Sexual maturity is the capability of an
organism
An organism is any life, living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have be ...
to
reproduce. In humans, it is related to both
puberty
Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a female, the testicles i ...
and
adulthood.
''Puberty'' is the biological process of sexual maturation, while ''adulthood'', the condition of being socially recognized as an independent person capable of giving consent and taking responsibility, generally implies sexual maturity (certain
disorders of sexual development notwithstanding), but depends on other criteria, defined by specific
cultural expectations.
Most
multicellular
A multicellular organism is an organism that consists of more than one cell (biology), cell, unlike unicellular organisms. All species of animals, Embryophyte, land plants and most fungi are multicellular, as are many algae, whereas a few organism ...
organisms are unable to
sexually reproduce at birth (animals) or germination (e.g. plants): depending on the species, it may be days, weeks, or years until they have developed enough to be able to do so; in addition, certain cues may trigger an organism to become sexually mature. These may be external, such as drought, or fire, that triggers sexual maturation of certain plants, or internal, such as percentage of body fat (certain animals). Internal cues are not to be confused with
hormones
A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physiology and behavior. Hormones a ...
, the chemical signals that initiate cellular processes leading to sexual maturity, but the production and secretion of hormones is triggered by such cues. In some species, immature males may delay sexual maturation in the presence of another sexually mature male, as in the male
chicken
The chicken (''Gallus gallus domesticus'') is a domesticated subspecies of the red junglefowl (''Gallus gallus''), originally native to Southeast Asia. It was first domesticated around 8,000 years ago and is now one of the most common and w ...
(rooster), due to the intense, often lethal, combat engaged in by mature males. The female
honeybee only becomes sexually mature if it is fed a special substance ("
royal jelly") during the larval stage.
Role of reproductive organs
Sexual maturity is brought about by a maturing of the
reproductive organs and the production of
gamete
A gamete ( ) is a Ploidy#Haploid and monoploid, haploid cell that fuses with another haploid cell during fertilization in organisms that Sexual reproduction, reproduce sexually. Gametes are an organism's reproductive cells, also referred to as s ...
s. It may also be accompanied by a
growth spurt or other physical changes which distinguish the immature organism from its adult form. In animals these are termed
secondary sex characteristic
A secondary sex characteristic is a physical characteristic of an organism that is related to or derived from its sex, but not directly part of its reproductive system. In humans, these characteristics typically start to appear during pubert ...
s, and often represent an increase in
sexual dimorphism
Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...
.
After sexual maturity is achieved, some organisms become
infertile, or even
change their sex. Some organisms are
hermaphrodite
A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic.
The individuals of many ...
s and may or may not be able to "completely" mature and/or to produce viable offspring. Also, while in many organisms sexual maturity is strongly linked to age, many other factors are involved, and it is possible for some to display most or all of the characteristics of the adult form without being sexually mature. Conversely it is also possible for the "immature" form of an organism to reproduce. This is called ''
progenesis'', in which sexual development occurs faster than other physiological development (in contrast, the term ''
neoteny
Neoteny (), also called juvenilization,Montagu, A. (1989). Growing Young. Bergin & Garvey: CT. is the delaying or slowing of the Physiology, physiological, or Somatic (biology), somatic, development of an organism, typically an animal. Neoteny i ...
'' refers to when non-sexual development is slowed – but the result is the same - the retention of juvenile characteristics into adulthood).
Puberty vs. sexual maturity
In some species, there is a difference between puberty and sexual maturity. For example, in
bull
A bull is an intact (i.e., not Castration, castrated) adult male of the species ''Bos taurus'' (cattle). More muscular and aggressive than the females of the same species (i.e. cows proper), bulls have long been an important symbol cattle in r ...
s, puberty is characterized by the accelerated growth of the genital system, an increase in
luteinizing hormone (LH) secretion, and the onset of
spermatogenesis. Sexual maturity, however, signifies the attainment of full reproductive capacity, which may take up to 6–9 months after puberty.
See also
*
Gonadosomatic index
*
Generation time
In population biology and demography
Demography () is the statistical study of human populations: their size, composition (e.g., ethnic group, age), and how they change through the interplay of fertility (births), mortality (deaths), and mi ...
References
{{Authority control
Gynaecological endocrinology
Sexual reproduction
Reproduction
Sexuality
Adulthood