Chapter 1: Introduction Flashcards
Analogous
Structures in two or more organisms that perform a similar function but the similarity is not the result of descent from a common ancestor.
Ancestral
Of, or pertaining to, or inherited from, a common ancestor.
Apomorphy
In cladistics, a derived character state, modified from the ancestral state.
Biodiversity
The variety of living organisms considered at all levels in all habitats and ecosystems.
Camera Trap
A noninvasive capture technique that uses a camera placed in a field location to remotely photograph wild animals.
Character States
One of two or more alternative forms of a character. For example, incisor enamel (a character) with no pigmentation, slight orange pigmentation, or heavy brown pigmentation (character states).
Characters
A feature of an organism that can be described, measured, or effectively communicated between scientists. For example, pigmentation of incisor enamel.
Citizen Science
The collection of scientific data by interested members of the public (as volunteers) or students for the public good. Such projects when mammal-related often pertain to issues of ecological restoration, conservation, natural resource management, or wildlife monitoring.
Clade
A group of species or higher taxa consisting of a single common ancestor and all its descendants.
Cladist
A person who practices the cladistic approach to phylogenetic reconstruction.
Cladistics
A method od reconstructing a phylogeneitic hypothesis that is based on grouping taxa solely by their shared derived character states.
Cladogram
A branching diagram that illustrates hypothetical relationships between taxa and shows the evolution of lineages of organisms that have diverged from a common ancestor.
Convergence
The evolution of similar characteristics for similar functions in unrelated animals as a result of adaptation to similar environmental conditions or natural selection pressures.
Crown Group
Term used in phylogeny reconstruction to designate the smallest monophyletic group of organisms that includes the last common ancestor of all extant members of the group, and all of that ancestor’s descendants. An example within mammals is Rodentia, which includes all living rodents and fossil rodents that are descended from the hypothetical ancestor of Rodentia.
Cryptic Species
Biological species that are morphologically indistinguishable, but are genetically and reproductively distinct.
Derived
Refers to a character state that is a modified version of, and differs from, that in the ancestral stock.
Geochronological
The measurement of geological time as recorded in the Earth’s rock layers.
Homologous
Pertaining to structures or properties having a similar phylogenetic origin but not necessarily retaining a similar function, behavior, or identical structure.
Homoplasy
A similarity in a character in two different species that arises from evolutionary convergence or parallelism, not from common ancestry.
Ingroup
A group of organisms that is under cladistic analysis; a set of taxa that are presumed to be more closely related to one another than any is to an outgroup.
Molecular Clock
A hypothetical means of measuring evolutionary time that is based in the assumption that the rate at which mutational changes accumulate is relatively constant over time and therefore the changes are useful for dating the divergence of lineages. Also, a self-sustaining, autonomous, genetically regulated timekeeper within the hypothalamus of the brain that can be adjusted by daylight as sensed by the retina and perhaps by other environmental cues.
Molecular Phylogeny
A hypothetical representation of the evolutionary history of a group of organisms based on characters defined at the molecular level.
Monophyletic
Refers to a group of organisms whose members are all descended from (and including) a common ancestor.
Nodes
Refers to the place on a cladogram where two lineages diverge.
Outgroup
In phylogeny reconstruction, a group used for comparison that is related to but not part of the group under study.
Parallelism
Evolutionary change in two or more related lineages such that the corresponding features undergo equivalent alterations.
Phylogenetic Relationship
see Phylogeny.
Phylogeny
The evolutionary history of an organism or group of organisms with respect to ancestor-descendant relationships; also, a hypothesis graphically describing such relationships, usually in a treelike or bushlike diagram.
Plesiomorphy
A character state that is ancestral for the organism under study.
Polarity
The direction of evolutionary transformation in a phylogenetic character.
Sister Group
In a phylogeny, the monophyletic group most closely related to a monophyletic group under study. One of two clades that resulted from the splitting of a single lineage.
Species
A named kind of organism; the basic unit of biological classification. A group of potentially interbreeding natural populations that are capable of producing viable offspring, but not capable of reproducing with other such groups.
Stable Isotope
One of two or more nondecaying (i.e., nonradioactive) atomic versions of a chemical element, each of which has a different atomic mass. In natural Earth systems, stable isotopes can provide clues to past atmospheric temperatures, plant photosynthetic pathways, animal diets and migration, and other phenomena. Some common stable isotopes in natural systems include isotopes of carbon, oxygen, nitrogen, and hydrogen.
Subspecies
A relatively uniform and genetically distinct population of a species, often in a specific geographic region.
Symplesiomorphy
In phylogenetics, an ancestral character shared by two or more groups.
Synapomorphy
In phylogenetics, a derived, homologous character shared by two or more groups.
Systematics
The study of patterns and processes of evolution that are used to construct phylogenies and classify organisms.
Taxon
A named group of organisms of a given category (such as of a species, genus, family, etc.) of classification; e.g., dogs, Artiodactyla, Myotis lucifugus. Plural: taxa.
Taxonomy
The practice of naming and classifying organisms.
