Organism Classification and Naming Conventions

Describe

Document the characteristics of organisms, including their morphology, behavior, genetics, and ecological roles.

Identify

Distinguish and recognize organisms based on their unique features, allowing for accurate differentiation from other species.

Name

Assign a formal scientific name following standardized rules (such as binomial nomenclature by Carl Linnaeus).

Classify

Organize organisms into hierarchical groups based on shared characteristics and evolutionary relationships, creating a structured system for biological diversity.

Common Names - Advantages

Easy to remember and use. Familiar to the general public. Often in local languages, making communication easier.

Common Names - Disadvantages

Can vary by region and language, leading to confusion. One species may have multiple common names. Different species may share the same common name.

Scientific Names - Advantages

Universally recognized, avoiding confusion across languages and regions. Unique to each species, preventing ambiguity. Reflects evolutionary relationships and classification.

Scientific Names - Disadvantages

Can be difficult to remember and pronounce. Requires knowledge of Latin or Greek roots. Not widely used by the general public.

Genus

Always capitalized and italicized (or underlined when handwritten).

Specific epithet

Always lowercase and italicized (or underlined when handwritten).

Author citation

The name of the scientist(s) who first described the species, sometimes abbreviated.

Example of scientific naming

Homo sapiens Linnaeus, 1758: Homo (Genus), sapiens (Specific epithet), Linnaeus, 1758 (Author citation).

Rule of priority

The oldest validly published name (with 1753 as the starting point) takes priority.

Synonymy

Other names applied to a taxon (because of invalidly published names, assignment to a new genus, or because taxonomists decided they were multiple descriptions of the same thing) become synonyms.

Type specimen

The designated example of a species tied to that name.

Type species

The designated example species for a genus.

IBCN-recognized ranks

Kingdom, Division (Phylum), -phyta, Class, Order, -ales, Family, -aceae, Genus, Species.

Multiple Authors in a Citation

Multiple authors can appear when a species is described collaboratively or later revised.

Parentheses in Author Citations - Without parentheses

The species name remains in the same genus as originally described.

Parentheses in Author Citations - With parentheses

The species was moved to a different genus after its original description.

Artificial Classification

Based on one or few superficial traits such as size, color, or habitat.

Natural Classification

Based on many characteristics, including morphology, anatomy, genetics, and evolutionary relationships.

Phenetic Classification

Based on overall similarities in observable characteristics without considering evolutionary history. Uses mathematical/statistical methods.

Phylogenetic Classification

Based on evolutionary history and common ancestry. Uses molecular and morphological data.

How to Determine Relatedness

Closer Nodes = Closer Relationship. The fewer nodes (branch points) between two species, the more closely related they are.

Shared Derived Traits (Synapomorphies)

Traits that evolved in a common ancestor and are shared by all its descendants.

Outgroup Comparison

An outgroup is a species that diverged earlier and is used for comparison.