Classification Systems (Part 1) Flashcards

Taxonomists

• Arrange organisms into groups and assign names to them
• Introduced a universal naming system for organisms

Binomial Nomenclature

• Naming system helps avoid errors in identification
• Genus name is capitalized and listed first; species name is lowercase and follows
• Both names are italicized in print

Kingdom

• Broadest category in the Linnaean classification system
• Includes approximately two million species
• Example: gray wolf is classified within the kingdom Animalia, which encompasses all animals

Phylum

• Taxon category for animals with similar body types
• Gray wolf belongs to phylum Chordata, indicating it has a backbone

Class

• Groups organisms by outer covering and parental care methods
• Gray wolf is part of the class Mammalia, which has approximately 5000 species
• Members possess hair for insulation and mammary glands for nursing young

Order

• Taxon category that groups organisms based on dietary habits
• Gray wolf is classified in the order Carnivora, comprising meat-eating mammals

Family

• Taxon category for organisms sharing physical characteristics like teeth type and body shape
• All dog-like animals in Carnivora are classified under the family Canidae, including wolves, jackals, and domestic dogs

Genus

• Taxon category for organisms with closely related characteristics, differentiated by unique traits
• Gray wolf is in the genus Canis, which includes similar dog-like animals while excluding domestic dogs

Species

• The final taxon level, identifying a single organism by unique characteristics
• Gray wolf's species name is lupus, derived from Latin meaning "wolf"

Phylogeny

• Study of evolutionary history of a species, tracing traits to ancestral lineage

Phylogenesis

• Sequence of evolutionary changes within a species, can clarify or modify Linnaean classification

Phylogenetic Tree

• A branching diagram representing evolutionary relationships

Tree Structure

• Phylogenetic tree depicts hypotheses about evolutionary ties
• Relationships shown as dichotomies or two-way branch points indicating species divergence

Branching Relationships

• Organisms C and D are closely related, as well as A and B
• C, D, and E share enough similarities to form a clade based on common ancestry

Clade

• Group of species that share a common ancestor and are categorized together due to this lineage