelimb to hind limb mass, joint configuration, and corresponding muscles.
Although description of individual bones, muscles, segment weights, single limbs or joints can be a starting point, our whole body analysis also incorporates information about locomotion, energetics, and environment; this robust methodology results in an integrated approach for comparing and testing hypotheses about adaptation.
As a first step, we present, as a unique baseline, dissection data on nine adult males that quantify distribution of body mass to segments, and body composition muscle, bone, skin, and fat. We further analyze muscle distribution, joint properties, and functional muscle groups.
Medical and health records for each individual help evaluate the impact of age and wellness on body composition. Such analyses are almost nonexistent due to the rarity of whole gorillas and orangutans available for dissection. Finally, to test our hypothesis about adaptation, we compare field observations on the locomotor challenges of travel, foraging, and feeding.
This contextualizes the anatomy by connecting function to structure Davis, This approach extends the role of comparative anatomy and the contribution it must play in the interpretation of evolutionary history, that is, the inclusion of soft tissue in analyzes to evaluate divergence from a common ancestor. The five silverback lowland gorillas all G. Body weights taken during life, just before death, or at time of necropsy are available for the sample.
Information recorded during their lives helps interpret anatomical findings from this unique data set. Table 1 a. Gorilla 1 MO , 37, wild born Cameroon , lived from about age 2 years in captivity and is the oldest in the sample.
He suffered from chronic heart failure that became acute during the last 4—6 weeks of life, leading to edema, pneumonia, multiple organ failure, and loss of body mass. At death he was the lightest. Gorilla 2 MI , 27, wild born Cameroon was housed in a large outdoor grassy enclosure with multiple structures for climbing.
He is the youngest, leanest and most muscular of the sample and was in the prime of life. He exhibited no overt health problems, but died of sudden cardiac arrest due to undetected fibrosing cardiomyopathy. Gorilla 3 BW , 36, wild born Cameroon , lived in captivity from about age 18 months, was housed in a social group, and sired three offspring.
His last 14 years were spent in a large outdoor, grassy enclosure with trees and rocky structures. He was generally healthy during life, though he died within a week from a perforated ileum. Gorilla 4 KU , 29, was sired by male Gorilla 3 BW and lived his entire life in his natal social group where he fathered three offspring. For several years, he suffered a chronic lung infection that became acute; he died as a result of surgery to save his life.
Gorilla 5 CO , 36, wild born from an unknown locality in western Africa, was a large, robust individual, very well muscled, although described as obese in his medical records.
The orangutan sample consists of four flanged adult males who lived most of their lives in captivity. Grand contributed data from his two orangutan dissections. Table 1 b. Orangutan 1 BE , 15—20 years old, died of chronic pneumonia as a result of a respiratory infection. Orangutan 2 TH , 31, was dissected by T. Grand at the National Zoological Park, Smithsonian. Only individual muscle weights are available for this animal.
Orangutan 3 BU , 24, was Bornean, born and raised in captivity. He died of peritonitis after a brief illness. Orangutan 4 JI from the Cheyenne Mountain Zoo was very obese and died as a result of a canine tooth infection that spread to his brain. Grand and his anatomy class at University of Colorado, Boulder dissected him. His body mass was estimated based on the combined mass of the dissected parts. Body composition is not included in the orangutan average but is included in the discussion on variation.
The bodies were received frozen, were thawed, and then dissected. On one side of the body, referred to as the segment side, we separate the entire forelimb at the shoulder joint by cutting the skin around the joint, releasing trunk and rotator cuff muscles from the humerus, and the arm muscles from the trunk. We then partition the limb into three pieces: the upper arm segment is separated at the elbow joint; the hand segment is severed from the forearm segment by cutting through the tendons and ligaments at the radiocarpal joint.
Similarly, we separate the hind limb at the hip joint by cutting the skin around the inguinal region, below the ischium to the pubic symphysis. The hip muscles are detached from the femur and the thigh muscles from the innominate. We weigh the entire hind limb, and then each segment is weighed immediately after it is detached.
Bone, skin, and other tissues are separated and weighed as the dissection of that region proceeds. We measure hand length from midradiocarpal joint to tip of third digit, and foot length from heel calcaneus to tip of third digit on intact segments; maximum lengths of long bones are taken on cleaned specimens. We calculate the contribution of the forelimbs by doubling the weight of the forelimb segment to represent both limbs, then calculate its percentage relative to TBM.
