Information about Parental Investment
In evolutionary biology, parental investment (PI) is any parental expenditure (time, energy etc.) that benefits one offspring at a cost to parents' ability to invest in other components of fitness (Clutton-Brock 1991: 9; Trivers 1972). Components of fitness (Beatty 1992) include the wellbeing of existing offspring, parents' future reproduction, and inclusive fitness through aid to kin (Hamilton, 1964). Parental investment is sometimes incorrectly equated with parental care or parental effort. Parental investment theory is a branch of life history theory. This potential negative effect of parental care was explicitly formalised by Trivers (1972) who originally defined the term parental investment to mean any investment by the parent in an individual offspring that increases the offspring's chance of surviving (and hence reproductive success) at the cost of the parent's ability to invest in other offspring. Clutton-Brock (1991: 9) expanded the concept of PI to include costs to any other component of parental fitness.
Robert Trivers' theory of parental investment predicts that the sex making the largest investment in lactation, nurturing and protecting offspring will be more discriminating in mating and that the sex that invests less in offspring will compete for access to the higher investing sex (see Bateman's principle). Sex differences in parental effort are important in determining the strength of sexual selection.
Reproduction is costly. Individuals are limited in the degree to which they can devote time and resources to producing and raising their young, and such expenditure may also be detrimental to their future condition, survival and further reproductive output. However, such expenditure is typically beneficial to the offspring, enhancing their condition, survival and reproductive success. These differences may lead to parent-offspring conflict. Parental investment can be provided by the female (female uniparental care), the male (male uniparental care), or both (biparental care). Parents are naturally selected to maximise the difference between the benefits and the costs, and parental care will tend to exist when the benefits are substantially greater than the costs.
Parental care is found in a broad range of taxonomic groups including both ectothermic (invertebrates, fish, amphibians and reptiles) and endothermic (birds and mammals) species. Care can be provided at any stage of the offspring life: pre-natal care including behaviours such as egg guarding, preparation of nest, brood carrying, incubation and placental nourishment in mammals and post-natal care including food provisioning, protection of offspring.
Since both males and females go through several reproductive bouts during their lifetime, it is expected that parents trade-off the benefits of investing in current offspring against the costs to future reproduction. In particular, parents need to balance their offspring demands against their own self-maintenance. The benefits of parental investment to the offspring are large and are associated with the effects on condition, growth, survival and ultimately, on reproductive success of the offspring. However, these benefits can come at the cost of parent's ability to reproduce in the future e.g. through the increased risk of injury when defending offspring against predators, the loss of mating opportunities whilst rearing offspring and an increase in the time to the next reproduction. Overall, parents are selected to maximise the difference between the benefits and the costs, and parental care will be likely to evolve when the benefits are higher than the costs.
..... Click the link for more information.
Robert Trivers' theory of parental investment predicts that the sex making the largest investment in lactation, nurturing and protecting offspring will be more discriminating in mating and that the sex that invests less in offspring will compete for access to the higher investing sex (see Bateman's principle). Sex differences in parental effort are important in determining the strength of sexual selection.
Reproduction is costly. Individuals are limited in the degree to which they can devote time and resources to producing and raising their young, and such expenditure may also be detrimental to their future condition, survival and further reproductive output. However, such expenditure is typically beneficial to the offspring, enhancing their condition, survival and reproductive success. These differences may lead to parent-offspring conflict. Parental investment can be provided by the female (female uniparental care), the male (male uniparental care), or both (biparental care). Parents are naturally selected to maximise the difference between the benefits and the costs, and parental care will tend to exist when the benefits are substantially greater than the costs.
Parental care is found in a broad range of taxonomic groups including both ectothermic (invertebrates, fish, amphibians and reptiles) and endothermic (birds and mammals) species. Care can be provided at any stage of the offspring life: pre-natal care including behaviours such as egg guarding, preparation of nest, brood carrying, incubation and placental nourishment in mammals and post-natal care including food provisioning, protection of offspring.
