Exam 4 Chapter 5
Terms
undefined, object
copy deck
- Classification
- in biology, the ordering of organisms into categories such as orders, families, and genera, to show evolutionary relationships.
- Metazoa
- multicellular animals, a major division of the animal kingdom.
- chordata
- the phylum of the animal kingdom that includes vertebrate.
- Vertebrates
- animals with segmented boney spinal columns, including fishes, amphibians, reptiles, birds and mammals.
- homologies
-
similarities between organisms based on descent from a common ancestor.
EX: the similarities in the forelimb bones of animals, explained by similar descent. - analogies
- similarities between organisms based strictly in common function with no assumed common evolutionary descent.
- Homoplasy
-
the separate evolutionary development if similar characteristics in different groups of organisms.
EX: similar function in the wings of butterflies and birds, but completely different anatomical features. - Evolutionary Systematics
- a traditional approach to classification in which presumed ancestors and descendants are traced in time by analysis of homologous charaters.
- Cladistics
- an approach to classification that attempts to make rigorous evolutionary interpretations based solelyon analysis of certain types of homologous characters (those considered to be derived characters).
- Ancestral (primitive)
- referring to characters inherited by a group of organisms from a remote ancestor and thus not diagnostic of groups [lineages] that diverged after the first appeared.
- clade
- a group of organisms sharing a common ancestor. the group includes the common ancestor and all descendants.
- derived (modified)
- referring to characters that are modified from the ancestral condition and thus are diagnostic of particular evolutionary lineages.
- phylogenetic tree
- a chart showing evolutionary relationships as determined by phylogenetic systematics. It contains a time component and implies ancestor descendant relationship.
- cladogram
- a chart showing evolutionary relationships as determined by cladestic analysis. it is based solely on interpretation of shared derived characters. no time component is inidcated, and ancestor-descendant relationships are not implied.
- biological species concept
- a depiction of species as groups of spcies as groups of individuals capable of fertile interbreeding, but reprodutively isolated from other such groups.
- speciation
- the process by which a new species evolves from a prior species. speciation is the most basic process in macroevolution.
- recognition species concept
- a depiction of species in which the key aspect is the ability of individuals to identify members of their own species for purposes of mating (and to avoid mating with members of other species). in theory, this type of selective mating is a component of a species concept emphasizing mating and is therefore compatible with the biological species concept.
- ecological species concept
- the concept that is a species is a group of organisms exploiting a single niche. this view emphasizes the role of natural selection in separating species from one another.
- allopatric
- living on different areas, important in the divergence of closely related species for each other and from their shared ancestral species because it leads to reproductive isolation.
- sexual dimorphism
- differences in physical characteristics between males and females of the same species. for eample, humans are slightly exually dimorphic for body size, with males being taller, on average, than females of the same population.
- intraspecific
- within species, refers to variation seen within the smae species.
- interspecific
- between species, refers to variation beyond that seen within the same species to include additional aspects seen between tow different species.
- paleospecies
- species defined from fossil evidence, often covering a long time span
- genus
- a group of closely related species.
- geological time scale
- the organization of earth history into eras, periods, and epochs, commonly used by geologists and paleoanthropologists.
- continent drift
- the movement of continents on sliding plates of the earth's surface. as a result, the positions of large landmasses have shifted dramatically during the earth's history.
- ecological niches
- the positions of species within their physical and biological environments, together making up the ecosystem. a species' ecological niche is defined by such components as diet, terrain, vegetation, type of predators, relationships with other species, and activity patterns, and each niche in unique to a given species.
- epochs
- categories of the geological time scale; subdivisions of periods. in the cenozoic, epochs include the paleocene, eocene, oligocene, miocene, and pliocene and the pleistocene and holocene.
- viviparous
- giving birth to live young.
- heterodont
- having different kinds of teeth; characteristic of mammals, whose teeth consist of incisors, canines, premolars, and molars.
- endothermic
- able to maintain internal body temperature through the production of energy by means of metabolic processes within cells, characteric of mammals, birds, and perhaps some dinosaurs.
- adaptive radiation
- the relatively rapid expansion and diversification of life forms into new ecological niches.
- punctuated equilibrium
- the concept that evolutionary change proceeds through long periods of stasis punctuated by rapid periods of change.