Organizing Life’s Diversity Honors Biology Ch. 17 Organizing Life’s Diversity

I. The History of Classification Taxonomy: - the science of identifying, naming, and classifying organisms

A. Early Classification Systems 1. Aristotle: a. Devised First Classification System - Animals (red-blooded and bloodless) - Plants (trees, shrubs, and herbs) - 2 problems: 1) superficial categories 2) used common names

B. Disadvantages of Common Names: 1. Confusing - ex. mountain lion, cougar, puma, panther, catamount Puma concolor

2. Misleading -. ex. starfish, jellyfish, cuttlefish, 2. Misleading - ex. starfish, jellyfish, cuttlefish, crawfish, silverfish

Microplitis demolitor 3. Language Problems - local names - names used by different languages - some organisms have no common name Microplitis demolitor

2. Carolus Linnaeus - developed modern classification system - Swedish botanist (1700’s) - 2 important innovations:

a. Binomial Nomenclature - two-word naming system: genus & species - gives a unique, universal name for every species Carolus Linnaeus

Honey Bee Apis mellifera Apis pubescens, thorace subgriseo, abdomine fusco, pedibus posticis glabris, utrinque margine ciliatus

1) Genus: 2) Species: - 1st word, small group - usually a Latin noun, capitalized 2) Species: - 2nd word, particular type - Latin adjective, lower case

3) Examples: - Homo sapiens humans - Tyrannosaurus rex

3) Examples: - Acer macrophyllum bigleaf maple - Acer rubrum red maple - Acer saccharum sugar maple Acer pennsylvaticum Acer rubrum Acer circinatum Acer saccharum

3) Examples: - Sequoia gigantum giant sequoia - Tsuga heterophyllum western hemlock - Pseudotsuga menziesii Douglas-fir

b. Hierarchy of Classification Groupings Domain Kingdom Phylum Class Order Family Genus Species Eukarya Animalia Chordata Mammalia Carnivora Canidae Canis lupus

b. Hierarchy of Classification Groupings Did King Phillip come often for ginger snaps? Eukarya Animalia Chordata Mammalia Carnivora Canidae Canis lupus Domain Kingdom Phylum Class Order Family Genus Species

Hierarchy of Taxa

II. Taxonomy Today - Classification systems change constantly. - Taxonomists do not always agree on how to classify organisms.

A. Determining Species 1. Typological Species Concept - a group of organisms that are physically similar to each other

2. Biological Species Concept - a group of organisms that is able to interbreed and produce fertile offspring in a natural setting - cannot be used with extinct or asexual organisms Similarity between different species Diversity within a species

3. Phylogenetic Species Concept - defines a species as a set of organisms with a unique genetic history

B. Characters - inherited features (morphological or biochemical) that vary among organisms

1. Morphological Characters - similarities indicate common ancestry - include homologous structures: different functions but have similar underlying anatomy

- does not include analogous structures: similar functions but different underlying anatomy Eastern Mole Marsupial ‘Mole’

2. Biochemical Characters - The greater the similarities in certain compounds (DNA, proteins, etc.), the more closely related organisms are. Species Human Rhesus monkey Mouse Chicken Frog Lamprey 14% 54% 69% 87% 95% 100% Percent of Amino Acids That Are Identical to the Amino Acids in a Human Hemoglobin Polypeptide Comparison of a Protein Found in Diverse Vertebrates

A Molecular Homology

3. Molecular “Clock” - Mutations occur randomly and accumulate over time. - Mutations that don’t affect survival can be used to estimate time. The Constant Rate of Evolution of the α-globin

C. Phylogenetic Reconstruction Phylogeny of Whales C. Phylogenetic Reconstruction - Phylogeny is the evolutionary history of a species.

1. Character Types - Ancestral characters are shared by ancestral organism and all of its descendents. - Derived characters are shared by one group of organisms but not the ancestor. Leopard Hair Amniotic egg Four walking legs Hinged jaws Vertebral column Turtle Salamander Tuna Lamprey Lancelet (outgroup) Phylogenetic Tree of Chordates

2. Cladograms (Phylogenetic Tree) - a branching diagram that represent the proposed phylogeny of a group of organisms Phylogenetic Tree of Dinosaurs

Phylogeny of Bears Ursininae Tremarclinae Ailuropodinae Ailuridae Musteloidae Procyonidae Caniformia Ursidae Phylogeny of Bears

III. Domains and Kingdoms - Most scientists today use the 3 domain system to classify organisms: Bacteria, Archaea, and Eukarya.

The Three Domains of Life Fungi EUKARYA Trypanosomes Green algae Land plants Red algae Forams Ciliates Dinoflagellates Diatoms Animals Amoebas Cellular slime molds Leishmania Euglena Green nonsulfur bacteria Thermophiles Halophiles Methanobacterium Sulfolobus ARCHAEA COMMON ANCESTOR OF ALL LIFE BACTERIA (Plastids, including chloroplasts) Green sulfur bacteria (Mitochondrion) Cyanobacteria Chlamydia Spirochetes The Three Domains of Life

A. Domain Bacteria - includes the kingdom Eubacteria - prokaryotes whose cell walls contain peptidoglycan

B. Domain Archaea - Prokaryotes that represent an ancient form of life - more closely related to our eukaryotic ancestors - called extremophiles because they can live in extreme environments

C. Domain Eukarya - includes all eukaryotes - contains: Kingdom Protista Kingdom Plantae Kingdom Fungi Kingdom Animalia

1. Kingdom Protista - eukaryotic organisms - unicellular, colonial, or multicellular

2. Kingdom Plantae - photosynthetic multicellular eukaryotes - have cell walls made of cellulose - nonmotile

3. Kingdom Fungi - unicellular or multicellular eukaryote - heterotrophic (absorb nutrients) - have cell walls made of chitin - nonmotile

3. Kingdom Fungi - unicellular or multicellular eukaryote - heterotrophic (absorb nutrients) - have cell walls made of chitin - nonmotile

4. Kingdom Animalia - heterotrophic, multicellular eukaryotes - complex organ systems - motile - obtain food by ingestion

The End

- Order Carnivora

Linking Classification and Phylogeny Species Canis lupus Panthera pardus Taxidea taxus Lutra lutra latrans Order Family Genus Carnivora Felidae Mustelidae Canidae Lutra Panthera

A Phylogenetic Tree of Birds and Their Close Relatives Common ancestor of crocodilians, dinosaurs, and birds Birds Lizards and snakes Crocodilians Ornithischian dinosaurs Saurischian

Hippidion and other genera Phylogeny of Horses Recent (11,500 ya) Pleistocene (1.8 mya) Pliocene (5.3 mya) Miocene (23 mya) Oligocene (33.9 mya) Eocene (55.8 mya) Equus Hippidion and other genera Nannippus Pliohippus Neohipparion Hipparion Sinohippus Megahippus Callippus Archaeohippus Merychippus Parahippus Hypohippus Anchitherium Miohippus Mesohippus Epihippus Orohippus Paleotherium Propalaeotherium Pachynolophus Grazers Browsers Key Hyracotherium