48 terms


individuals do not evolve, these do
heritable change in line of descent
original source of new alleles
natural selection
can only occur in populations where there are selective pressures and differences in forms of heritable traits. survival of the fittest
stabilizing selection
eliminates uncommon forms of alleles, favors intermediates forms of a trait
Directional Selection
favors extreme forms of a trait
Disruptive Selection
favors extreme forms of traits, eliminates common forms of alleles
Sexual dimorphism
sexual selection, such as competition between males for access to fertile females, frequently influences aspects of body form leads to
Balanced polymorphism
persistence of the sickle allele at high frequency in a population
gene flow
tends to keep different populations of a species similar to one another, allele frequencies change owing to immigration, emigration or both
allopatric speciation
a fire devastates all trees in a wide swath of forest, populations of a tree dwelling frog on either side of the burned area diverge
genetic drift
change in a populations allele frequencies due to chance alone
adaptive radiation
burst of divergences from one lineage into a set of niches
leads to interdependent species
Homologous Structures
may differ in size shape and function in major groups of organisms, mutation may lead to major differences between adults of related lineages by altering steps in embryo development. human arm and bird wing
morphological divergence
a body part of an ancestor is modified differently in different lines of descent
amino acid sequence
some mutations are neutral because they don't affect...
mitochondrial dna
may be used in cladistic comparison of different species, individuals of the same species
molecular clocks
based on comparisons of the neutral mutations between species
based on character differences between species
in evolutionary trees each branch represents
Sister Groups
same age in cladograms
evolutionary history
sets within sets
homeotic genes
similar across diverse taxa
analogous structures
insect wing and bird wing
Big bang model
universe is continuing to expand
abundance of in atmosphere would have prevented the spontaneous assembly of organic cmpds
Stanley Miller
experiment illustrated that oxygen is necessary for life
Deep Sea vents
prevelance of iron sulfide cofactors in living organism that life may have arose near
protein formation
negatively charged clay particles played a role in
rna that acts as an enzyme
Heat from hydrothermal vents
certain pigments that evolved and were later used in photosynthesis may have originally helped cells detect..
noncyclic pathway
evolution of caused increase in oxygen levels
aerobic bacteria
mitochondria probably descendants of
one cells lives in another and becomes interdependent
dome shaped structure formed by mats of photosynthetic cells and sediments
first eukaryotes
dna or rna may be the genetic material of a
viroid consists entirely of, plasmid circle of
prokaryotic fission
how bacteriophages multiply
genetic material of hiv
bacteria transfer plasmids by
all are oxygen releasing phototrophs
ecoli cells that live in your gut are
all are intracellular parasites of vertebrates
formed by gram positive bacteria to survive harsh conditions
worldwide outbreak of a disease