Chapter 18: Classification

Section 18-1: Finding Order in Diversity

Linnaeus's System of Classification Uses taxonomic categories (ranks) that are based on shared morphological (physical), behavioral, and biochemical characteristics: Domain Kingdom Phylum Class Order Family Genus Species smallest, least inclusive rank Largest, most inclusive rank

Linnaeus's System of Classification A taxon (plural: taxa) is a group of organisms at a certain rank. (The animal taxon is at the rank kingdom.) Species together in a smaller taxon automatically also share all their larger taxa. –If they’re in the same phylum, they’re also in the same kingdom and domain. –Same order? Also same phylum, kingdom, and domain. –Same family? Also same order, class, phylum, kingdom, and domain. –Same species? Same everything else! Domain

Linnaeus's System of Classification Here is the classification for a leopard. –Cats are also in the family Felidae. What phylum are cats in? –Dogs are in the order Carnivora. What class are dogs in? –Chimps are in the class Mammalia. Does that mean chimps are in the genus Panthera?

Linnaeus's System of Classification Classification mirrors relatedness. The more taxa two species share, the more closely related they are and the more recent their LCA.

Assigning Scientific Names Binomial nomenclature – 2 part naming system Typed in italics or underlined when hand written 1st word is capitalized and is the organism’s genus 2nd word is lower case and is the organism’s species Example: polar bear – Ursus maritimus

Dichotomous Keys Dichotomous Key – tool used to help identify unfamiliar organisms

Section 18-2: Modern Evolutionary Classification

Cladograms Cladogram or Phylogenetic Tree – diagram that shows evolutionary relationships among a group of organisms / Shows order of divergence Derived characteristics – are characteristics that appear in recent parts of a lineage but not in its older members

Who are chimpanzees most closely related to? Apes Who has a more recent common ancestor with humans, apes or orang-utangs? Who has the most common ancestor with velvet monkeys? Who are more closely related to the gibbons, the chimpanzees or leaf monkeys? Baboons and Macaques Chimpanzees

Circle the location of the most recent common ancestor of pigeons and lizards. Here! To find a common ancestor, trace their lineages BACK towards the origin until the nearest place that the two lineages meet.

Which species is more closely related to salamanders, lizards or perch? Lizards! The more recent the last common ancestor (LCA), the more related. LCA with Lizards LCA with Perch

Which species is more closely related to mice, chimps or pigeons? Chimps!

(Tricky) Which species are perch most closely related to? All but hagfish: Salamanders, Lizards, Pigeons, Mice, and Chimps! The LCA is equally recent for all of them.

Which species is more closely related to salamanders, perch or hagfish? Perch!

How to construct a cladogram 1.Construct a table of characteristics that have have been derived by the evolutionary process (a.k.a. have evolved).

2.Compare the organisms to see if they share derived characteristics. For example, all but the amoeba share the common derived trait of being multicellular, but only the cat and the kangaroo share the derived trait of hair.

3.Using the patterns of shared derived characteristics, construct a cladogram as a series of Y’s or branches. At every Y, the organism that does not share a common characteristic with the rest of the group should be "branched off". Also, indicate the derived characteristics on the branches using dots.

Section 18-3: Domains and Kingdoms

The Domains Organisms are classified into one of 3 different domains (archaea, bacteria, and eukarya). Bacteria Eukarya Archaea

Domain: Bacteria (Old Kingdom: Eubacteria) Cell Type: Prokaryotic # of Cells: Unicellular Cell Characteristics: cell walls with peptidoglycan (thick, rigid carbohydrates) Nutrition: Auto or Heterotroph What makes them unique: can live anywhere from free-living in soil or deadly parasites Examples: E.coli, Streptococcus

Domain: Archea (Old Kingdom: Archeabacteria) Cell Type: Prokaryotic # of Cells: Unicellular Cell Characteristics: cell walls WITHOUT peptidoglycan unusual lipids in cell membranes Nutrition: Auto or Heterotrophic What makes them unique: live in extreme environments (most will die if there is oxygen) Examples: methanogens, halophiles

Cell Type: Eukaryotic # of Cells: Unicellular Cell Characteristics: Generally don’t have cell walls Some have chloroplasts Nutrition: Auto or Heterotrophic What makes them unique: # of cells Examples: Paramecium, Ameoba, Volvox, Slime molds, Giant Kelp (seaweed), algae Domain: Eukarya Kingdom: Protista

Cell Type: Eukaryotic # of Cells: Mostly Multicellular Cell Characteristics: cell walls made of chitin (carbohydrate) Nutrition: Heterotroph What makes them unique: Involved with breaking down and recycling dead and decaying matter. Digest externally by secreting enzymes Examples: Mushrooms, Molds, Yeasts Domain: Eukarya Kingdom: Fungi

Domain: Eukarya Kingdom: Plantae Cell Type: Eukaryotic # of Cells: Mostly Multicellular Cell Characteristics: cell walls made of cellulose (carbohydrate) Nutrition: Autotroph What makes them unique: non- motile Examples: Mosses, ferns, flowering plants, trees

Domain: Eukarya Kingdom: Animalia Cell Type: Eukaryotic # of Cells: Multicellular Cell Characteristics: NO cell walls Nutrition: Heterotrophic What makes them unique: All motile Examples: sponges, cnidarians, worms, insects, mollusks, fish, amphibians, reptiles, birds, mammals

Summary of the Kingdoms