Classification and Life Diversity Part I

Modern Classification: Taxonomy Branch of biology that groups and names organisms based on studies of their different characteristics Aristotle began simple classification by grouping organisms into two basic groups Plant Animal Linnaeus – Father of modern classification. Used Binomial Nomenclature http://europa.tcs.tufts.edu/teach21c/private/pbu/files/31/aristotl_20020610143002/index.htm During the golden age of Greece, the philosopher, Aristotle began the organized manner of naming living things.  We call the naming of living things Taxonomy.   He divided all living things into plants or animals. He further divided these two classifications into subgroups.  For example, he divided animals into land and water animals.  At this time science, religion, and philosophy had not yet separated into different disciplines.  Because Aristotle, the philosopher, invented the discipline called logic and because of his great influence on the development of western science, his methods weren't questioned for a long time.  However, it eventually became clear to scientists that Aristotle's method was inadequate.  There were too many creatures that didn't seem to fit in either category or had characteristics of both.  So, a better method was needed.Aristotle Born 384 BC, Died 322 BC       A Swedish scientist, Carolus Linnaeus, many years later developed a system that classified living things based upon body structures, size, shape, color, and methods of obtaining food.  The system was called binomial nomenclature.  It is made up of two Latin words.  The first word is the creatures genus and the second is its species name.  Genus is the classification of creatures that have similar characteristics, yet are obviously different.  The species name is the smallest most precise classification where looking at a group of creatures, except for size and some minor color differences, you can tell that they are the same kind of creature. Carolus LinnaeusBorn 1707, Died 1778

Binomial Nomenclature Scientist use LATIN because it is an unchanging language Everything referred to by two names Genus (capitalized) Species (lower case) Both names are underlined or italicized Ex. Canis lupus or Canis lupus (wolf) See page 459

Levels of Classification Taxa Kingdom Phylum Class Order Family Genus Species: can produce fertile offspring

6 KINGDOMS All of life can be divided into 6 kingdoms: Archeabacteria Eubacteria Protista Fungi Plantae Animalia

Technology As new technology develops, scientist can more accurately classify organisms Organisms can be classified by: Similarity of karyotypes (chromosome) Biochemistry (DNA or amino acid sequencing) Embryology Geographic distribution Phylogeny (evolutionary descent) Amino acid sequence exercise pg 439

Taxonomic Tools Cladistics Use evolutionary relationships to create “fan diagrams” or cladograms A cladogram is a branching diagram that shows the relationships of organism Pg 467 MiniLab

Taxonomic Diagrams Phylogenetic Tree Cladogram Taxonomic Diagrams Mammals Turtles Lizards and Snakes Crocodiles Birds Mammals Turtles Lizards and Snakes Crocodiles Birds Phylogenetic Tree Cladogram Taxonomic Diagrams Sometimes, biologists group organisms into categories that represent common ancestries, not just physical similarities. Early naturalists used physical characteristics and later, fossil data, attempting to represent evolutionary relationships among organisms. Today, modern classification systems use fossil data, physical characteristics and DNA/RNA information to draw increasingly more accurate branching diagrams. Phylogenetic trees, or phylogenies, represent hypothesized evolutionary relationships among organisms and may include extinct as well as modern species. Cladograms are based only on characteristics observable in existing species. The branching patterns in a cladogram are defined by the presence of unique, evolving innovations (derived characteristics) shared by all members of the group. References Campbell, Neil E. and Reece, Jane B. 2002. Biology, Sixth Edition. Benjamin Cummings. Judd, W.S., Campbell, C.S., Kellogg, E.S., Stevens, P.F., Monoghue, M.J. 2002. Plant Systematics: A Phylogenetic Approach, Second Edition. Sinauer Assoicates, Inc. Image References: Buffalo (Jack Dykinga), Alligator (USDA), Turkey (Scott Bauer) http://www.ars.usda.gov/is/index.html From USDA Agricultural Research Service Turtle, Snake Art Explosion, Volume 2 Clip Art

Phylogeny The evolutionary history of a species or a group of species over geologic time

See lesson on this: “The Chromosome Connection” at www.BecomingHuman.org Access via ENSI lesson: “Comparison of Hominoid Chromosomes”

Which two organims are most closely related? Taxon House Cat Mountain Lion Dog Human Kingdom Animalia Phylum Chordata Class Mammalia Order Carnivoria Primates Family Felidae Canidae Hominidae Genus Felis Canis Homo Species domesticus concolor familiaris sapiens

Essential Questions 1. What does bionomial nomenclature mean? Classification by 2 names 3. Human’s scientific name is Homo sapien. What is our genus? Homo