Biology Chapter 15: Tracing Evolutionary History – Flashcards
Unlock all answers in this set
Unlock answersquestion
stromatolite
answer
Layered rocks that result from the activities of prokaryotes that bind thin films of sediment together.
question
radiometric dating
answer
A method for determining the absolute ages of fossils and rocks, based on the half-life of radioactive isotopes.
question
geologic record
answer
A time scale established by geologists that divides Earth's history into time periods, grouped into three eons— Archaean, Proterozoic, and Phanerozoic— and further subdivided into eras, periods, and epochs.
question
plate tectonics
answer
The theory that the continents are part of great plates of Earth's crust that float on the hot, underlying portion of the mantle. Movements in the mantle cause the continents to move slowly over time.
question
Pangaea
answer
The supercontinent consisting of all the major landmasses of Earth fused together. Continental drift formed Pangaea near the end of the Paleozoic era.
question
paedomorphosis
answer
The retention in an adult of juvenile features of its evolutionary ancestors.
question
phylogeny
answer
The evolutionary history of a species or group of related species.
question
convergent evolution
answer
Adaptive change resulting in nonhomologous (analogous) similarities among organisms. Species from different evolutionary lineages come to resemble each as a result of living in very similar environments.
question
analogy
answer
The similarity between two species that is due to convergent evolution rather than to descent from a common ancestor with the same trait.
question
systematics
answer
A scientific discipline focused on classifying organisms and determining their evolutionary relationships.
question
taxonomy
answer
The branch of biology that identifies, names, and classifies species.
question
binomial
answer
A two-part, Latinized name of a species; for example, Homo sapiens.
question
genus
answer
(plural, genera) In classification, the taxonomic category above species; the first part of a species' binomial; for example, Homo.
question
family
answer
In classification, the taxonomic category above genus.
question
order
answer
In classification, the taxonomic category above family.
question
class
answer
In classification, the taxonomic category above order.
question
phyla
answer
In classification, the taxonomic category above class.
question
kingdom
answer
In classification, the broad taxonomic category above phylum.
question
domain
answer
A taxonomic category above the kingdom level. The three domains of life are Archaea, Bacteria, and Eukarya.
question
taxon
answer
A named taxonomic unit at any given level of classification.
question
phylogenetic tree
answer
A branching diagram that represents a hypothesis about the evolutionary history of a group of organisms.
question
cladistics
answer
An approach to systematics in which common descent is the primary criterion used to classify organisms by placing them into groups called clades.
question
clade
answer
A group of species that includes an ancestral species and all its descendants.
question
monophyletic
answer
Pertaining to a taxon derived from a single ancestral species that gave rise to no species in any other taxa.
question
shared ancestral character
answer
A character, shared by members of a particular clade, that originated in an ancestor that is not a member of that clade.
question
shared derived character
answer
An evolutionary novelty that is unique to a particular clade.
question
outgroup
answer
In a cladistic study of evolutionary relationships among taxa of organisms, a taxon or group of taxa known to have diverged before the lineage that contains the group of species being studied.
question
ingroup
answer
In a cladistic study of evolutionary relationships among taxa of organisms, the group of taxa that is actually being analyzed.
question
parsimony
answer
In scientific studies, the search for the least complex explanation for an observed phenomenon.
question
molecular systematics
answer
A scientific discipline that uses nucleic acids or other molecules in different species to infer evolutionary relationships.
question
molecular clock
answer
Evolutionary timing method based on the observation that at least some regions of genomes evolve at constant rates.
question
three-domain system
answer
The branch of biology that identifies, names, and classifies species.
question
horizontal gene transfer
answer
The transfer of genes from one genome to another through mechanisms such as transposable elements, plasmid exchange, viral activity, and perhaps, fusions of different organisms.
