Exam 2 Flashcards
Ethology
study of how evolution influences behavior (in non-human animals)
psychology
study of human behavior
Tinbergen’s four questions
What stimulus elicits the behavior, and what mechanisms mediate the response?
How does the animal’s experience during growth and development influence the response?
How does the behavior aid survival and reproduction?
What is the behavior’s evolutionary history?
Types of animal behavior
Migration
Communication
Visual signals
Aural signals
Chemical signals
Tactile signals
Migration
long-range seasonal movement of animals.
Communication
Allows precise transfer of information between organisms
May represent a variety of different signals
Communication signals serve as stimuli for responses
Visual signals
Facial expressions
Dance-like movements
Aural signals
Vocalizations
Clapping/stomping/buzzing/etc.
Chemical signals
Pheromones
Signal sensed by organisms of same species
Tactile signals
Touch conveys meaning
Three types of migration
Obligate: Animals always migrate
Facultative migration: Animals choose to migrate or not migrate.
Incomplete migration: Some of the population migrates, while others do not.
Origin of a behavior
Behaviors may be innate or learned
Innate behaviors are a fixed feature of an organism’s function; do not require prior experience to operate
Learned behaviors require prior experience
Reflex action
an involuntary and rapid response to stimulus
Kinesis
the undirected movement in response to a stimulus
Taxis
the directed movement towards or away from a stimulus
Fixed action pattern
a series of movements elicited by a stimulus such that even when the stimulus is removed, the pattern goes on to completion
Imprinting
Limited opportunity for young to learn
Spatial
Landmarks are used to assist navigation
Associative
Cause-and-effect reasoning
Cognition
Creative problem solving
Social
Observing behavior of others; teaching
Heritability and behavior
Almost all behaviors have some genetic influence
Innate behaviors are most closely tied to genetic control
Evolutionary history of behavior
Heritable behaviors are subject to evolution in populations
Like coastal banana slug eaten only by coastal snakes
Sexual selection
selective pressures associated with mate choice
Individuals may compete with others of the same sex for access to mates
Physical contests are obvious and dramatic examples of such competition
Attractiveness also represents competition for access to mates
The economics of mate choice
If gametes are few in number and metabolically expensive, then the individual is benefited by choosing a mate of high quality
If gametes are plentiful and inexpensive, then the individual is benefited by having as many mates as possible
Mating systems (self-fertilization not shown)
Monogamy
Polygyny
Polyandry
Selfishness behavior
benefits the actor at the expense of others
Altruistic behavior
benefits others at the expense of the actor; self-sacrifice
Inclusive fitness influenced by reproductive efforts of individual as well as efforts of close kin
Kin selection theory predicts rise of altruistic behavior when close kin are benefactors of sacrifice
Eusociality
a social group dynamic in which only one or a few females reproduce and the rest provide parental care for the offspring (extreme altruism)
Naked mole rats, bees, etc
morphological species
states that members of a species exhibit similar anatomy and morphology
This applies well to fossils (not much else to go on), but frequently leads to incorrect conclusions
ecological species
states that members of a species share similar geographic range and ecological niche
This applies well to organisms when they are encountered under natural conditions, but is problematic when applied to organisms outside of their habitat
biological species
states that members of a species successfully interbreed to produce viable offspring under natural conditions (no reproductive isolation)
This applies well to animals, but is problematic when applied to bacteria (asexual) and fossils (poor evidence of reproduction)
4 types of prezygotic isolation
Temporal isolation – species have different breeding schedules
Habitat isolation – members of species select different habitats or are otherwise separated
Gametic isolation – Mechanical incompatibility prevents fertilization
Behavioral isolation – certain actions or behaviors (or the lack of them) impacts reproduction
2 types of postzygotic isolation
Hybrid inviability – an embryo is produced, but cannot survive development
Hybrid sterility – different species can produce a viable offspring, but that offspring cannot reproduce
Speciation can occur when:
Changes (mutations) over time lead to groups no longer being reproductively compatible
Geographic isolation may or may not play a role
The model of allopatric speciation
geographic isolation between members of a population
The geographic barrier prevents gene flow/causes reproductive isolation (you can say it either way) between the two parts of the population
Over time, the gene pools of each subpopulation will become more different from each other
Model of Sympatric Speciation
Speciation within the same physical location and conditions
May arise from genetic errors
May arise from behavioral variation
Autopolyploidy
Two or more complete sets of chromosomes in gametes. Results from error in cell division.
Allopolyploidy
Gametes from two different species combine
Hybridization
A hybrid has parents of different species
Some hybrids represent evolutionary dead-ends (hybrid inviability/sterility)
Some hybrids can survive and reproduce, but exhibit reduced fitness compared to genotypes of either parent species
Some hybrids (rarely) exhibit equal or greater fitness compared to either parent species
Hybrid zone
After speciation has occurred, the two separate but closely related species may continue to produce offspring in an area called the hybrid zone. Reinforcement, fusion, or stability may result, depending on reproductive barriers and the relative fitness of the hybrids.
