90 relations: Abdominal hair, Adam's apple, Aggression, Anatomical terms of motion, Androgen, Animal coloration, Antelope, Biology, Body fat percentage, Body hair, Bone, Breast, Buttocks, Charles Darwin, Chest hair, Courtship, Desmond Morris, Dihydrotestosterone, Elephant seal, Endometrium, Epiphyseal plate, Estradiol, Estrogen, Face, Facial hair, Fat, Femur, Fisherian runaway, Fitness (biology), Foot, Gestation, Goat, Gonad, Hand, Handicap principle, Hip, Hormone, Human, Human height, Human voice, Jumping spider, Larynx, Lion, Mandrill, Menstrual cycle, Metabolism, Morphology (biology), Muscle, Narwhal, Nipple, ..., Nose, Pattern hair loss, Peafowl, Phenotypic trait, Plumage, Positive feedback, Preadolescence, Proboscis, Proboscis monkey, Prostate, Puberty, Pubic hair, Reproductive system, Ronald Fisher, Sex, Sex organ, Sex steroid, Sexual characteristics, Sexual differentiation, Sexual dimorphism, Sexual maturity, Sexual reproduction, Sexual selection, Sexy son hypothesis, Shoulder, Skeleton, Skull, Structure, Subcutaneous tissue, Sweat gland, Testosterone, The American Naturalist, The Descent of Man, and Selection in Relation to Sex, The Genetical Theory of Natural Selection, Thigh, Underarm hair, Uterus, Vocal folds, Vulva, Waist–hip ratio. Expand index (40 more) » « Shrink index
Abdominal hair is the hair that grows on the abdomen of humans and non-human mammals, in the region between the pubic area and the thorax (chest).
The Adam's apple, or laryngeal prominence, is a feature of the human neck, and is the lump or protrusion that is formed by the angle of the thyroid cartilage surrounding the larynx seen especially in males.
Aggression is overt, often harmful, social interaction with the intention of inflicting damage or other unpleasantness upon another individual.
Motion, the process of movement, is described using specific anatomical terms.
An androgen (from Greek andr-, the stem of the word meaning "man") is any natural or synthetic steroid hormone which regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors.
Animal coloration is the general appearance of an animal resulting from the reflection or emission of light from its surfaces.
An antelope is a member of a number of even-toed ungulate species indigenous to various regions in Africa and Eurasia.
Biology is the natural science that studies life and living organisms, including their physical structure, chemical composition, function, development and evolution.
The body fat percentage (BFP) of a human or other living being is the total mass of fat divided by total body mass, times 100; body fat includes essential body fat and storage body fat.
Body hair, or androgenic hair, is the terminal hair that develops on the human body during and after puberty.
A bone is a rigid organ that constitutes part of the vertebrate skeleton.
The breast is one of two prominences located on the upper ventral region of the torso of primates.
The buttocks (singular: buttock) are two rounded portions of the anatomy, located on the posterior of the pelvic region of primates (including humans), and many other bipeds or quadrupeds, and comprise a layer of fat superimposed on the gluteus maximus and gluteus medius muscles.
Charles Robert Darwin, (12 February 1809 – 19 April 1882) was an English naturalist, geologist and biologist, best known for his contributions to the science of evolution.
Chest hair is hair that grows on the chest of a person in the region between the neck and the abdomen.
Courtship is the period of development towards an intimate relationship wherein people (usually a couple) get to know each other and decide if there will be an engagement or other romantic arrangement.
Desmond John Morris (born 24 January 1928) is an English zoologist, ethologist and surrealist painter, as well as a popular author in human sociobiology.
Dihydrotestosterone (DHT), or 5α-dihydrotestosterone (5α-DHT), also known as androstanolone or stanolone, is an endogenous androgen sex steroid and hormone.
Elephant seals are large, oceangoing earless seals in the genus Mirounga.
The endometrium is the inner epithelial layer, along with its mucous membrane, of the mammalian uterus.
The epiphyseal plate (or epiphysial plate, physis, or growth plate) is a hyaline cartilage plate in the metaphysis at each end of a long bone.
Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone.
Estrogen, or oestrogen, is the primary female sex hormone.
The face is a central body region of sense and is also very central in the expression of emotion among humans and among numerous other species.
Facial hair is hair grown on the face, usually on the chin, cheeks, and upper lip region.
Fat is one of the three main macronutrients, along with carbohydrate and protein.
The femur (pl. femurs or femora) or thigh bone, is the most proximal (closest to the hip joint) bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles including lizards, and amphibians such as frogs.
Fisherian runaway or runaway selection is a sexual selection mechanism proposed by the mathematical biologist Ronald Fisher in the early 20th century, to account for the evolution of exaggerated male ornamentation by persistent, directional female choice.
Fitness (often denoted w or ω in population genetics models) is the quantitative representation of natural and sexual selection within evolutionary biology.
The foot (plural feet) is an anatomical structure found in many vertebrates.
Gestation is the carrying of an embryo or fetus inside viviparous animals.
The domestic goat (Capra aegagrus hircus) is a subspecies of goat domesticated from the wild goat of southwest Asia and Eastern Europe.
A gonad or sex gland or reproductive gland is a mixed gland that produces the gametes (sex cells) and sex hormones of an organism.
A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs.
The handicap principle is a hypothesis originally proposed in 1975 by Israeli biologist Amotz Zahavi to explain how evolution may lead to "honest" or reliable signaling between animals which have an obvious motivation to bluff or deceive each other.
In vertebrate anatomy, hip (or "coxa"Latin coxa was used by Celsus in the sense "hip", but by Pliny the Elder in the sense "hip bone" (Diab, p 77) in medical terminology) refers to either an anatomical region or a joint.
A hormone (from the Greek participle “ὁρμῶ”, "to set in motion, urge on") is any member of a class of signaling molecules produced by glands in multicellular organisms that are transported by the circulatory system to target distant organs to regulate physiology and behaviour.
Humans (taxonomically Homo sapiens) are the only extant members of the subtribe Hominina.
Human height or stature is the distance from the bottom of the feet to the top of the head in a human body, standing erect.
The human voice consists of sound made by a human being using the vocal tract, such as talking, singing, laughing, crying, screaming, etc.
Jumping spiders are a group of spiders that constitute the family Salticidae.
The larynx, commonly called the voice box, is an organ in the top of the neck of tetrapods involved in breathing, producing sound, and protecting the trachea against food aspiration.
The lion (Panthera leo) is a species in the cat family (Felidae).
The mandrill (Mandrillus sphinx) is a primate of the Old World monkey (Cercopithecidae) family.
The menstrual cycle is the regular natural change that occurs in the female reproductive system (specifically the uterus and ovaries) that makes pregnancy possible.
Metabolism (from μεταβολή metabolē, "change") is the set of life-sustaining chemical transformations within the cells of organisms.
Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features.
Muscle is a soft tissue found in most animals.
The narwhal (Monodon monoceros), or narwhale, is a medium-sized toothed whale that possesses a large "tusk" from a protruding canine tooth.
The nipple is a raised region of tissue on the surface of the breast from which milk leaves the breast through the lactiferous ducts.
A nose is a protuberance in vertebrates that houses the nostrils, or nares, which receive and expel air for respiration alongside the mouth.
Pattern hair loss, known as male-pattern hair loss (MPHL) when it affects males and female-pattern hair loss (FPHL) when it affects females, is hair loss that primarily affects the top and front of the scalp.
The peafowl include three species of birds in the genera Pavo and Afropavo of the Phasianidae family, the pheasants and their allies.
A phenotypic trait, or simply trait, is a distinct variant of a phenotypic characteristic of an organism; it may be either inherited or determined environmentally, but typically occurs as a combination of the two.
Plumage ("feather") refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers.
Positive feedback is a process that occurs in a feedback loop in which the effects of a small disturbance on a system include an increase in the magnitude of the perturbation.
Preadolescence, also known as pre-teen or tween, is a stage of human development following early childhood and preceding adolescence.
A proboscis is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate.