Since both males and females go through several reproductive bouts during their lifetime, it is expected that parents trade-off the benefits of investing in current offspring against the costs to future reproduction. In particular, parents need to balance their offspring demands against their own self-maintenance. The benefits of parental investment to the offspring are large and are associated with the effects on condition, growth, survival and ultimately, on reproductive success of the offspring. However, these benefits can come at the cost of parent's ability to reproduce in the future e.g. through the increased risk of injury when defending offspring against predators, the loss of mating opportunities whilst rearing offspring and an increase in the time to the next reproduction. Overall, parents are selected to maximise the difference between the benefits and the costs, and parental care will be likely to evolve when the benefits are higher than the costs.
References
- Bateman, A. J. 1948. Intra-sexual selection in Drosophila. Heredity 2: 349-368.
- Beatty, John. 1992. "Fitness: theoretical contexts," in Key Words in Evolutionary Biology. Edited by EF Keller and EA Lloyd, pp. 115-9. Cambridge, MA: Havard U.Press.
- Clutton-Brock, T.H. 1991. The Evolution of Parental Care. Princeton, NJ: Princeton U. Press.
- Clutton-Brock, T.H. and C. Godfray. 1991. "Parental investment," in Behavioural Ecology: An Evolutionary Approach. Edited by J.R. Krebs and N.B. Davies, pp. 234-262. Boston: Blackwell.
- Hamilton, W.D. 1964. The genetical evolution of social behavior. Journal of Theoretical Biology 7:1-52.
- Trivers, R.L. (1972). Parental investment and sexual selection. In B. Campbell (Ed.), Sexual selection and the descent of man, 1871-1971 (pp. 136-179). Chicago, IL: Aldine. ISBN 0-435-62157-2
Further reading
- Geary, D. C. (2005). Evolution of paternal investment. In D. M. Buss (Ed.), The evolutionary psychology handbook (pp. 483-505). Hoboken, NJ: John Wiley & Sons. Full text
Evolutionary biology is a sub-field of biology concerned with the origin and descent of species, as well as their change, multiplication, and diversity over time.
..... Click the link for more information.
..... Click the link for more information.
Parental expenditure is a term used by R.A. Fisher in his 1930 book The Genetical Theory of Natural Selection to describe the opportunity cost that parents spend in producing and rearing children.
..... Click the link for more information.
..... Click the link for more information.
offspring are the product of reproduction, a new organism produced by one or more parents.
Collective offspring may be known as a brood or progeny in a more general way.
..... Click the link for more information.
Collective offspring may be known as a brood or progeny in a more general way.
..... Click the link for more information.
parent is a father or mother; one who sires or gives birth to and/or nurtures and raises an offspring. The different role of parents varies throughout the tree of life, and is especially complex in human culture.
..... Click the link for more information.
..... Click the link for more information.
Fitness (often denoted in population genetics models) is a central concept in evolutionary theory. It describes the capability of an individual of certain genotype to reproduce, and usually is equal to the proportion of the individual's genes in all the genes of the next generation.
..... Click the link for more information.
..... Click the link for more information.
Sexual reproduction is a union that results in increasing genetic diversity of the offspring. It is characterized by two processes: meiosis, involving the halving of the number of chromosomes; and fertilisation, involving the fusion of two gametes and the restoration of the
..... Click the link for more information.
..... Click the link for more information.
''' Inclusive fitness is the sum of the direct and indirect fitness effects of an individual's behaviours, where the direct fitness effect is the impact on the individual's fitness, and the indirect fitness effect is the impact on the fitness of its social partners, weighted by
..... Click the link for more information.
..... Click the link for more information.
William Donald Hamilton, F.R.S. (1 August 1936 — 7 March 2000) was a British evolutionary biologist, considered one of the greatest evolutionary theorists of the 20th century.
..... Click the link for more information.
..... Click the link for more information.
Life history theory is an analytical framework widely used in animal and human biology, psychology, and evolutionary anthropology which postulates that many of the physiological traits and behaviors of individuals may be best understood in terms of the key maturational and
..... Click the link for more information.