Similarly, we double the weight of the hind limb segment and calculate as a percent of TBM. We calculate the contribution of each segment of the forelimb arm, forearm, and hand relative to total forelimb mass. Similarly, we calculate each segment of the hind limb thigh, leg, and foot relative to total hind limb mass. Adipose tissue is an important component of body mass but is rarely available as a direct measure. At necropsy, thoracic and abdominal contents, which include fat, are routinely removed.
To this total, we add the body fat recorded during dissection, for example, orangutan cheek pads, and intermuscular fat and any remaining fat on the walls within the trunk cavity. This method, applied consistently, provides a rough approximation of body fat for the individuals in this study.
To determine its regional distribution to the forelimbs, we add all muscle from the arm, forearm, and hand segments, plus the rotator cuff and external trunk muscles Table 2 that act on the humerus; we calculate this amount as a percent of total body muscle. Similarly, for the hind limb, we add all muscle from the thigh, leg, and foot segments, as well as hip joint muscles that attach to the femur and calculate relative to total body muscle.
We group muscles according to their functional relationship to joints, that is, muscles that pull in the same direction, and determine percent profiles based on individual muscle weights Table 2. We determine relative contribution of elbow flexors and extensors to their combined mass; and do the same with wrist flexors and extensors; and digital flexors and extensors after Grand, a ; Tuttle, Hip joint muscles are grouped to approximate movement potentials after Grand, b.
Knee extensors quadriceps femoris and the posterior flexors hamstrings are calculated as a percent of combined mass. At the ankle, the contribution of plantar flexors to dorsiflexors is determined; invertors to evertors at the subtalar joint, and the digital flexors to extensors.
We calculate the relative contribution of segments within each limb: humerus, radius, hand relative to total forelimb length; femur, tibia, and foot relative to total hind limb segment length. After the skull is cleaned and dried, we calculate cranial capacity using mustard seed after Bolter and Zihlman Small samples limit statistics to means and ranges; to supplement, we provide raw data on body composition, and limb segments Table 3.
Gorillas and orangutans show distinct patterns in distribution of body mass to the limbs and in the segments within the limbs. Gorillas' heavy proximal segments arm and thigh contrast with orangutans' equal arm and forearm mass, and heavy hand Fig.
Gorillas have less muscle in the forelimbs than in the hind limbs; orangutan forelimb muscle is heavier, hind limb lighter, and the ranges of the two species do not overlap. Relative muscle weights serve as gross approximations of their functional importance e. Individual muscles of the limb, when available, are listed in Table 4 and Fig.
Of total body musculature, In gorillas, latissimus dorsi comprises The gorilla humeral head is somewhat restricted, in contrast to the less confined orangutan's due to the scapula's less projecting acromion and coracoid processes and a shallower glenoid fossa Fig.
Ratios of elbow flexors and extensors differ in the two species, and the ranges do not overlap. Gorilla flexors are In orangutans, the flexors are The bony joint architecture reflects the differences in muscle mass and function. Of gorilla forelimb musculature,
Women have been urged not to walk home alone after a sex beast wearing a Star Wars Yoda mask and gorilla masks launched a terrifying knifepoint attack. Presumably, their mother is happy to be healthy as well, after such an unlikely and dangerous pregnancy. Females may not be particularly happy about being manipulated like this , though. This can be shown by observing chimpanzees and gorillas, our closest living relatives. When compared with patriarchal chimps, the matriarchal bonobo is a far more sex-oriented ape.
Sexual organs gorilla man. Not all males have pimped out genitalia...
Bristol Zoo male gorilla revealed to be a female - BBC News
The term penis applies to many intromittent organs , but not to all; for example the intromittent organ of most cephalopoda is the hectocotylus , a specialised arm, and male spiders use their pedipalps.
Even within the Vertebrata there are morphological variants with specific terminology, such as hemipenes. In most species of animals in which there is an organ that might reasonably be described as a penis, it has no major function other than intromission, or at least conveying the sperm to the female, but in the placental mammals the penis bears the distal part of the urethra , which discharges both urine during urination and semen during copulation.
Most male birds e. Among bird species with a penis are paleognathes tinamous and ratites  and Anatidae ducks, geese and swans. While most male birds have no external genitalia, male waterfowl Anatidae have a phallus.
