-
Contingency Theory
A mathematical model to determine when an animal should eat a less profitable, but more abundant food and when the animal should pass this food up in search of a more profitable, but scarce food. Contingency Theory states that you should eat the less profitable food 2 if: E2/h2 > E1/(h1 + s1)
-
Degree of relatedness
The probability of two individuals sharing identical genes by descent.
-
Diploid
Having two copies of every chromosome, one from each parent.
-
Direct fitness
The number of offspring an individual produces.
-
Eusocial
A social strategy marked by a reproductive division of labor, cooperative rearing of young, and overlapping generations.
-
Evolutionarily Stable Strategy
A strategy such that if all members of a population follow the rules, no other strategy could invade the population through natural selection.
-
Fitness
A nonspecific term usually referring to direct fitness.
-
Frequency-dependent selection
A form of natural selection in which the fitness of an individual's genes is dependent upon the relative frequency of that gene in the population.
-
Games
An interaction between two players with a conflict of interest.
-
Haplodiploid
A reproductive system in which females are diploid and males result from unfertilized, haploid eggs.
-
Haploid
Having only one set of chromosomes, usually by meiosis, or resulting from an unfertilized eggs.
-
Inclusive fitness
The sum of direct fitness and indirect fitness.
-
Indirect fitness
The number of relatives produced multiplied by the degree of relatedness to those individuals.
-
Intersexual selection
A form of sexual selection in which members of one sex are differentially attracted to members of the opposite sex, and so competition is for the attention of the opposite sex.
-
Intrasexual selection
A form of sexual selection in which members of one sex compete with each other to mate with the opposite sex. Males will frequently fight each other for a female or for a desirable territory to attract a female.
-
Marginal value theory
A mathematical model to analyze when an animal should leave a food patch in search of another, fresher patch. Reminiscent of the economic principle of the law of diminishing returns.
-
Meiosis
Cell division from one cell into four cells during two separate divisions. The result are haploid cells.
-
Mitosis
Cell division from one cell into two. Resultant daughter cells have the same number of chromosomes as the parent cell.
-
Monogamy
A mating strategy in which two individuals from a permanent pair-bond. Most cases are actually behavioral monogamy where males contribute to parenting and protection, but both sexes may engage in extra-pair copulations.
-
Optimality
Behavior analyzed in terms analogous to economic decision making.
-
Operational Sex Ration (OSR)
The Operational sex ratio is the ratio of sexually available females to ready males.
-
Parthenogenesis
Asexual reproduction. Literally "virgin origin".
-
Polyandrous
A mating system in which females mate multiple males.
-
Polygamous
Describes individuals engaged in a mating system where individuals (of either sex) have multiple mates.
-
Polygyny
A mating system in which males mate several females.
-
Polymorphic
The coexistence of two or more traits within a species. For example, eye color and blood type are polymorphic.
-
Profitability
The amount of energy yielded by a food source divided by the amount of time spent handling it once it is found. P=E/h
-
Promiscuous
Promiscuity is a mating system in which individuals of both sexes mate with multiple individuals, a combination of polygyny and polyandry.
-
Resource defense polygyny
A mating strategy in which males arrive at breeding sites early to fight over desirable territories. Females arrive at the breeding site and choose males based on their occupied territories.
-
Sexual selection
A form of natural selection in which individuals have differential reproductive success based on competition for mates.
-
Spermatophore
A bundle of sperm and proteinaceous material presented to female insect as a nuptial gift.
-
Strategies
The rules describing the behavior an animal may engage in while engaged in games. The Proportion of the population employing two different strategies: p+q=1, or p(Q) + q(R) = p(S) + q(T).
-
Syngamy
The fusion of egg and sperm cells into a zygote.