Classification of Life Chapter 17

How Classification Began ▫Classification-grouping objects or information based on similarities ▫Taxonomy- Branch of biology that groups and names organisms based on studies of their different characteristics ▫Aristotle’s System ( B.C.)  Everything was either a plant or an animal  System stood for centuries

Aristotle’s System- grouped by analogous structures

Linneaus’ system of Binomial Nomenclature  Based on physical and structural similarities (resulted in grouping that revealed relationships between organisms)  Explained evolutionary relationships  Uses binomial nomenclature- 2 word naming system  Genus- 1 st word, groups similar species  Specific epithet(SPECIES) describes the characteristics of the organism.  Humans: Homo sapiens where homo=genus, sapiens= wise (Greek)

Scientific vs. Common Names  Latin is language of taxonomists  Common names- common to area they are found. Example: Car Hood (USA) = Bonnet (Britian)  Flashlight (USA) vs. Torch (Britian)

Modern Classification: TAXONOMY Uses underlying evolutionary relationships as well as external and internal relationships How it works:  A framework (are dinosaurs more closely related to reptiles or birds?)  Useful tool- helps to identify unknown species  Helpful in Economy- Knowing pine trees contain a useful substance for disinfecting may lead to finding another disinfectant in a similar species.

TAXONOMIC RANKINGS Larger taxa- broad groups ie. Animal Kingdom Smallest taxa- more specific, organisms can interbreed and produce viable offspring.  Kingdom- largest division 6 total  Phylum- similar classes- in plant kingdom may call it divisions  Class- similar orders  Order- similar families  Family – similar genus  Genus- similar species  Species- most specific, can interbreed.

7 TAXA  Kingdom- largest division 6 total  Phylum- similar classes- in plant kingdom may call it divisions  Class- similar orders  Order- similar families  Family – similar genus  Genus- similar species  Species- most specific, can interbreed.

Problem solving lab 17.1

Determining Evolutionary Relationships 1.Structural similarities- may imply a shared ancestor. If you observe an unknown with retractable claws you will put them in the cat family. 2.Breeding behavior- may differentiate among species (ie. Hyla versicolor and Hyla chryosocelis) 3.Geographical Distribution- Location of the species on the Earth.

Evolutionary relationships cont… 4. Chromosome Comparison  Banding in metaphase 1  Size of chromosomes  Position of the centromere 5. Biochemistry  DNA sequences  Proteins found  Nucleotide sequences

Phylogenic Classification Models PHYLOGENY- evolutionary history of an organism. Species with the same ancestor, share and evolutionary history. ▫Cladistics  System of classification based on phylogeny  Assume organisms diverge from a common ancestral group.  CLADOGRAM (fig 17.7) – model of phylogeny of species. Similar to a family pedigree

CLADOGRAM Velociraptor Archaeopteryx Robin Light bones 3-toed foot; wishbone Down feathers Feathers with shaft, veins, and barbs Flight feathers; arms as long as legs Theropods Allosaurus Sinornis

Phylongeny cont… ▫Fanlike Model (fig 17.8)- Give more information than a cladogram  Phylogeny  Time  Extinction  Anatomy  Genetics  Etc… 6 kingdoms: Eubacteria, Archaebacteria, Protists, Fungi, Plants, Animals

Six Kingdoms of Organisms Arranged based on: 1. Organization (uni/multicell) 2. How they obtain energy or eat.(heterotroph, autotroph) 3. Prokaryotic or eukaryotic- complexity of cell structure.

Prokaryotes: ▫Prokaryotes: MONERANS  Microscopic  Unicellular  No distinct nuclei  Organelles are not membrane bound organelles. Heterotrophs or Autotrophs (may be photosynthetic or chemosynthetic

2 kingdoms of prokaryotes:MONERANS 1.ARCHAEBACTERIA- most live in extreme environments without oxygen. Example: ocean depths, swamp, volcano 2. EUBACTERIA species, strong cell walls, complex genetic make-up, most are harmless, some cause disease, for example,strep throat.

3. Protist kingdom- Eukaryotes  Eukaryotic but lack complex organ systems  Live in moist environments (pond scum)  Uni /multicellular  Plant like autotrophs  Animal like heterotrophs  Fungus like- heterotrophs with reproductive structures like fungus. Cilia Oral groove Gullet Micronucleus and macronucleus Contractile vacuole Anal pore

4.Fungus- earth’s decomposers  Heterotrophs that DO NOT move from place to place  Multicellular (except yeast)  Eukaryotic  Absorbs nutrients form organic material in environment  50,000 known species

5. Plants  Multicellular  Photosynthetic eukaryotes  Produce oxygen  Cell walls and chloroplasts typical  Mosses, ferns and evergrees  known species

6. Animals Multicellular consumers(heterotrophs) Nearly all mobile DO NOT have cell walls Organization: Cells  Tissues  organs  organ systems  organism