Classification

It’s alive

Section Objectives: Evaluate the history, purpose, and methods of taxonomy. Explain the meaning of a scientific name (binominal nomenclature). Show the levels of organization (taxa).

Classification The grouping of objects or information based on similarities. Cat Frog

Classification

How Classification Began Taxonomy (tak SAH nuh mee) The branch of biology that groups and names organisms based on studies of their different characteristics. Mother tiger raise piglets after cubs die.

Taxonomists Biologists who study taxonomy.

Aristotle Greek – 384 - 322 B.C. First to develop a biological classification system. Classified things as either a plant or an animal.

Aristotle’s system He subdivided plants into three groups, herbs, shrubs, and trees, depending on the size and structure of a plant. He grouped animals according to various characteristics, including their habitat and physical differences.

Aristotle’s system He subdivided plants into three groups, herbs, shrubs, and trees, depending on the size and structure of a plant.

Aristotle’s system As time passed, more organisms were discovered and some did not fit easily into Aristotle’s groups, but many centuries passed before Aristotle’s system was replaced.

Linnaeus Swedish - (1707 - 1778) Based his classification system on physical and structural similarities. As a result, the groupings revealed the relationships of the organisms.

Example Bats fly but they produce milk for their young. [Are they a bird or a mammal?] Answer: They are Mammals

Linnaeus

How are evolutionary relationships determined? Evolutionary relationships are determined on the basis of similarities in structure, breeding behavior, geographical distribution, chromosomes, and biochemistry.

Structural similarities Structural similarities among species reveal relationships. The presence of many shared physical structures implies that species are closely related and may have evolved from a common ancestor.

Evolutionary Relationships Are determined by similarities in structure, breeding behavior, geographical distribution, chromosomes, and biochemistry (DNA).

Structural similarities For example, plant taxonomists use structural evidence to classify dandelions and sunflowers in the same family, Asteraceae, because they have similar flower and fruit structures.

Similarities Taxonomists observe and compare features among members of different taxa and use this information to infer their evolutionary history.

Classifying Diversity

General Specific Section 18-1 Grizzly bear Black bear Giant panda Red fox Abert squirrel Coral snake Sea star KINGDOM Animalia PHYLUM Chordata CLASS Mammalia ORDER Carnivora FAMILY Ursidae GENUS Ursus SPECIES Ursus arctos Specific

Classification of Organisms Kingdom Phylum / Division Class Order Family Genus Species

Taxonomic rankings Compare the appearance of a lynx, Lynx rufus, a bobcat, Lynx canadensis, and a mountain lion, Panthera concolor. Mountain lion Lynx Bobcat

Domain Eukarya Kingdom Animalia Phylum Chordata Class Mammalia Order Carnivora Family Felidae Genus Lynx Species Lynx canadensis Lynx rufus Bobcat Lynx

What are the taxa they all have in common? Kingdom, Phylum, Class and Order

Binomial nomenclature (Scientific Name) Developed by Linnaeus. The first word used identifies the genus of the organism. The second word, which often describes a characteristic of the organism.

Genus (JEE nus) (plural, genera) consists of a group of similar species. Just because they look alike it doesn’t make them alike.

Latin Is the most common language of scientific names. canis : dog. aranea : spider's web cavus : hole, pit claudus : lame contra : (+ acc.) against decor : beauty, grace

Scientific Names Should be italicized in print and underlined when handwritten. The first letter of the genus name is uppercase, but the first letter of the descriptive name is lowercase. Passer domesticus

Question 1 A. by their common genus B. by their analogous structures How did Aristotle group organisms such as birds, bats, and insects? A. by their common genus B. by their analogous structures C. by their common species D. by their homologous structures

The answer is B. The organisms were grouped together because of their wings, which, in this case, are analogous structures.

Question 2 A. genus B. family C. order D. phylum Which taxon contains the fewest species? A. genus B. family C. order D. phylum The answer: A, genus.

Question 3 What is the difference between “classification” and “taxonomy?” Answer Classification is the grouping of objects or information based on similarities. Taxonomy is the branch of biology that classifies and names organisms based on their different characteristics.

Question 4 What are the two parts that make up binomial nomenclature? Answer Binomial nomenclature comprises a genus name followed by a specific epithet.

Classify the following based on function. Desk Chair Calculator Stool Bookcase Computer lights T.V.

6 Kingdoms

6 Kingdoms Eubacteria Archaebacteria Animals Protists Fungi Plants

Bacteria All bacteria are Unicellular Prokaryotic They were probably the first organisms on the earth.

Bacteria Eubacteria – True bacteria Ex: streptococcus Which causes strep throat.

Bacteria Archaebacteria- Archae means ancient Most are anaerobic, (live in environments with no oxygen).

Animals: Multicellular consumers Heterotrophs. Nearly all are motile. Animal cells do not have cell walls.

Animals Invertebrates & Vertebrates

Protists Plant like Fungus like Animal like The kingdom into which things are placed that can not be placed in any other kingdom.

Kingdom Protista contains Kingdom Protista contains diverse species that share some characteristics Anal pore A Paramecium

Fungi

Fungi: Earth’s decomposers Organisms in Kingdom Fungi are heterotrophs that do not move from place to place. A fungus is either a unicellular or multicellular eukaryote that absorbs nutrients from organic materials in the environment.

Fungi: Earth’s decomposers

Plants: Multicellular oxygen producers Photosynthetic eukaryotes that are stationary. Cape Sundew

What is the branch of biology that groups and names organisms based on studies of their different characteristics? Taxonomy

Who developed binomial nomenclature? Linnaeus

Name the 7 levels of taxa Kingdom Phylum Class Order Family Genus Species

Name the 6 kingdoms. Plant Animal Eubacteria Archaebacteria Protist Fungi

Life’s Six Kingdoms

More Classification Litter hurts Turtle survives!!

Classification

Phylogeny Evolutionary history of a species.

Cladistics Classification system that believes organisms evolved from a common ancestral group. As they evolve they retain some unique traits from that ancestor.

Cladistics

Geographical distribution Probing Bills Grasping Bills Crushing Bills Feeders Cactus Insect Seed Feeders Feeders Fruit Parrot Bills Feeders Ancestral Species

Geographical distribution These finches probably spread into different niches on the volcanic islands and evolved over time into many distinct species. The fact that they share a common ancestry is supported by their geographical distribution in addition to their genetic similarities.

Chromosome comparisons For example, cauliflower, cabbage, kale, and broccoli look different but have chromosomes that are almost identical in structure.

Chromosome comparisons Therefore, biologists propose that these plants are related.

Question 1 A. chromosome comparisons B. biochemistry Which of the following is NOT a way to determine evolutionary relationships? A. chromosome comparisons B. biochemistry C. specific epithets D. geographical distribution The answer is C.

Question 2 How does a cladogram differ from a pedigree? Answer Pedigrees show the direct ancestry of an organism from two parents. Cladograms show a probable evolution from an ancestral group.

Question 3 Allosaurus Velociraptor Robin Archaeopteryx Sinornis Theropods Feathers with shaft, veins, and barbs Flight feathers; arms as long as legs 3-toed foot; wishbone Down feathers Light bones Using the cladogram, which of the following traits would be a primitive trait?

Allosaurus Velociraptor Robin Archaeopteryx Sinornis Theropods Feathers with shaft, veins, and barbs Flight feathers; arms as long as legs 3-toed foot; wishbone Down feathers Light bones The answer is light bones. Primitive traits are traits that evolved very early.

Question 4 Why do taxonomists use Latin names for classification? Answer Latin is no longer used in conversation and, therefore, does not change.

Question 5 What is the relationship between cladistics and taxonomy? Answer Cladistics is one kind of taxonomy that is based on phylogeny.

Question 6 Domain Eukarya Kingdom Animalia Phylum Chordata Class Mammalia Order Carnivora Family Felidae Genus Lynx Species Lynx rufus Lynx canadensis Bobcat Lynx

Both organisms are members of the same kingdom, phylum, class, order, family, and genus but belong to different species.

Question 7 Which taxon contains the others? A. order B. class C. genus D. family The answer is B.

Question 3 Which of the following pairs of terms is NOT related? A. specific epithet – genus B. binomial nomenclature – Linnaeus C. biology – taxonomy D. Aristotle – evolutionary relationships The answer is D.

Question 5 What two main characteristics distinguish the members of the six kingdoms? Answer The two characteristics are differences in cellular structures and methods of obtaining energy.

Question 6 Which of the following is NOT true of both the animal and plant kingdoms? A. both contain organisms made up of cells B. tissues are organized into organs C. cells are organized into tissues D. cells contain cell walls The answer is D.

Question 7 Which of the following describes a fungus? A. autotrophic prokaryote B. unicellular or multicellular heterotroph C. unicellular autotroph D. heterotrophic prokaryote

The answer is B, unicellular or multicellular heterotroph.

Question 10 Why do some scientists believe that plants existed on Earth’s landmasses much earlier than fossils indicate? Answer Plants do not fossilize as often as organisms that contain hard structures, like bones, which more readily fossilize than soft tissues.