Chapter 18 Classification Organization and naming systems based on morphology and genetics Humans have a tendency to see commonalities and differences, clustering images by appearance.

Aristotelian classification Life Plant Animal Herb Shrub Tree Aristotle grouped organisms based on appearance and abilities.

Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical manner. To avoid the confusion caused by regional common names. Texas bluebonnet (Lupinus texensis )

Taxonomy the science of classification Uses Latin…descriptive, universal, “dead” language that never changes Uses binomial nomenclature Two word naming system of Genus & species = scientific name Uses hierarchy of categories from general to specific

Common names Many people refer to organisms by common names rather than scientific names. Be careful that common names do not always reflect the biology of the organism. Example: starfish are not “fish”

Comparing related animals Lynx Bobcat Lynx rufus, lynx Panthera concolor, mountain lion Lynx canadensis, bobcat Which two are more related? How do you know? Mountain lion

Dichotomous key: system to identify organisms and their scientific names A key is made up of sets of numbered statements. Each set deals with a single characteristic of an organism, such as leaf shape or arrangement.

Carolus Linnaeus (1707-1778) Created a classification system with seven hierarchical levels Kingdom Phylum Class Order Family Genus species

Human classification: Kingdom Animalia Phylum Chordata Class Mammalia Order Primates Family Hominidae Genus Homo species sapiens

KINGDOM Animalia PHYLUM Chordata CLASS Mammalia ORDER Carnivora Giant panda Grizzly bear Black bear Abert squirrel Coral snake Red fox KINGDOM Animalia Sea star PHYLUM Chordata CLASS Mammalia ORDER Carnivora FAMILY Ursidae GENUS Ursus SPECIES Ursus arctos

Classification of Human and Chimp Level Human Chimp Kingdom Animalia Phylum Chordata Class Mamalia Order Primate Family Hominidae Pongidae Genus Homo Pan species sapien troglodytes

Kingdom…Phylum…Class…Order…Family… Genus species…(variety) or (breed)

Phylogeny Studying the evolutionary history and relationships of organisms

Cladograms Making a Family Tree Represent evolutionary relationships, phylogeny, and not just physical appearances

Cladograms Cladistics: a phylogenic study that assumes how groups of organisms diverged and evolved Allosaurus Velociraptor Archaeopteryx Sinornis Theropods Flight feathers; arms as long as legs 3-toed foot; wishbone Down feathers Feathers with shaft, veins, and barbs Light bones

Traditional classification vs. Cladograms Appendages Conical Shells Crustaceans Gastropod Crab Barnacle Limpet Crab Barnacle Limpet Molted exoskeleton Segmentation Tiny free-swimming larva CLASSIFICATION BASED ON VISIBLE SIMILARITIES CLADOGRAM BASED ON DERIVED CHARACTERS

Current six-kingdom classification Archaebacteria: prokaryotic Eubacteria: prokaryotic Protists: eukaryotic Fungi: eukaryotic Plants: eukaryotic Animals: eukaryotic

Modern classification systems include the three-domain system which includes the 6 kingdom system. Just a few years ago, all bacteria and some protists were labeled Monera.

Three Domain System DOMAIN EUKARYA DOMAIN ARCHAEA DOMAIN BACTERIA Kingdoms Eubacteria Archaebacteria Protista Plantae Fungi Animalia

Key Characteristics of Domains and Kingdoms Classification of Living Things DOMAIN KINGDOM CELL TYPE CELL STRUCTURES NUMBER OF CELLS MODE OF NUTRITION EXAMPLES Bacteria Eubacteria Prokaryote Cell walls with peptidoglycan Unicellular Autotroph or heterotroph Streptococcus, Escherichia coli Archaea Archaebacteria Prokaryote Cell walls without peptidoglycan Unicellular Autotroph or heterotroph Methanogens, halophiles Protista Eukaryote Cell walls of cellulose in some; some have chloroplasts Most unicellular; some colonial; some multicellular Autotroph or heterotroph Amoeba, Paramecium, slime molds, giant kelp Fungi Eukaryote Cell walls of chitin Most multicellular; some unicellular Heterotroph Mushrooms, yeasts Eukarya Plantae Eukaryote Cell walls of cellulose; chloroplasts Multicellular Autotroph Mosses, ferns, flowering plants Animalia Eukaryote No cell walls or chloroplasts Multicellular Heterotroph Sponges, worms, insects, fishes, mammals

Prokaryotic or eukaryotic Unicellular or multicellular Six Kingdom classification Prokaryotic or eukaryotic Unicellular or multicellular Autotroph or heterotroph Archaebacteria Eubacteria Protista Fungi Plantae Animalia Pro Uni both Pro Uni both Eu most uni both Eu most multi hetero Eu multi auto Eu multi hetero

Archaebacteria overview prokaryotic Most live in extreme environments such as swamps, deep-ocean hydrothermal vents, and seawater evaporating ponds. Most do not use oxygen to respire. Examples: Thermophiles, Halophiles, Methanogens

Eubacteria overview prokaryotic very strong cell walls a less complex genetic makeup than found in archaebacteria or eukaryotes diverse habitat Examples: Strep, Lacto-bacillus, E. coli

Protist overview diverse species that share some characteristics. eukaryote lacks complex organ systems lives in moist environments diverse metabolism

Protozoans: animal-like protists Heterotroph: consume organic matter Unicellular Examples: Amoeba, paramecia

Algae: plant-like protists Autotroph: uses light to make sugars through photosynthesis Lack roots, stems, and leaves Examples: algae, kelp, sea-weed

Fungus-like protists Decompose dead matter Motility during some stage of life cycle No chitin in cell walls Examples: Slime-mold, powdery mildew

Fungi overview Eukaryotic Decomposes matter by absorbing materials Multicellular or unicellular Examples: bread mold, mushrooms, athletes foot, ring worm

Plant overview Eukaryotic Multicellular Photosynthetic: produce oxygen Immobile, sessile Cell walls Examples: fruit, ferns, mosses, trees, grasses

Animal overview Eukaryotic Multicellular Mostly mobile Lack cell walls Diverse habitats Examples: lions, tigers & bears, oh my!

Evolution and the 6 Kingdoms Nutritional types Auto(photo) Hetero(absorb) Hetero(ingest) Plantae Fungi Animalia (Seaweeds) Multi Uni Protista Eu Pro Bacteria Evolution and the 6 Kingdoms

Prokaryotic or eukaryotic Unicellular or multicellular Six Kingdom classification Prokaryotic or eukaryotic Unicellular or multicellular Autotroph or heterotroph Archaebacteria Eubacteria Protista Fungi Plantae Animalia Pro Uni both Pro Uni both Eu most uni both Eu most multi hetero Eu multi auto Eu multi hetero

Classification systems video Click on image to play video.

Click on image to play video. Panthera leo? (1) Click on image to play video.

Click on image to play video. Panthera leo? (2) Click on image to play video.