phylogeny
evolutionary history showing the relatedness of a group
taxa
any groups of organisms
node
point where branch splits + common ancestor from which descendent species diverged
phylogenetic tree
shows evolutionary history of groups and organinsms
classification
reflects understanding of phylogenetic relationships
clade '(monophyletic)
group of organisms that include a common ancestor and all its descendants
sauropids
group of birds and traditional reptiles
paraphyletic
includes some but not all of descendants of a common ancestor
cladogram
type of evolutionary tree based on clades
characters
anatomical, physiological, or molecular features that makeup organisms
shared characters
characters sometimes present in two or more groups of organisms
homology
similarity that results from shared ancestry
analogy
similarity that results from convergent evolution
echolocation
to locate objects in their surroundings by emitting sounds and interpreting patterns of echoes
prestin
hair cells of mammalian ars and is involved in hearing ultrasonic frequencies
derivable character
evolutionary innovation in ancestors of horses and donkeys
synapomorphy
novelty arises in common ancestor of two taxa
outgroup
taxon whose common ancestor with the group of interest is older than common ancestor of group interest
molecular data
provides wealth of characters that complement other types of info. in building tree
biological species concept (BSC)
species are groups of actually or potentially interbreeding populations that are reproductively isolated from each other such groups
morphospecies
members of the same species usually look alike
niche
complete description role the species plays in their environment and of its abiotic and biotic environments
reproductive isolation
inability of diff species to produce viable, fertile offspring
prezygotic
factors act before fertilization + prevent fertilization
postzygotic
after fertilization + prevent fertilzed egg from devloping
speciation
process by which new species are produced
divergent evolution
2 pop. of organisms become genetically and physically diff from each other
allopatric
populations geographically separated from each other
dispersal
some individuals colonize a distant place
vicariance
geographic barrier arises within single pop. separating it into 2 or more isolated pop.
sympatric
pop. that are in the same geographic location
adaptive radiation
unusually rapid evolutionary diversification in which natural selection accelerates the rates of both speciation and adaptation
gradualism
species change slowly over time
punctuated equilibrium
model in which there are periods if relatively little change