Evolution
Biology 201 with Vandermast at University of Chapel Hill
About this deck
By: Brittney Akpobiyeri
Textbook:
Ecology, Second Edition
Evolutionary Analysis
Created: 2011-05-11
Size: 60 flashcards
Views: 60
Textbook:
Ecology, Second Edition Evolutionary AnalysisCreated: 2011-05-11
Size: 60 flashcards
Views: 60
About StudyBlue
STUDYBLUE makes things that make you better at school.
Things like online flashcards with photos and audio.
Things like personalized quizzes and friendly reminders about when (and what) to study next.
Think of it as a digital backpack™: access to all of your study materials online and on your phone.
STUDYBLUE exists to make studying efficient and effective for every student, for free. Join us.
“Simply amazing. The flash cards are smooth, there are many different types of studying tools, and there is a great search engine. I praise you on the awesomeness.”
Dennis
Dennis
Sign up (free) to study this.
Darwinian fitness
the ability of an individual to survive and reproduce in its environment
adaptation
a trait or characteristic of an organism that increases its fitness relative to individuals without the trait
heritability
the proportion of the variation observed in a population that is due to variation in genes
blending inheritance
the hypothesis that heritable factors blend to produce a phenotype and are passed on to offspring in this blended form
sexual selection
differential reproductive success due to variaton among individuals in success at getting mates
natural selection
differential reproductive sucess due to variation among individuals in survival and reproduction
parental investment
energy and time expended both in constructing an offspring and in caring for it
intrasexual selection
the key event that determines reproductive success (fighting) involves interactions among the members of a single sex
intersexual selection
the key event that determines reproductive success (choosing) involves an interaction between members of the two sexes
point mutation
alters a single point in the base sequence of a gene
transition and transversion
transition:
when a purine is substituted for the other purine (A or G) or pyrimidine is substituted for the other pyrimidine (T or C)
transversion:
when a purine is substituted for a pyrimidine or a pyrimidine is substituted for a purine
replacement substitutions
point mutations that result in an amino acid change
silent site substitutions
point mutations that result in no amino acid change
paralogous genes
genes that are duplicated and then diverge in sequence
orthologous genes
genes that are homologous but have diverged after a speciation event
population genetics
integrates Darwin's Theory of Evolution by Natural Selection with Mendelian genetics
population
a group of interbreeding individuals and their offspring
genetic drift
change in the frequencies of alleles in a population resulting from sampling error in drawing gametes from the gene pool to make zygotes and from chance variation in the survival and/or reproductive success of individuals; results in nonadaptive evolution
Hardy-Weinberg assumptions
There is no selection
There is no mutation
There is no migration
There are no chance events
Individuals choose their mates at random
Hardy-Weinberg equilibrium
a situation in which allele and genotype frequencies in an ideal population do not change from one generation to the next, because the population experiences no selection, no mutation, no migration, no genetic drift, and random mating
selection
when individuals with particular phenotypes survive to reproductive age at higher rates than individuals with other phenotypes, or when indiviuals with particular phenotypes produce more offspring during reproduction than individuals with other phenotypes
heterozygote superiority (overdominance)
heterozygotes have higher fitness than either homozygote
underdominance
describes a situation in which heterozygotes at a particular locus tend to have lower fitness than homozygotes
frequency-dependent selection
occurs when an individual's fitness depends on the frequency of its phenotype in the population; typically occurs when a phenotype has higher fitness when it is rare and lower fitness when it is common
mutation-selection balance
describes an equilibrium in the frequency of an allele that occurs because new copies of the allele are created by mutation at exactly the same rate that old copies of the allele are eliminated by natural selection
migration
the movement of alleles between populations; migration means "gene flow"
gene flow: the transfer of alleles from the gene pool of one populaton to the gene pool of another population
sampling error
a chance difference between the frequency of a trait in a subset of individuals from a population versus the frequency of the trait in the entire population. Sampling error is larger for small spamples than for large ones.
founder effect
a change in allele frequencies that occurs after a founder event, due to genetic drift in the form of sampling error in drawing founders from the source population
heterozygosity
the frequency of heterozygotes in a population
neutral theory
advantageous mutations are exceedingly rare and that most alleles of most genes are selectively neutral
selectionist theory
advantageous mutations are common enought that they cannot be ignored
polymorphisms
allele differences within species
hitchhiking (selective sweep)
occurs when strong positive selection acts on a particular amino acid change
inbreeding
mating among genetic relatives
coefficient of inbreeding (F)
the probability that the two alleles in an individual are identical by descent; both alleles came from the same ancestor allele in some previous generation
inbreeding depression
results from the exposure of deleterious recessive alleles to selection; refers to the effect these alleles have on the average fitness of offspring in the population
heritability
the fraction of the total variation in a trait that is due to variation in genes; always a number between 0 and 1
phenotypic variatoin
the total variation in a trait; symbolized by VP
genetic variation
variation among individuals that is due to variation in their genes; symbolized by VG
environmental variation
variation among individuals due to variatoin in their environments; symbolized by VE
additive genetic variation
variation among individuals due to the additive effects of genes (VA)
dominance genetic variation
variation among individuals due to gene interactions such as dominance (VD)
phylogeny
the evolutionary history of a group of species
phylogenetic tree
a graphical summary of the evolutionary history of a group of species
synapomorphy
homologous trait that is shared among certain species and is similar because it was modified in a common ancestor
cladogram
a phylogenetic tree inferred by clustering synapomorphies
convergent evolution
similarity between species that is caused by a similar, but evolutionarily independent, response to a common environmental problem
homoplasy
similarity in the characters found in different species that is due to convergent evolution, parallelism, or reversal, not common descent
bootstrapping
a technique for evaluating which branches on a particular tree are more well-supported than others
cladistic approaches
naming schemes that are based on evolutionary relationships
monophyletic groups
include all decendants of a common ancestor
paraphyletic groups
include some but not all descendants of a common ancestor
cryptic species
species that are indistinguishable morphologically, but divergent in songs, calls, odor, or other traits
allopatric model
hypothesis that speciation occurs when populations become geographically isolated and diverge because selection and drift act on them independently
vicariance
splitting of a population's former range into two or more isolated patches
secondary contact
when two populations that have diverged in isolation from a common ancestor are reunited geographically
reinforcement
selection that reduces the frequency of hybrids
prezygotic isolation
reproductive isolation between populatoins caused by differences in mate choice or timing of breeding, so that no hybrid zygotes are formed
postzygotic isolation
reproductive isolation between populations caused by dysfunctional developmnet or sterility in hybrid forms
hybrid zone
region where interbreeding between diverged populations occurs and hybrid offspring are frequent
About this deck
By: Brittney Akpobiyeri
Textbook: Ecology, Second Edition
Evolutionary Analysis
Created: 2011-05-11
Size: 60 flashcards
Views: 60
Textbook:
Ecology, Second Edition Evolutionary AnalysisCreated: 2011-05-11
Size: 60 flashcards
Views: 60
About StudyBlue
STUDYBLUE makes things that make you better at school.
Things like online flashcards with photos and audio.
Things like personalized quizzes and friendly reminders about when (and what) to study next.
Think of it as a digital backpack™: access to all of your study materials online and on your phone.
STUDYBLUE exists to make studying efficient and effective for every student, for free. Join us.
“Simply amazing. The flash cards are smooth, there are many different types of studying tools, and there is a great search engine. I praise you on the awesomeness.”
Dennis
Dennis