Classification/Taxonomy

Why Classify? Why Classify? To study the diversity of life, biologists use a classification system to name organisms, group them in a logical manner, and study evolutionary relationships. evolutionary relationships.

Taxonomy Defined: Discipline of classifying organisms and assigning each organism a universally accepted name. In other words, naming things.

Why common names don’t work Common names vary among different languages. Cat Cat Arabic: quttah Arabic: quttah Czech: kocka Czech: kocka French: chat French: chat German: katze German: katze Japanese: neko Japanese: neko Russian: kotchka Russian: kotchka Spanish: gato Spanish: gato

Why common names don’t work Common names vary among different countries. Example: United Kingdom – Buzzard refers to a hawk United States – Buzzard refers to a vulture Red-tailed HawkHoney BuzzardTurkey Vulture

Why common names don’t work Many species have several common names. Sand tiger shark Sand tiger shark Sand shark Sand shark Gray nurse shark Gray nurse shark

Why common names don’t work Dolphin Mahi mahi Turciops truncatus Same common name used for different species

First Attempt to Classify Aristole (Greek Philosopher) * About 300 BC * About 300 BC * Classified based on method of reproduction * Classified based on method of reproduction * Used the words like “genera” and “species” * Used the words like “genera” and “species” * Grouped animals between those with blood and * Grouped animals between those with blood and those without blood those without blood * He had many errors in his classification system, but it * He had many errors in his classification system, but it was used until the 1700s was used until the 1700s

Carolus Linnaeus (1707 – 1778) (1707 – 1778) Created the system of naming we use today. Created the system of naming we use today. In taxonomy, a group or level of organization is called a taxonomic category or taxon. In taxonomy, a group or level of organization is called a taxonomic category or taxon.

Binomial Nomenclature “Bi” means 2 “Bi” means 2 “nomial” means naming “nomial” means naming Nomenclature means “the system of” Nomenclature means “the system of” Defined: In Binomial Nomenclature, each species is assigned a two-part scientific name. (genus & species)

Example of Binomial Nomenclature Polar Bear is Ursus maritimus Polar Bear is Ursus maritimus Ursus: genus Ursus: genus Ursus contains 5 other kinds of bears Ursus contains 5 other kinds of bears maritimus: species maritimus: species The Latin word, maritimus, refers to the sea. The Latin word, maritimus, refers to the sea. Polar bears often live on pack ice that floats in the sea. Polar bears often live on pack ice that floats in the sea.

Here We Go… Polar Bear Species: maritimus Genus: Ursus Family: Ursidae Order: Carnivora Class: Mammalia Phylum: Chordata Kingdom: Animilia What do these mean?...lets see *Do NOT have to write*

What they mean Species: maritimus (lives in marine environment) Genus: Ursus (kind of bear) Family: Ursidae (larger category of bears) Order: Carnivora (meat-eating animals) Class: Mammalia (warm-blooded, hair, & milk) Phylum: Chordata (vertebrates) Kingdom: Animilia (there are 6 kingdoms) *Do NOT have to write*

How to remember: a King Phillip Came Over For Green Salad Da King Phillip Came Over For Green Salad Domain Domain Kingdom Kingdom Phylum Phylum Class Class Order Order Family Family Genus Genus Species Species

Phylum Chordata Class Mammalia Order Carnivora Family Ursidae Genus Ursus Species maritimus

Rules of the Game Uniqueness: Every name has to be unique. Universality: Zoologists have adopted, by International Code of Zoological Nomenclature, a set of rules for naming animals. A single language is to be used on a worldwide basis. All animals are given a generic name (common name) and specific name in Latin &/or Greek (scientific name). These names are in italics when TYPED or are underlined when HAND WRITTEN. or are underlined when HAND WRITTEN. Human: Homo sapiens Lion: Panthera leo

Taxonomy Video

If these three species belong to the same genus, they are descended from a common ancestor. Genus species Felis domestica negripes margarita Sand cat` Black Footed Cat Domestic Cat Felis domestica Felis negripes Felis margarita

A Problem with Traditional Classification Traditional classification systems relied on body structure comparisons Traditional classification systems relied on body structure comparisons only (not DNA) only (not DNA) Due to convergent evolution, organisms that are quite different from each Due to convergent evolution, organisms that are quite different from each other evolve similar body structures. other evolve similar body structures. Convergent Evolution : Process by which unrelated organisms independently evolve similarities when adapting to similar environments. Flying Squirrel… Live in the US (GA) Sugar Glider… Live in Australia Look similar, but totally unrelated!

Another Problem with Traditional Classification Example: The Crab, The barnacle, & The limpet The barnacle and the limpet have similarly shaped shells & look alike The barnacle and the limpet have similarly shaped shells & look alike The crab has a very different body form The crab has a very different body form Based on anatomy, the barnacle & limpet could be classified together and the crab in a different group. Based on anatomy, the barnacle & limpet could be classified together and the crab in a different group.

Related This incorrect because crabs and barnacles are actually related

Modern Principles of Classification Modern classification system has its roots in the Modern classification system has its roots in the system of Linnaeus system of Linnaeus Modern classification has been revised to reflect Modern classification has been revised to reflect Darwinian Principle of common descent Darwinian Principle of common descent Most recently, molecular systematics (DNA) has driven the most recent revisions in classification Most recently, molecular systematics (DNA) has driven the most recent revisions in classification

Crustaceans Even though they do not look a like, crabs & barnacles are actually related Gastropods Molted Exoskeleton Segmentation Free swimming Larva

Evolutionary Classification Biologists now group organisms into categories that represent lines of evolutionary descent, not just physical similarities Biologists now group organisms into categories that represent lines of evolutionary descent, not just physical similarities Evolution Classification : Is the strategy of grouping organisms together based on their evolutionary history.

Classification Using Cladograms Cladogram : A diagram that shows the evolutionary relationships among a group of organisms.

Crustaceans Using Cladograms, you can see that crabs and barnacles share similar characteristics because they both molt & are segmented Gastropods Molted Exoskeleton Segmentation Free swimming Larva

Crustaceans You can also see that ALL have a free swimming larva stage Gastropods Molted Exoskeleton Segmentation Free swimming Larva

The Three-Domain System In 1990, a new taxonomic level called Domain was introduced and changed how bacteria were classified. In 1990, a new taxonomic level called Domain was introduced and changed how bacteria were classified. Domain Archaea Domain Archaea Domain Bacteria Domain Bacteria Domain Eukarya Domain Eukarya There are 6 Kingdoms total: There are 6 Kingdoms total: 1. Eubacteria 2. Archaebacteria 3. Protista 4. Fungi 5. Plantae 6. Animalia Both are Bacteria Everything else (Except viruses)

6 Kingdoms Eubacteria Archaebacteria Protista Fungi Plantae Animalia E. ecoliParamecium Fern frod H. coccineaHomo sapiensPyrococcus furiosus Prokaryote Eukaryote Autotroph or heterotroph Autotroph or heterotroph Autotroph/ heterotroph Heterotroph Autotroph Most common bacteria Live in very hot places Includes Algae Don’t belong in other euk Cell walls & Chloroplasts Release enzymes to digest food No cell wall No chloroplasts Multicellular “Ancient Bacteria”

Phyla To Know Porifera: Sponges Cnidaria: Jellyfish, Sea Anemones, Corals Echinodermata: Sea Urchin, Starfish, Sand Dollars Mollusca: Snails, Clams, Octopus Arthropoda: Insects, Crustaceans, Spiders Chordata: Vertebrates

The End.