Chapter 17: Organizing Life’s Diversity Taxonomy Chapter 17: Organizing Life’s Diversity

What is Taxonomy? Discipline of classifying organisms and assigning each organism a universally accepted name.

Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical manner. When taxonomists classify organisms, they organize them into groups that have biological significance.

Common Names vs. Scientific Names Common Names can be confusing one organism can have many different names The Cougar is also known as a: Puma, Mountain Lion or Catamount Each organism only has ONE scientific name (species name) No matter where you are in the world the Cougar is Felis concolor

Assigning Scientific Names Aristotle was a Greek philosopher who was the first to classify or group living things. He classified organisms into two groups: Plants and Animals He subdivided those groups as well. Plants were subdivided into: Herbs, Shrubs and Trees Animals were subdivided based on their habitat and physical characteristics

Assigning Scientific Names A Swedish botanist named Carolus Linnaeus developed Binomial Nomenclature, a two-word naming system for naming all species on earth. It is based on physical and structural similarities Still used today

Why does everything have a weird name in Biology? Everything in science is named using Latin. Why? Latin is a dead language and won’t change meanings with slang or invention. “That is SO gay!!!” Example: Merriam Webster Dictionary definition: Gay – (gA) adjective; 1 a : happily excited : MERRY <in a gay mood> b : keenly alive and exuberant : having or inducing high spirits <a bird's gay spring song>2 a : BRIGHT, LIVELY <gay sunny meadows> b : brilliant in color

4 Reasons for using Latin dead language and will not change not misleading like a common name more descriptive basis for many other languages; English, French, Spanish, Italian and Portuguese

Binomial Nomenclature Each organism has a name consisting of two words Examples: Homo sapiens Tyto alba Common Name: Human Common Name: Barn Owl

Binomial Nomenclature Homo sapiens Tyto alba The first part of the scientific name is the genus. This word is always written first and the first letter is capitalized. It appears in italics or is underlined.

Binomial Nomenclature Homo sapiens Tyto alba The second part of the scientific name is the specific epithet or species name. This word is always written second and the first letter is lower-case. It appears in italics or is underlined.

The 8 Levels of Classification They are, from largest to smallest Domain (this is a relatively new level separates Archaea, Bacteria and Eukaryota) Kingdom (separates plants from animals) Phylum (separates into major groups within the Kingdom; plural: phyla) Class (breaks Phyla down into smaller groups) Order (even more specific) Family (very similar characteristics) Genus (reproductive grouping) Species (most specific)

Come Did King Phillip Over For Good Soup Species Genus Family Order Class For Phylum Good Kingdom Soup Domain

8 levels of Classification You vs. Barn Owl Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Primates Family: Hominidae Genus: Homo Species: H. sapiens Kingdom: Animalia Phylum: Chordata Class: Aves Order: Strigiformes Family: Tytonidae Genus: Tyto Species: T. alba

THINKING CRITICALLY Organism Kingdom Phylum Class Order Family Genus Cat Wolf Fly Kingdom Animalia Phylum Chordata Arthropoda Class Mammalia Insecta Order Carnivora Diptera Family Felidae Canidae Muscidae Genus Felis Canis Musca Species F. domesticus C. lupus M. domestica Have students study this chart. The next slide lists three questions to answer using this chart. You may have to advance to the next slide, let students read the question and then come back to the chart so they can find the answer.

THINKING CRITICALLY What are the kingdom and class of Musca domestica? From the table, which 2 animals are most closely related? 3. At what classification level does the evolutionary relationship between cats and wolves diverge (become different)? Animal; insect Cat and Wolf Family Level

EVOLUTIONARY CLASSIFICATION Biologists group organisms into categories that represent lines of evolutionary descent, or phylogeny, not just physical similarities. Define Phylogeny: The study of evolutionary relationships among organisms.

Classification using Cladograms Cladograms are diagrams that use derived characteristics to illustrate evolutionary relationships. Definition of Clade: A group of organisms, such as a species, whose members share homologous features derived from a common ancestor.

EVOLUTIONARY CLASSIFICATION B C D E F Clade or lineage TIME The American Heritage® Dictionary of the English Language, Third Edition copyright © 1992 by Houghton Mifflin Company. Electronic version licensed from INSO Corporation; further reproduction and distribution restricted in accordance with the Copyright Law of the United States. All rights reserved. Speciation: formation of two new species from one

Classification using Cladograms The cladogram on the next slide shows the evolutionary relationship among several vertebrates.

CLADOGRAM Jaws Lungs Claws or Nails Feathers Hagfish Fish Frog Lizard Pigeon Mouse Chimp Fur & Mammary Glands

Cladogram “Mini-Lab”

Using a Cladogram to Show Relationships Procedure The following table shows the presence or absence of six derived traits in the seven dinosaurs that are labeled A - G. Use the information listed in the table below to answer the following questions.

Using a Cladogram to Show Relationships Derived Traits of Dinosaurs Dinosaur Trait Dino A Dino B C D Dino E F Dino G Hole in hip socket Yes Extension of pubis bone No Unequal enamel on teeth Skull has “shelf” in back Grasping hand Three-toed hind foot

ANALYSIS 1. Classify Complete the missing information on the right side of the partially completed cladogram. A B C D E F G Three-Toed Hind Foot 6 2 5 Grasping Hand 2 4 1