Diversity, Taxonomy & Systematics (Video)

Vocabulary flashcards to review key terms from the lecture notes on diversity, taxonomy, and systematics.

Systematics

The scientific study of biological diversity, its evolutionary history, and resulting classification.

Phylogeny

The evolutionary history and relationships among organisms, depicted as a tree of life.

Tree of Life

A diagram showing genealogical relationships of organisms with ancestral species at the base.

Binomial nomenclature

Two-part naming system for species using the genus and species epithet; introduced by Linnaeus; genus is capitalized and often abbreviated.

Genus

A taxonomic rank; a group of related species; a noun that is capitalized and can stand alone in a binomial name.

Specific epithet

The second part of a binomial name; lower case and cannot stand alone.

Species Plantarum

Linnaeus’s 1753 work that standardized binomial nomenclature and introduced abbreviated genus names.

Linnaeus

18th-century scientist who developed the modern binomial system and emphasized reproductive structures for naming.

Theophrastus

4th-century BC early plant classifier who divided plants into trees, shrubs, and herbs.

Monophyletic

A group derived from a single ancestor and including all of its descendants.

Paraphyletic

A group that does not include all descendants of a common ancestor.

Polyphyletic

A group whose members descend from more than one common ancestor; not a natural grouping.

Cladistics

A method of classification based on monophyletic groups and shared derived traits.

Molecular data

DNA-based information used to infer evolutionary relationships and construct phylogenies.

Chloroplast genome

DNA from chloroplasts, commonly used in plant phylogenetics.

Mitochondrial DNA

DNA in mitochondria; in plants it evolves slowly and can be less informative for phylogenetics.

ICBN (International Code of Botanical Nomenclature)

Governing rules for botanical names; main rule is priority of date published.

Priority of date published

The principle that the earliest validly published name takes precedence.

Domain

Highest taxonomic rank above kingdom; includes Bacteria, Archaea, and Eukarya.

Kingdoms

Traditional major taxonomic groups; in the five-kingdom system: Monera, Protista, Fungi, Plantae, Animalia.

Division/Phylum

Rank used in plants (division) and in animals (phylum); often ends with -phyta in plants.

Magnoliophyta

Division/Phylum of flowering plants (angiosperms).

Magnoliopsida

Class that groups dicots within flowering plants.

Monocotyledons

Seed plants with a single seed leaf (cotyledon).

Eudicotyledons

A clade of flowering plants that includes most dicots and their descendants.

Dicots

Historically a broad group of flowering plants now considered polyphyletic and not a natural group.

Polynomials

Long descriptive plant names used before binomial nomenclature, later replaced by two-part names.

Binomial system

Linnaean two-part naming system using genus and species epithet.

Species concept

Various definitions of what a species is, including Biological, Morphological, Ecological, and Phylogenetic concepts.

Biological species concept

A group that can interbreed and produce fertile offspring; fossils and asexual organisms pose problems.

Morphological species concept

Species defined by morphological differences; can be subjective.

Ecological species concept

Species defined by ecological niches and adaptations.

Phylogenetic species concept

A set of organisms with a unique genetic history, traced by DNA.

Allopatric

Speciation due to geographic range separation and reproductive isolation.

Sympatric

Speciation without geographic separation.

Autopolyploidy

Doubling of chromosomes within a single species leading to reproductive isolation.

Allopolyploidy

Polyploidy resulting from hybridization between species followed by chromosome doubling.

Diploid

Cell or organism with two sets of chromosomes.

Haploid

Cell or organism with a single set of chromosomes.

Meiosis

Cell division producing haploid gametes; reduces chromosome number.