Most birds mate with the males balancing on top of the females and touching cloacas in a "cloacal kiss"; this makes forceful insemination very difficult. The phallus that male waterfowl have evolved everts out of their bodies in a clockwise coil and aids in inseminating females without their cooperation.
These structures make it harder for males to achieve intromission. The clockwise coils are significant because the male phallus everts out of their body in a counter-clockwise spiral; therefore, a clockwise vaginal structure would impede forceful copulation. Studies have shown that the longer a male's phallus is, the more elaborate the vaginal structures were. The lake duck is notable for possessing, in relation to body length, the longest penis of all vertebrates ; the penis, which is typically coiled up in flaccid state, can reach about the same length as the animal himself when fully erect, but is more commonly about half the bird's length.
Male and female emus are similar in appearance,  although the male's penis can become visible when it defecates. The male tinamou has a corkscrew shaped penis, similar to those of the ratites and to the hemipenis of some reptiles.
Females have a small phallic organ in the cloaca which becomes larger during the breeding season. As with any other bodily attribute, the length and girth of the penis can be highly variable between mammals of different species.
A bone called the baculum or os penis is present in most mammals but absent in humans, cattle and horses. In mammals the penis is divided into three parts: . The internal structures of the penis consist mainly of cavernous, erectile tissue , which is a collection of blood sinusoids separated by sheets of connective tissue trabeculae.
Some mammals have a lot of erectile tissue relative to connective tissue, for example horses. Because of this a horse's penis can enlarge more than a bull's penis. The urethra is on the ventral side of the body of the penis. In comparison, the human penis is larger than that of any other primate , both in proportion to body size and in absolute terms.
The penises of even-toed ungulates are curved in an S-shape when not erect. When mating, the tip of a male pronghorn 's penis is often the first part to touch the female pronghorn. Copulation time ranges from 7 to 35 minutes, averaging 11—15 minutes. Bulls have a fibro-elastic penis. Given the small amount of erectile tissue, there is little enlargement after erection.
The penis is quite rigid when non-erect, and becomes even more rigid during erection. Protrusion is not affected much by erection, but more by relaxation of the retractor penis muscle and straightening of the sigmoid flexure.
The male genitalia of mouse deer are similar to those of pigs. The purpose of this is not fully understood. A stag's penis forms an S-shaped curve when it is not erect, and is retracted into its sheath by the retractor penis muscle. Cetaceans' reproductive organs are located inside the body. Male cetaceans whales, dolphins, and porpoises have two slits, the genital groove concealing the penis and one further behind for the anus.
The penis on a right whale can be up to 2. Stallions male horses have a vascular penis. When non-erect, it is quite flaccid and contained within the prepuce foreskin, or sheath.
Tapirs have exceptionally long penises relative to their body size. All members of Carnivora except hyenas have a baculum. During copulation, the spotted hyena inserts his penis through the female's pseudo-penis instead of directly through the vagina , which is blocked by the false scrotum and testes. Once the female retracts her clitoris, the male enters the female by sliding beneath her, an operation facilitated by the penis's upward angle.
Domestic cats have barbed penises, with about — one millimeter long backwards-pointing spines. Lions also have barbed penises. The male fossa has an unusually long penis and baculum penis bone , reaching to between his front legs when erect  withbackwards-pointing spines along most of its length.
The beech marten 's penis is larger than the pine marten's, with the bacula of young beech martens often outsizing those of old pine martens. Raccoons have penis bones which bend at a 90 degree angle at the tip. Male walruses possess the largest penis bones of any land mammal, both in absolute size and relative to body size. The adult male American mink 's penis is 2.
The baculum is well-developed, being triangular in cross section and curved at the tip. Males of Racey's pipistrelle bat have a long, straight penis with a notch between the shaft and the narrow, egg-shaped glans penis.
Near the top, the penis is haired, but the base is almost naked. In the baculum penis bone , the shaft is long and narrow and slightly curved. Copulation by male greater short-nosed fruit bats is dorsoventral and the females lick the shaft or the base of the male's penis, but not the glans which has already penetrated the vagina.
