DOC PREVIEW
SC BIOL 301 - Social Behaviors

This preview shows page 1 out of 3 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 3 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 3 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

Biol 301 1nd Edition Lecture 11 Outline of Last Lecture I. ReproductionII. Sexual StrategiesIII. Sex DeterminationIV. Mating SystemsV. Sexual SelectionOutline of Current Lecture II. Social BehaviorsIII. Social Behavior TypesIV. Eusocial AnimalsCurrent LectureSocial behaviorso Social behaviors: interactions with members of one’s own species, including mates, offspring, other relatives, and unrelated individuals. Social behaviors have a genetic basis and are subject to natural selection. Selection has favored cohesive groups and constrained antagonism. Many organisms other than animals exhibit social behaviors.o Predator Detection/evasion: A group may be able to fend off predators better than an individual.o Dilution effect: the reduced, or diluted, probability of predation to a single animal when it isin a group. Probability of death = 1/group sizeo Vigilance-Group Size Effect: More individuals watching for predators allows each individual to spend less time watching, and more time feeding.o Food location: Many individuals searching for food may be able to find rare food more easily. Probability of prey capture may increase in a group.o Mate finding: Being social makes it easier to find potential mates because large groups attract the attention of females.o Lek: the location of an animal aggregation to put on a display to attract the opposite sex.o Conspicuousness: Groups of animals are more conspicuous to predators.o Disease Transmission: The risk of parasites increases in groups; high densities can increase the rate at which diseases spread. Risk of disease spread is particularly problematic in aquaculture or livestock operations, where animals are kept at high densities.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o Competition: Larger groups are better able to locate food, but that food must be shared among all members.o Aggression: Living in groups can lead to aggression among members.o Territory: any area defended by one or more individuals against the intrusion of others. Defending a high-quality territory generally assures greater resources (e.g., food, nest sites). Territories can be transient or relatively permanent. Territoriality common: mobile species, limited resources. Uncommon: high pop density, unpredictable resources (<benefits of group living)o Dominance hierarchy: a social ranking among individuals in a group, typically determined through contests such as fighting or other contests of strength or skill. Occurs when defending a territory is impractical; such as when conspecific density is high and it is not possible to defend against all of them. Once a hierarchy is established, contests are resolved quickly in favor of the first-ranked member. First-ranked members dominate all; second-ranked members dominate all but first-ranked, and so on. Saves Energy by decreasing duration of subsequent contestsTypes of social interactionso Donor: the individual who directs a behavior toward another individual as part of a social interaction.o Recipient: the individual who receives the behavior of a donor in a social interaction.o Every interaction between two individuals has the potential to affect the fitness of both individuals, either in a positive or negative way.o Cooperation: when the donor and the recipient of a social behavior both experience increased fitness from an interaction (e.g., when a herd of lions kill prey).o Selfishness: when the donor of a social behavior experiences increased fitness and the recipient experiences decreased fitness (e.g., competition for food).o Spitefulness: when a social interaction reduces the fitness of both donor and recipient (doesnot occur in natural populations).o Altruism: a social interaction that increases recipient fitness and decreases the fitness of thedonor. Altruism does not lead to direct fitness, which is the fitness an individual gains by passing on copies of its genes to its offspring. As a result, we would expect selfishness to prevail over altruism, yet altruism has evolved in many species.o Indirect fitness: the fitness than an individual gains by helping relatives (with which it sharesgenes through a common ancestor) pass on copies of their genes.o Inclusive fitness: the sum of direct fitness and indirect fitness.o Direct selection: selection that favors direct fitness.o Indirect selection (kin selection): selection favoring indirect fitness.o Coefficient of relatedness: the numerical probability of an individual and its relatives carrying copies of the same genes from a recent common ancestor.Eusocial Animalso Eusocial animals are distinguished by four characteristics:1. Several adults living together in a group2. Overlapping generations of parents and offspring living together in the same group3. Cooperation in nest building and brood care4. Reproductive dominance by one or a few individuals, and the presence of sterile individualso Among insects, eusocial species are limited to Hymenoptera and Isoptera, including bees, ants, wasps, and termites. Other than insects, the only two animals known to be eusocial are the naked mole rat and the Damaraland mole rat.o Caste: individuals within a social group sharing a specialized form of behavior.o Queen: the dominant, egg-laying female in eusocial insect societies; typically mate once during their lives. Sons are made by laying unfertilized eggs and daughters are made by laying fertilized eggs (i.e., a haplodiploid system).o Haplodiploid: a sex-determination system in which one sex is haploid and other sex is diploid. o Nonreproductive progeny of a queen gather food and care for developing brothers and sisters.o Societies include sterile, female workers; reproductive drones; and future queens.o Daughters are diploid and are produced when a queen’s haploid gamete is fertilized by a drone’s haploid gamete.o Drones (i.e., sons) are haploid and are produced when a queen’s gamete remains unfertilized.o Termite colonies can be massive structures dominated by a mated pair called the king and queen. The king and queen produce sons and daughters by sexual reproduction; both types of offspring serve as workers. Offspring remain sexually immature unless the king or queen dies. Many species have a cast of soldiers, which have very large heads and help to defend the nest.o Mole rats- A single queen and several kings are responsible for all reproduction.


View Full Document
Download Social Behaviors
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Social Behaviors and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Social Behaviors 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?