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Trivers
Robert Ludlow "Bob" Trivers (; born February 19, 1943) is an American evolutionary biologist and sociobiologist. Trivers proposed the theories of reciprocal altruism (1971), parental investment (1972), facultative sex ratio determination (1973), and parent–offspring conflict (1974). He has also contributed by explaining self-deception as an adaptive evolutionary strategy (first described in 1976) and discussing intragenomic conflict. Education Trivers studied evolutionary theory with Ernst Mayr and William Drury at Harvard from 1968 to 1972, when he earned his PhD in biology. At Harvard he published a series of some of the most influential and highly cited papers in evolutionary biology. His first major paper as a graduate student was "The evolution of reciprocal altruism", published in 1971. In this paper Trivers offers a solution to the longstanding problem of cooperation among unrelated individuals and by doing so overcame a crucial problem for how to police the system by ...
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Parental Investment
Parental investment, in evolutionary biology and evolutionary psychology, is any parental expenditure (e.g. time, energy, resources) that benefits offspring.Clutton-Brock, T.H. 1991. ''The Evolution of Parental Care''. Princeton, NJ: Princeton U. Press. pg. 9Trivers, 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. . Parental investment may be performed by both males and females (biparental care), females alone (exclusive maternal care) or males alone (exclusive paternal care). Care can be provided at any stage of the offspring's life, from pre-natal (e.g. egg guarding and incubation in birds, and placental nourishment in mammals) to post-natal (e.g. food provisioning and protection of offspring). Parental investment theory, a term coined by Robert Trivers in 1972, predicts that the sex that invests more in its offspring will be more selective when choosi ...
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Self-deception
Self-deception is a process of denying or rationalizing away the relevance, significance, or importance of opposing evidence and logical argument. Self-deception involves convincing oneself of a truth (or lack of truth) so that one does not reveal any self-knowledge of the deception. Brief history While Freudian analysis of the conscious and the unconscious minds dominated the field, psychological scientists in the 1970s became curious about how those two seemingly separate worlds could work together. The lack of mechanistic models available to this line of research, led to the debate being unresolved. Later, the focus has been shifted to vision-related research in social psychology. Theorization Analysis The traditional paradigm of self-deception is modeled after ''interpersonal'' deception, where ''A'' intentionally gets ''B'' to believe some proposition ''p'', all the while knowing or believing truly ¬''p'' (not ''p''). Such deception is intentional and requires the decei ...
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Trivers–Willard Hypothesis
In evolutionary biology and evolutionary psychology, the Trivers–Willard hypothesis, formally proposed by Robert Trivers and Dan Willard in 1973, suggests that female mammals adjust the sex ratio of offspring in response to maternal condition, so as to maximize their reproductive success ( fitness). For example, it may predict greater parental investment in males by parents in "good conditions" and greater investment in females by parents in "poor conditions" (relative to parents in good conditions). The reasoning for this prediction is as follows: Assume that parents have information on the sex of their offspring and can influence their survival differentially. While selection pressures exist to maintain a sex ratio of 50, evolution will favor local deviations from this if one sex has a likely greater reproductive payoff than is usual. Trivers and Willard also identified a circumstance in which reproducing individuals might experience deviations from expected offspring reproduc ...
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Reciprocal Altruism
In evolutionary biology, reciprocal altruism is a behaviour whereby an organism acts in a manner that temporarily reduces its fitness while increasing another organism's fitness, with the expectation that the other organism will act in a similar manner at a later time. The concept was initially developed by Robert Trivers to explain the evolution of cooperation as instances of mutually altruistic acts. The concept is close to the strategy of "tit for tat" used in game theory. In 1987 Trivers told a symposium on reciprocity that he had originally submitted his article under the title "The Evolution of Delayed Return Altruism", but reviewer W. D. Hamilton suggested that he change the title to "The Evolution of Reciprocal Altruism". Trivers changed the title, but not the examples in the manuscript, which has led to confusion about what were appropriate examples of reciprocal altruism for the last 50 years. In their contribution to that symposium, Rothstein and Pierotti (1988) ad ...
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Parent–offspring Conflict
Parent–offspring conflict (POC) is an expression coined in 1974 by Robert Trivers. It is used to describe the evolutionary conflict arising from differences in optimal parental investment (PI) in an offspring from the standpoint of the parent and the offspring. PI is any investment by the parent in an individual offspring that decreases the parent's ability to invest in other offspring, while the selected offspring's chance of surviving increases. POC occurs in sexually reproducing species and is based on a genetic conflict: Parents are equally related to each of their offspring and are therefore expected to equalize their investment among them. Offspring are only half or less related to their siblings (and fully related to themselves), so they try to get more PI than the parents intended to provide even at their siblings' disadvantage. However, POC is limited by the close genetic relationship between parent and offspring: If an offspring obtains additional PI at the expense of ...
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Sex Ratio
The sex ratio (or gender ratio) is usually defined as the ratio of males to females in a population. As explained by Fisher's principle, for evolutionary reasons this is typically about 1:1 in species which reproduce sexually. Many species deviate from an even sex ratio, either periodically or permanently. Examples include parthenogenic species, periodically mating organisms such as aphids, some eusocial wasps, bees, ants, and termites. The human sex ratio is of particular interest to anthropologists and demographers. In human societies, sex ratios at birth may be considerably skewed by factors such as the age of mother at birth and by sex-selective abortion and infanticide. Exposure to pesticides and other environmental contaminants may be a significant contributing factor as well. As of 2014, the global sex ratio at birth is estimated at 107 boys to 100 girls (1,000 boys per 934 girls).. Types In most species, the sex ratio varies according to the age profile of the populat ...
