Classification of Organisms What is the goal of biologists who classify living things?

Species of Organisms There are 13 billion known species of organisms This is only 5% of all organisms that ever lived!!!!! New organisms are still being found and identified

What is Classification? - Classification is the arrangement of organisms into orderly groups based on their similarities - Classification is also known as taxonomy - Taxonomists are scientists that identify & name organisms

What is the common name of this animal?

Common Names

Binomial Nomenclature Developed by Swedish botanist – Carolus Linnaeus Each species assigned a two part name 1 . Written in italics 2. First word is capitalized and is organisms Genus – group of similar species 3. Second word is species – group of individuals capable of interbreeding and producing fertile offspring

Dichotomous Keys -Used to identify organisms based on visible characterstics/structures -consists of a series of paired statements/questions that describe alternative possible characteristics of an organism -statements describe presence or absence of certain visible characteristics/structures of the living organism

Dichotomous Keys

Systematics - A way to organize living things into groups (or taxa) that have biological meaning

QuickLab Classifying Fruit Look at the five different types of fruit given to your group. Examine the structure of the fruit (external and internal) 3. Construct a table with 5 rows and 4 columns. Label each row with the name of the different fruit. 4. Examine the fruits that help you tell the fruits apart. Label the columns in your table with the names of these characteristics. 5. Record a description of each fruit in the table. 6. Based on your table, which fruits most closely resemble one another? 7. Create a dichotomous key for the different types of fruit.

Linnaean Classification Systems Includes seven taxa: Species Genus Family – several organisms of the same genus that share many similarities Order – closely related families Class – similar orders Phylum – organisms that are different but share important characteristics Kingdom – includes all multicellular animals Domain

Domains Broadest, most inclusive taxon Three domains Archaea and Bacteria are unicellular prokaryotes (no nucleus or membrane-bound organelles) Eukarya are more complex and have a nucleus and membrane-bound organelles

Domain Eukarya is Divided into Kingdoms Protista (protozoans, algae…) Fungi (mushrooms, yeasts …) Plantae (multicellular plants) Animalia (multicellular animals)

Protista Most are unicellular Some are multicellular Some are autotrophic, while others are heterotrophic Aquatic

Fungi Multicellular, except yeast Absorptive heterotrophs (digest food outside their body & then absorb it) Cell walls made of chitin

Plantae Multicellular Autotrophic Absorb sunlight to make glucose – Photosynthesis Cell walls made of cellulose Growth, with increases in size and number of cells, is part of development. Development involves many stages from conception until death.

copyright cmassengale Animalia Multicellular Ingestive heterotrophs (consume food & digest it inside their bodies) Feed on plants or animals copyright cmassengale

copyright cmassengale

Domain Archaea Kingdom - ARCHAEBACTERIA Probably the 1st cells to evolve Live in HARSH environments Found in: Sewage Treatment Plants (Methanogens) Thermal or Volcanic Vents (Thermophiles) Hot Springs or Geysers that are acid (thermoacidophiles) Very salty water (Halophiles)

Domain BACTERIA Kingdom - EUBACTERIA Some may cause DISEASE Found in ALL HABITATS except harsh ones Important decomposers for environment Commercially important in making cottage cheese, yogurt, buttermilk, etc.

Modern Evolutionary Classification Phylogeny – evolutionary classification Goal is to group species into larger categories that reflect lines of evolutionary descent rather than overall similarities and differences Clades – a group of species that includes a single common ancestor and all descendents of that ancestor (living and extinct) Monophyletic because includes a single common ancestor

Cladogram - Links groups of organisms by showing how evolutionary lines branched off from common ancestors Amnion

How to create a cladogram

Derived characters – a trait that arose in the most recent common ancestor of a particular lineage and was passed along to its descendants

Amnion Amnion

Constructing a Cladogram Identify the organism in the table that is least closely related to the others. Use the information in the table to construct a cladogram of these animals Backbone Legs hair earthworm Absent absent trout Present lizard human present

Constructing a Cladogram What trait separates the least closely related animal from the other animals? Do you have enough information to determine where a frog should be placed in the cladogram? Explain your answer. Does your cladogram indicate that lizards and humans share a more recent common ancestor than either does with an earthworm? Explain your answer.

DNA in classification Similarities and differences in DNA are used to develop hypotheses about evolutionary relationships The more derived genetic characters two species share, the more recently they shared a common ancestor and the more closely they are related in evolutionary terms DNA is used to make relationships more accurate Used when anatomical traits cannot provide a clear ancestor

1. 2. Hair Legs Thumbs Eyes Human Snake Monkey Mouse Starfish 5 Fingered hand; claws Fur, milk Placenta; live birth Retractable claws Bear Lion Lizard Platypus Tiger Zebra