Final Exam Terms Flashcards
Evolutionary Species Concept
species have a distinct evolutionary fate from other lineages
Phenetic Species Concept
Draws species boundaries between clusters
Biological Species Concept
pattern of gene flow, rather than phenetic similarity that determines species boundaries
Phylogenetic Species Concept
Uses shared derived traits to draw species boundaries between monophyletic groups.
Allopatric Speciation
speciation takes place in populations that are geographically isolated from one another
Parapatric Speciation
incipient species-diverging populations on the path to speciation-have distributions that abut one another
Sympatric Speciation
populations diverge into new species while in the same location
Dumbbell Model
an initially large population is subdivided into new populations that are themselves still relatively large ( less genetic drift )
Peripheral Isolate Model
populations that are geographically separated from one another differ in size, with one large population and one or more smaller populations (founder effects, accelerated genetic drift)
Cline
A spatial gradient in the frequency of phenotypes or genotypes
Hybrid Zone
diverging populations encounter each other, mate, and produce hybrid offspring
Reproductive Isolating Mechanisms
deter hybridization between two populations hybrids are at disadvantage usually but not always
Prezygotic Isolating Mechanisms
prevent or deter individuals from mating with one another, or prevent fertilization from occurring if such a mating does take place
Postzygotic Isolation Mechanisms
These operate after fertilization and conception, may lead to successful fertilization but the embryo does not survive. If it does, it may be fertile or have dramatically reduced fitness.
Cooperation
occurs when two or more individuals each receive a net benefit from joint actions
Inclusive Fitness
producing more offspring or helping her kin in reproductive endeavors
Direct Fitness
number of viable offspring reproduced
Indirect Fitness
incremental effect that the individual behavior has on the direct fitness of its genetic relatives
Eusociality
reproductive division of labor, only fraction of population mating at a given time
Reciprocal Altruism
individuals benefit from exchanging acts of altruism
Sexual Selection
depends on the advantage which certain individuals have over other individuals if the same sex and species in exclusive relation to reproduction
Monogomous Mating System
male and female mate with each other and only each other
Polygamous Mating System
either males or females have more than one mate
Polygyny
males mate with more than one female
Polyandry
females make with more than one male
Polygynandry
several males form pair bonds with several females simultaneously
Intersexual Selection
individuals of one sex select among individuals of the other sex as mates
Intrasexual Selection
in which members of one sex, most often males, compete with each other for mating access to the other sex
Runaway Sexual Selection Model
a gene that codes for a particular trait in males over time becomes associated with a gene that codes for a particular trait in males over time becomes associated with a gene that codes for a particular behavioral mating preference in females- linkage disequilibrium arises between alleles for male phenotype and female preference.
Postcopulatory Sexual Selection
competition occurring after female jas mated with numerous males
Sensory Bias Model
female nervous system responds to trait either because it is associated with some benefit outside of mate choice, or simply an artifact of how they are “wired”
Sexual Conflict
Traits that evolve in one sex may be detrimental to the other sex