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Richard Dawkins
Richard Dawkins (born 26 March 1941) is a British evolutionary biologist and author. He is an emeritus fellow of New College, Oxford and was Professor for Public Understanding of Science in the University of Oxford from 1995 to 2008. An atheist, he is well known for his criticism of creationism and intelligent design. Dawkins first came to prominence with his 1976 book ''The Selfish Gene'', which popularised the gene-centred view of evolution and introduced the term '' meme''. With his book ''The Extended Phenotype'' (1982), he introduced into evolutionary biology the influential concept that the phenotypic effects of a gene are not necessarily limited to an organism's body, but can stretch far into the environment, for example, when a beaver builds a dam. His 2004 The Ancestor's Tale set out to make understanding evolution simple for the general public, by tracing common ancestors back from humans to the origins of life. Over time, numerous religious people challenged th ...
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Intragenomic Conflict
Intragenomic conflict refers to the evolutionary phenomenon where genes have phenotypic effects that promote their own transmission in detriment of the transmission of other genes that reside in the same genome. The selfish gene theory postulates that natural selection will increase the frequency of those genes whose phenotypic effects cause their transmission to new organisms, and most genes achieve this by cooperating with other genes in the same genome to build an organism capable of reproducing and/or helping kin to reproduce. The assumption of the prevalence of intragenomic cooperation underlies the organism-centered concept of inclusive fitness. However, conflict among genes in the same genome may arise both in events related to reproduction (a selfish gene may "cheat" and increase its own presence in gametes or offspring above the expected according to fair Mendelian segregation and fair gametogenesis) and altruism (genes in the same genome may disagree on how to value ot ...
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Jon Seger
Jon Allen Seger is an American evolutionary ecologist, and Distinguished Professor of Biology at the University of Utah. He helped develop the theory of bet-hedging in biology. His work has appeared in leading scientific journals such as ''Nature'', ''Science'', ''Nature Genetics'', ''Molecular Biology and Evolution'', ''Journal of Evolutionary Biology'', as well as popular magazines such as ''Scientific American''. Biography Dr. Seger attended UC Santa Barbara for his undergraduate studies, where he received a B.A. in English in 1969. Following college, he worked at the National Museum of Natural History on an assignment to help the museum establish public environmental education programs. He then enrolled at Harvard University, where he received his EdM in 1972 and his PhD in Biology in 1980. Much of his early work concerned models of sex ratio evolution and a variety of social insects (such as the Vespidae wasps). This work often took the form of mathematical models built from ' ...
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Steven Pinker
Steven Arthur Pinker (born September 18, 1954) is a Canadian-American cognitive psychologist, psycholinguist, popular science author, and public intellectual. He is an advocate of evolutionary psychology and the computational theory of mind. Pinker is the Johnstone Family Professor of Psychology at Harvard University, and his academic specializations are visual cognition and developmental linguistics. His experimental subjects include mental imagery, shape recognition, visual attention, children's language development, regular and irregular phenomena in language, the neural bases of words and grammar, as well as the psychology of cooperation and communication, including euphemism, innuendo, emotional expression, and common knowledge. He has written two technical books that proposed a general theory of language acquisition and applied it to children's learning of verbs. In particular, his work with Alan Prince published in 1989 critiqued the connectionist model of how children ac ...
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Crafoord Prize
The Crafoord Prize is an annual science prize established in 1980 by Holger Crafoord, a Swedish industrialist, and his wife Anna-Greta Crafoord. The Prize is awarded in partnership between the Royal Swedish Academy of Sciences and the Crafoord Foundation in Lund. The Academy is responsible for selecting the Crafoord Laureates. The prize is awarded in four categories: astronomy and mathematics; Geology, geosciences; Biology, biosciences, with particular emphasis on ecology; and polyarthritis, the disease from which Holger severely suffered in his last years. According to the Academy, "these disciplines are chosen so as to complement those for which the Nobel Prizes are awarded". Only one award is given each year, according to a rotating scheme – astronomy and mathematics; then geosciences; then biosciences. A Crafoord Prize in polyarthritis is only awarded when a special committee decides that substantial progress in the field has been made. The recipient of the Crafoord Prize is a ...
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Sociobiologist
Sociobiology is a field of biology that aims to examine and explain social behavior in terms of evolution. It draws from disciplines including psychology, ethology, anthropology, evolution, zoology, archaeology, and population genetics. Within the study of human societies, sociobiology is closely allied to evolutionary anthropology, human behavioral ecology, evolutionary psychology, and sociology. Sociobiology investigates social behaviors such as mating patterns, territorial fights, pack hunting, and the hive society of social insects. It argues that just as selection pressure led to animals evolving useful ways of interacting with the natural environment, so also it led to the genetic evolution of advantageous social behavior. While the term "sociobiology" originated at least as early as the 1940s, the concept did not gain major recognition until the publication of E. O. Wilson's book '' Sociobiology: The New Synthesis'' in 1975. The new field quickly became the subject ...
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