Bio Ch 19 Flashcards
Systematic biology (systematics)
study of the history of biodiversity; quantitative science that uses characteristics of living and fossil organisms (traits) to infer the relationships among organisms over time
Traits
characteristics of living and fossil organisms
Taxonomy
branch of systematic biology that identifies, names, and organizes biodiversity into related categories
Taxon (pl. taxa)
general name for a group of organisms that exhibit a set of shared traits
Classification
process of naming and assigning organisms or groups of organisms to a taxon
Taxonomists
scientists that study taxonomy; strive to classify all living things on Earth
Natural Groups
groupings of organisms that represent a shared evolutionary history; classified by using a set of traits to construct a phylogeny
Phylogeny
evolutionary family tree; represents the evolutionary history of taxa; classifies taxa based on shared ancestry
Binomial nomenclature
developed by Linnaeus; part of his classification system in which each species receives a unique 2-part Latin name
Specific epithet
2nd word in binomial nomenclature; refers to a species within the genus (which is the 1st word)
Species, genus, family, order, class, phylum, kingdom, domain
major taxonomic groups
Nomenclature
procedure of assigning scientific names to taxonomic groups
5-Kingdom System
1969, RH Whittaker expanded the classification system to this, which includes Monera, Protista, Fungi, Plantae, & Animalia; organisms were placed in these kingdoms based on type of cell (prokaryotic vs. eukaryotic), complexity (unicellular or multicellular), and type of nutrition
Domain Bacteria, Domain Archaea, & Domain Eukarya
1970 - Carl Woese proposed 2 groups of prokaryotes and that they should be assigned to a classification higher than kingdom
Common Ancestor
an ancestor to 2 or more lines of descent
Lineage
each branch in a phylogeny; represents a descendant of a common ancestor
Diverge
when a new character evolves, a new evolutionary path can begin from the old; a new lineage is formed, and a new branch of the phylogeny arises
Ancestral Traits
those traits found in the common ancestor; not useful for determining the evolutionary relationships of an ancestor’s descendants
Derived Traits
those traits not found in the common ancestor of a taxonomic group; most important traits for clarifying evolutionary relationships
Cladistics
method that uses shared, derived traits to develop a hypothesis of evolutionary history
Cladogram
the evolutionary history of derived traits is interpreted into a type of phylogeny constructed with cladistic methods
Clade
a common ancestor and all of its descendant lineages
Parsimony
cladistics applies this principle to a set of traits to construct a cladogram; considers the simplest solution to be the “optimal” solution
Outgroup
taxon used to determine the ancestral and derived states of characters in the ingroup
Ingroup
taxa for which the evolutionary relationships are being determined
Chordates
all of these have a dorsal or spinal nerve chord
Homology
structural similarity that stems from having a common ancestor
Homologous Structures
structures similar to each other because of common descent
Convergent Evolution
has occurred when distantly related species have a structure that looks the same only because of adaptation to the same type of environment
Analogy
similarity due to convergence; example: wings of an insect and the wings of a bat
Analogous Structures
structures that have the same function in different groups but do not have a common ancestry
Molecular clock
neutral mutations can be used as this to construct a timeline of evolutionary history