..... Click the link for more information.
Robert L. Trivers, (born 19 February 1943, pronounced IPA: /ˈtrɪvɚz/) is an American evolutionary biologist and sociobiologist, most noted for proposing the theories of reciprocal altruism (1971), parental
..... Click the link for more information.
..... Click the link for more information.
Sex refers to the male and female duality of biology and reproduction. Unlike organisms that only have the ability to reproduce asexually, sexed male and female pairs have the ability to produce offspring through meiosis and fertilization.
..... Click the link for more information.
..... Click the link for more information.
Lactation describes the secretion of milk from the mammary glands, the process of providing that milk to the young, and the period of time that a mother lactates to feed her young.
..... Click the link for more information.
..... Click the link for more information.
mating is the pairing of opposite-sex or hermaphroditic internal fertilization animals for copulation and, in social animals, also to raise their offspring. Mating methods include random mating, disassortative mating, assortative mating, or a mating pool.
..... Click the link for more information.
..... Click the link for more information.
In biology, Bateman's principle is the theory that females almost always invest more energy into producing offspring than males, and therefore in most species females are a limiting resource over which the other sex will compete.
..... Click the link for more information.
..... Click the link for more information.
Sexual selection is the theory proposed by Charles Darwin that states that the frequency of traits can increase or decrease depending on the attractiveness of the bearer. Biologists today distinguish between "male to male combat" (it is usually males who fight), "mate choice"
..... Click the link for more information.
..... Click the link for more information.
Parent-offspring conflict is a term used to signify the evolutionary conflict arising from differences in optimal fitness of parents and their offspring. While parents tend to maximize the number of offspring, the offspring can increase their fitness by getting a greater share of
..... Click the link for more information.
..... Click the link for more information.
Female (♀) is the sex of an organism, or a part of an organism, which produces ova (egg cells). The ova are defined as the larger gametes in a heterogamous reproduction system, while the smaller, usually motile gamete, the spermatozoon is produced by the male.
..... Click the link for more information.
..... Click the link for more information.
Male (♂) refers to the sex of an organism, or part of an organism, which produces small mobile gametes, called spermatozoa. Each spermatozoon can fuse with a larger female gamete or ovum, in the process of fertilisation.
..... Click the link for more information.
..... Click the link for more information.
For the 1995 movie about hitmen, see .
Cold-blooded organisms maintain their body temperatures in ways different from mammals and birds. The term is now outdated in scientific contexts...... Click the link for more information.
Warm-blooded animals maintain thermal homeostasis; that is, they keep their body temperature at a constant level. This involves the ability to cool down or produce more body heat. Warm-blooded animals mainly control their body temperature by regulating their metabolic rates (e.g.
..... Click the link for more information.
..... Click the link for more information.
selection. Under selection, individuals with advantageous or "adaptive" traits tend to be more successful than their peers reproductively--meaning they contribute more offspring to the succeeding generation than others do.
..... Click the link for more information.
..... Click the link for more information.
William Donald Hamilton, F.R.S. (1 August 1936 — 7 March 2000) was a British evolutionary biologist, considered one of the greatest evolutionary theorists of the 20th century.
..... Click the link for more information.
..... Click the link for more information.
Robert L. Trivers, (born 19 February 1943, pronounced IPA: /ˈtrɪvɚz/) is an American evolutionary biologist and sociobiologist, most noted for proposing the theories of reciprocal altruism (1971), parental
..... Click the link for more information.
..... Click the link for more information.
David C. Geary is a notable United States cognitive developmental psychologist with interests in mathematical learning and in evolution. He is currently a Curators’ Professor in the Department of Psychological Sciences at the University of Missouri–Columbia.
..... Click the link for more information.
..... Click the link for more information.
David Buss (born April 14, 1953) is a professor of psychology at The University of Texas at Austin, known for his evolutionary psychology research on human sex differences in mate selection.
..... Click the link for more information.
..... Click the link for more information.
This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.
Herod_Archelaus
