Flash Exam Flashcards
(47 cards)
symmetry
correspondence of size, shape of parts on opposite sides of median plane, like other features, has evolved
asymmetry
no symmetry, no planes divide into equal halves
spherical symmetry
•any plane through center divides body into mirrored halves
•suited for floating, rolling
•earth’s are aquatic
•some unicellular forms
•rare in animals
•protozoan—volvox
radial symmetry
(tire) divided into similar halves by 2 or more planes passing through longitudinal axis
biradial symmetry
•2 planes passing through longitudinal axis mirrored halves, usually sessile, freely floating, or weakly swimming animals
•no anterior or posterior end
sagittal plane
•two mirror portions (left and right)
•much better fitted for directional (forward) movement
cephalization
•concentration of nervous tissue & sense organs (head)
•advantageous to an animal moving through its environment head first
•most recent and successful
taxonomy
•formal system for naming & classifying species
•~1.5 million species of animals named
•probably less than 20% of extant animals and 1% of extinct
systematics
•broader science of classifying organisms based on similarity, biogeography, descent
•goals: to discover all species of animals, reconstruct their evolutionary relationships, to classify according to their evolutionary relationships
binomen
•Homo sapiens- “thinking man”
•Aedes albopictus- “white painted unpleasant”
3 domains
eukarya, achaea, bacteria
common descent
same pattern of ancestry
smallest distinct groupings
share patterns of ancestry and descent
reproductive community
•excluded members of other species distribution in space and time
•cosmopolitan: wide
•endemic: narrow
typological species concept
•pre-darwin, distinct, immutable entity
•a type specimen: labeled, deposited in a museum
•an ideal form- still have type specimen but variation is not considered deviation from type
biological species concept
•a species is a reproductive community of populations that occupies a specific niche in nature
•interbreeding central
•boundaries between species may be difficult to locate
•does not address asexual organisms
evolutionary species concept
•adds evolutionary time to the BSC
•a single lineage of ancestry-descendant populations that maintains its own identity from other such lineages and that has its own evolutionary tendencies and historical fate
•considers sexual, asexual, time
cohesion species concept
•the most inclusive population of individuals having the potential for phenotypic cohesion through intrinsic cohesion mechanisms
•definition includes genetic changes (gene flow, genetic drift, natural selection)
phylogenetic species concept
•an irreducible (basal) grouping of organisms diagnosable distinct from other such groupings & within which there is a parental pattern of ancestry and descent
•asexual, sexual
•phylogenetic species is the smallest single population lineage with no detectable branching
systematics major goal
•infer the evolutionary tree (phylogeny) that relates all extant & extinct species
•organismal features that vary among species
•common: morphological, chromosomal, molecular
•less common: behavioral, ecological
homology
•character similarly resulting from common ancestry
•similarity does not always reflect common ancestry
•fur in bats and mice
homoplasy
•character similarity that misrepresents common descent (wings)… birds, bats, insect
•wings in birds and bats, thumbs in primates and pandas
who proposed 3 domains
woese, kandler, and wheelis
who proposed 5-kingdom system
R.H. Whittaker