The proboscis monkey (Nasalis larvatus) or long-nosed monkey, known as the bekantan in Indonesia, is a reddish-brown arboreal Old World monkey with an unusually large nose.
The prostate (from Ancient Greek προστάτης, prostates, literally "one who stands before", "protector", "guardian") is a compound tubuloalveolar exocrine gland of the male reproductive system in most mammals.
Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction.
Pubic hair is terminal body hair that is found in the genital area of adolescent and adult humans.
The reproductive system or genital system is a system of sex organs within an organism which work together for the purpose of sexual reproduction.
Sir Ronald Aylmer Fisher (17 February 1890 – 29 July 1962), who published as R. A. Fisher, was a British statistician and geneticist.
Organisms of many species are specialized into male and female varieties, each known as a sex. Sexual reproduction involves the combining and mixing of genetic traits: specialized cells known as gametes combine to form offspring that inherit traits from each parent.
A sex organ (or reproductive organ) is any part of an animal's body that is involved in sexual reproduction.
Sex steroids, also known as gonadocorticoids and gonadal steroids, are steroid hormones that interact with vertebrate androgen or estrogen receptors.
Sexual characteristics are physical or behavioral traits of an organism (typically of a sexually dimorphic organism) which are indicative of its biological sex.
Sexual differentiation is the process of development of the differences between males and females from an undifferentiated zygote.
Sexual dimorphism is the condition where the two sexes of the same species exhibit different characteristics beyond the differences in their sexual organs.
Sexual maturity is the capability of an organism to reproduce.
Sexual reproduction is a form of reproduction where two morphologically distinct types of specialized reproductive cells called gametes fuse together, involving a female's large ovum (or egg) and a male's smaller sperm.
Sexual selection is a mode of natural selection where members of one biological sex choose mates of the other sex to mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex (intrasexual selection).
The sexy son hypothesis in evolutionary biology and sexual selection—proposed by Ronald Fisher in 1930—states that a female's ideal mate choice among potential mates is one whose genes will produce male offspring with the best chance of reproductive success.
The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) as well as associated muscles, ligaments and tendons.
The skeleton is the body part that forms the supporting structure of an organism.
The skull is a bony structure that forms the head in vertebrates.
Structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized.
The subcutaneous tissue, also called the hypodermis, hypoderm, subcutis, or superficial fascia, is the lowermost layer of the integumentary system in vertebrates.
Sweat glands, also known as sudoriferous or sudoriparous glands,, are small tubular structures of the skin that produce sweat.
Testosterone is the primary male sex hormone and an anabolic steroid.
The American Naturalist is a monthly peer-reviewed scientific journal that was established in 1867.
The Descent of Man, and Selection in Relation to Sex is a book by English naturalist Charles Darwin, first published in 1871, which applies evolutionary theory to human evolution, and details his theory of sexual selection, a form of biological adaptation distinct from, yet interconnected with, natural selection.
The Genetical Theory of Natural Selection is a book by Ronald Fisher which combines Mendelian genetics with Charles Darwin's theory of natural selection, with Fisher being the first to argue that "Mendelism therefore validates Darwinism" and stating with regard to mutations that "The vast majority of large mutations are deleterious; small mutations are both far more frequent and more likely to be useful", thus refuting orthogenesis.
In human anatomy, the thigh is the area between the hip (pelvis) and the knee.
Underarm hair, also known as axillary hair, is the hair in the underarm area (axilla).
The uterus (from Latin "uterus", plural uteri) or womb is a major female hormone-responsive secondary sex organ of the reproductive system in humans and most other mammals.
The vocal folds, also known commonly as vocal cords or voice reeds, are composed of twin infoldings of mucous membrane stretched horizontally, from back to front, across the larynx.
The vulva (wrapper, covering, plural vulvae or vulvas) consists of the external female sex organs.
The Waist-hip ratio or waist-to-hip ratio (WHR) is the dimensionless ratio of the circumference of the waist to that of the hips.
Evolution of secondary sex characteristics, Secondary sex characteristics, Secondary sexual character, Secondary sexual characteristic, Secondary sexual characteristics, Secondarysexualcharacteristics.