While the females do this, the penis is not withdrawn and research has shown a positive relationship between length of the time that the penis is licked and the duration of copulation. Post copulation genital grooming has also been observed. The glans penis of the marsh rice rat is long and robust,  averaging 7. The papilla nipple-like projection on the dorsal upper side of the penis is covered with small spines, a character the marsh rice rat shares only with Oligoryzomys and Oryzomys couesi among oryzomyines examined.
In Transandinomys talamancae , the outer surface of the penis is mostly covered by small spines, but there is a broad band of nonspinous tissue. Some features of the accessory glands in the male genital region vary among oryzomyines.
In Transandinomys talamancae ,  a single pair of preputial glands is present at the penis. As is usual for sigmodontines, there are two pairs of ventral prostate glands and a single pair of anterior and dorsal prostate glands.
Part of the end of the vesicular gland is irregularly folded, not smooth as in most oryzomyines. In Pseudorhyzomys, the baculum penis bone displays large protuberances at the sides. In the cartilaginous part of the baculum, the central digit is smaller than those at the sides. In Drymoreomys , there are three digits at the tip of the penis, of which the central one is the largest. In Thomasomys ucucha the glans penis is rounded, short, and small and is superficially divided into left and right halves by a trough at the top and a ridge at the bottom.
The glans penis of a male cape ground squirrel is large with a prominent baculum. Unlike other squirrel species, red squirrels have long, thin, and narrow penises, without a prominent baculum. Winkelmann's mouse can easily be distinguished from its close relatives by the shape of its penis, which has a partially corrugated glans.
The foreskin of a capybara is attached to the anus in an unusual way, forming an anogenital invagination. It has been postulated that the shape of the human penis may have been selected by sperm competition.
The shape could have favored displacement of seminal fluids implanted within the female reproductive tract by rival males: the thrusting action which occurs during sexual intercourse can mechanically remove seminal fluid out of the cervix area from a previous mating. The penile morphology of some types of strepsirrhine primates has provided information about their taxonomy.
They are less densely packed than in Otolemur crassicaudatus. The adult male of each vervet monkey species has a pale blue scrotum and a red penis,   and male proboscis monkeys have a red penis with a black scrotum.
Male baboons and squirrel monkeys sometimes gesture with an erect penis as both a warning of impending danger and a threat to predators. The human penis is an external sex organ of male humans. It is a reproductive , intromittent organ that additionally serves as the urinal duct. The main parts are the root of the penis radix : It is the attached part, consisting of the bulb of penis in the middle and the crus of penis , one on either side of the bulb; the body of the penis corpus ; and the epithelium of the penis consists of the shaft skin , the foreskin , and the preputial mucosa on the inside of the foreskin and covering the glans penis.
The human penis is made up of three columns of tissue : two corpora cavernosa lie next to each other on the dorsal side and one corpus spongiosum lies between them on the ventral side.
It is a passage both for urine and for the ejaculation of semen. In males, the expulsion of urine from the body is done through the penis. The urethra drains the bladder through the prostate gland where it is joined by the ejaculatory duct , and then onward to the penis. An erection is the stiffening and rising of the penis, which occurs during sexual arousal , though it can also happen in non-sexual situations. Ejaculation is the ejecting of semen from the penis, and is usually accompanied by orgasm.
A series of muscular contractions delivers semen, containing male gametes known as sperm cells or spermatozoa , from the penis. The most common form of genital alteration is circumcision : removal of part or all of the foreskin for various cultural, religious, and more rarely medical reasons. There is controversy surrounding circumcision.
As of [update] , a systematic review of 15, men, and the best research to date on the topic, as the subjects were measured by health professionals, rather than self-measured, has concluded that the average length of an erect human penis is Most marsupials, except for the two largest species of kangaroos and marsupial moles  assuming the latter are true marsupials , have a bifurcated penis , separated into two columns, so that the penis has two ends corresponding to the females' two vaginas.
Monotremes and marsupial moles are the only mammals in which the penis is located inside the cloaca. Male echidnas have a bilaterally symmetrical, rosette-like, four-headed penis. The heads used are swapped each time the mammal copulates. The male echidna's penis is 7 centimetres 2. The penis of the bush hyrax is complex and distinct from that of the other hyrax genera. It has a short, thin appendage within a cup-like glans penis and measures greater than 6 centimetres 2.
Additionally, it has been observed that the bush hyrax also has a greater distance between the anus and preputial opening in comparison to other hyraxes. An adult elephant has the largest penis of any land animal.