Change and Diversity in Life on Earth Unit Learning Goal #5: Explain how species are classified using the science of taxonomy.

Taxonomy The branch of science where scientists classify organisms and assign each a universally accepted name.The branch of science where scientists classify organisms and assign each a universally accepted name.

Why use a dead language? Scientist give a unique scientific name toScientist give a unique scientific name to each species they know about whether it’s alive today or extinct. each species they know about whether it’s alive today or extinct. The scientific name comes from one of two “dead” languages – Latin or ancient Greek. The scientific name comes from one of two “dead” languages – Latin or ancient Greek.

Devil Cat

Ghost Cat

Mountain Lion

Screaming Cat

Puma

Florida Panther

Cougar

There are at least 50 common names for the animal shown on the previous 7 slides.There are at least 50 common names for the animal shown on the previous 7 slides. Common names vary according to region.Common names vary according to region. Soooo……why use a scientific name?Soooo……why use a scientific name?

A two name system for writing scientific names. The genus name is written first. (always Capitalized) The species name is written second. (never capitalized) Both words are italicized if typed or underlined if hand written. Example: Felis concolor or F. concolor Which is the genus? The species? Binomial Nomenclature

The evolutionary history of an organism, is the cornerstone of a branch of biology called systematic taxonomy. Systematics, as systematic taxonomy is commonly called, is the study of the evolution of biological diversity. Phylogeny

A phylogenetic tree is a family tree that shows a hypothesis about the evolutionary relationships thought to exist among groups of organisms. It does not show the actual evolutionary history of organisms.

Phylogenetic trees are usually based on a combination of these lines of evidence: Fossil record Morphology Embryological patterns of development Chromosomes and DNA

Cladogram Diagrams that shows the evolutionary relationships between living organism.

A key is a device for easily and quickly identifying an unknown organism. The dichotomous key is the most widely used type in biological sciences. The user is presented with a sequence of choices between two statements, couplets, based on characteristics of the organism. By always making the correct choice, the name of the organism will be revealed. The Dichotomous Key

Domain Archaea – Includes newly discovered cell types – Contains 1 kingdom – the Archaebacteria Domain Bacteria – Includes other members of old kingdom Monera – Has 1 kingdom – the Eubacteria Domain Eukarya - Includes all kingdoms composed of organisms made up of eukaryotic cells – Protista – Fungi – Animalia – Plantae The Three Domains

The major classification levels, from most general to most specific (several of these have subdivisions) A group at any level is a taxon.

Kingdoms are divided into groups called phyla Phyla are subdivided into classes Classes are subdivided into orders Orders are subdivided into families Families are divided into genera Genera contain closely related species Species is unique Categories within Kingdoms

Six Kingdoms EUBACTERIA Prokaryotes (no nucleus); always unicellular (single- celled). Bacteria. May have plant, fungus, or animal characteristics. ARCHAEA Prokaryotes; always unicellular. Adapted to unusual and/or extreme conditions, such as very hot, very salty, or no-oxygen environments. Have several different cellular chemistries from eubacteria. PROTISTA Eukaryotes (nucleus in cell); mostly unicellular, or collections of very similar cells. May have plant, fungus, or animal characteristics.

. PLANTAE Eukaryotes; multicellular; capable of photosynthesis, production of complex molecules from simple molecules using light. ANIMALIA Eukaryotes; multicellular; must obtain complex food molecules from external source, broken down and absorbed internally. Usually capable of movement. FUNGIEukaryotes; almost all multicellular; must obtain complex food molecules from external source, absorbed through external surface. Almost never capable of movement