CHAPTER 18 - CLASSIFICATION

CLASSIFICATION & IDENTIFICATION Taxonomy- science of classification

1. Classification-assigning organisms to a taxa based on similarities

2. Nomenclature- rules of naming 3. Identification- determining belonging

Important for: sense of relationships, past to present enhance communication- Doctors & scientists make predictions about similar organisms

CAROLUS LINNAEUS Species-similar organisms that can interbreed

Didn’t work well for asexual organisms- called strains Linnaeus divided into plantae & animalia only

Taxon- group or level of classification Kingdom, Phylum, Class, Order, Family, Genus,

Species King Phillip Came Over For Good Spaghetti

The more of these that they have in common, the more closely related they areEx: Ursus arctos (grizzly bear) Ursus maritimus (polar bear)Ailuropoda melanoleuca (Giant panda)

Who is more closely related?

BINOMIAL NOMENCLATURE- 2 PART NAMING use Genus & species

Latin names Genus-noun, written first, capitalized Species- adjective, lowercase *both written in italics or underlined

Ex: Diplococcus pneumoniae or Homo sapiens

PROBLEMS WITH COMMON NAMES1. They don’t tell how organisms are related2. Misleading3. Vary from place to place

PHYLOGENETIC TREES diagram that depicts the lines of

evolutionary descent of different species, organisms, or genes from a common ancestor

EVOLUTIONARY CLASSIFICATION Based on: 1. Phylogeny- evolutionary history

Modern day vs fossil record 2. Developmental stages- egg, larva, etc. 3. Biochemistry- DNA 4. Behavior- mating rituals, breeding

seasons, calls

SYNAPOMORPHY- A SHARED, DERIVED CHARACTER The more recently two species diverged from

a common ancestor, the more synapomorphies they will share.

Unique synapomorphies found only in a single group provide strong evidence for the common ancestry of members of that group.

THE SYNAPOMORPHIC ASTRAGALUS ANKLE BONES OF WHALES (CETACEANS) AND CLOVEN-HOOVED MAMMALS (ARTIODACTYLS) HELPED BIOLOGISTS DETERMINE THAT THESE TWO GROUPS SHARE A RELATIVELY RECENT COMMON ANCESTOR.

CLADOGRAMS Diagrams that shows the evolutionary

relationships among groups of organisms Uses derived characters- characteristics that

appear in recent parts of a lineage but not in its older members

  Vertebrae Bony Skeleton Four Limbs Amniotic Egg Hair Large Holes in Skull

Sharks X          

Ray-finned fish X X        

Amphibians X X X      

Primates X X X X X  

Rodents X X X X x  

Crocodiles X X X X   X

Dinosaurs & Birds x x x x   x

Construct a Cladogram

18-3 KINGDOMS & DOMAINS

Robert Whittaker- 5 kingdom system Plantae, Animalia, Fungi, Protista, Monera Did not address viruses

Today: 6 Kingdom System Monera> Eubacteria & Archaebacteria

WOESE- 3 DOMAINS Determined by rRNA sequencing

1. Archae- extreme bacteria 2. Bacteria- everyday bacteria 3. Eukarya- (Protista, Fungi, Plantae, Animalia)

CREATE YOUR OWN KEY: