Taxonomy and Phylogeny Flashcards
What is classification?
The process of grouping objects into categories based on shared qualities
Why classify?
Identification of similarities and differences Pattern recognition Allows for evaluation Allows for extrapolation Detection of relationships Effective and efficient communication
What is taxonomy?
the SCIENCE of classification
Linnaeus gave us a two word naming system for species:
binomial nomenclature
Linnaeus gave us a _______ system by grouping smaller categories into larger ones
nested hierarchal classification
Nomenclature definition:
system for naming biodiversity
Taxon:
a group with a specific rank into which related organisms are classified
a general term for any taxonomic group
Nomenclature - every name carries 3 pieces of information, what are they?
- Circumscription
- Rank
- Position
What is circumscription?
to encircle. all the characteristics that define the taxon
What is rank?
the level in the taxonomic hierarchy
What is position?
WITHIN which group does the taxa belong
Nomenclature rules:
Published on paper
Principle of type
Principle of one name (only one name for a particular circumscription, position and rank)
Principle of priority (synonyms, metonym, homonym)
Binomial nomenclature (Linnaeus)
Binomial Nomenclature: Species names ALWAYS:
have two names
Italicized (typed); underlined (hand written)
generic name + specific epithet
Binomial Nomenclature: Generic names:
genus; singular noun; Latin; capitalized
Binomial Nomenclature: Specific Epithet:
lower case; usually descriptive; has to agree in gender to genus
species and genera are both:
plural and singular
when writing, treat a species name as ___
singular
taxonomy provides…
a frame work for understanding biodiversity, an informative language for communication about biodiversity, and the information necessary for the reconstruction of ecological and evolutionary relationships
taxonomy is…
the frame work on which other pieces of biological knowledge are hung allowing for evaluation ad extrapolation
taxonomy reveals…
ecological and evolutionary phenomena on need of further study
How is classification different from identification
Classification is the process of grouping objects onto categories based on shared qualities
Identification is relating an unknown to groups in a previously established classification
What is systematics
the study of the evolutionary processes and relationships responsible for biological diversity
What is phylogeny
a hypothesis of the evolutionary history among various taxa
what is a node
a branching point on a tree
what are the three domains
bacteria, archaea, eukarya
Terminal node:
where taxa of study are ALWAYS located
Internal node:
common ancestor of the lineages descending from this branching point
Lineage:
a continuous line of descent between nodes
Branch:
evolutionary connections between nodes in a phylogeny
Root:
lineage or branch shared by all descendants on a tree
Polytomy:
a section of a phylogeny in which the evolutionary relationships can not be fully resolved to dichotomies
Clade:
a group consisting of a single common ancestor and ALL of its descendants
Basal lineage/basal clade:
the earliest diverging lineage
Sister taxa:
taxa or clades that share a most recent common ancestor
Our group:
a lineage in a phylogenetic analysis that falls outside the clade (group) of interest
Cladistics (phylogenetics):
classifies living organisms on the basis of monophyletic groups
monophyletic clade:
includes an ancestor and all of its descendants
paraphyletic clade:
contains the common ancestor but not all of its descendants
polyphyletic clade:
will have several evolutionary lines that do not necessarily include the most recent common ancestor taxa
Homologous structure:
similar structures derived from a common ancestor
Symplesiomorphy:
shared ancestral characters. a trait that is shared by two or more groups due to inheritance from a DISTANT common ancestor
Synapomorphy:
shared derived characters. a novel evolutionary trait that is shared by two or more groups due to inheritance from an IMMEDIATE common ancestor
homoplasy:
when similar structures are acquired by convergent evolution without a common ancestor
traits evolve more than once
wings
convergent evolution:
filling the same niche but not the same animal
Biological species concept:
a population or group of populations that is reproductively isolated
morphological species concept:
a species is a diagnosable cluster of individuals within which there is a pattern on ancestry and descent, and beyond which there is not
ecological species concept:
a species is a set of organisms exploiting (or adapted to) a single niche
phylogenetic species concept:
the smallest set of organisms that share an ancestor and can be distinguished from other sets
Why should taxonomy be based on synapomorphies and monophyly?
focus on homology emphasize potential out-group diversity illustrate potential ing-roup uniformity focus on novel characteristics make hypothesis comparable by having a common standard
