 For hundreds of years people have been trying to classify the species on our planet Earth  There are potentially hundreds of thousands new species still waiting to be discovered  With the discovery of new species classification of organisms is constantly being modified  The goal is to track evolution and determine which organisms share common ancestors

 A simple system of naming organisms allows anyone in the world to discuss the same creature regardless of its common name  For example....

 But, Carolus Linnaeus calls him.... Melanoplus femurrubrum

 Linnaeus classified organisms according to their structural similarities: this is called TAXONOMY  Each group to which Linnaeus assigned organisms is called a TAXA (singular is TAXON)  Modern taxonomy groups organisms based on their evolutionary relatedness: this is called PHYLOGENY  Organisms share common ancestry if they show similar stages of embryological development and anatomical structures.

 The 18 th century Swedish naturalist Carolus Linnaeus simplified the system of naming and classifying organisms  The system, known as binomial nomenclature is still in use today!  What are the two parts?! Let’s find out

Kingdom Phylum Class Order Family Genus Species Animalia Chordata Mammalia Primates Homonidae Homo sapiens

 Note that the first name describes its similarity to other organisms while the second describes its uniqueness

 The taxon “species” is the smallest group and it contains only a single type of organism.  The organisms in a species are most like one another—except for sexual or growth stage differences, the individuals of a species have the same body or physiological morphology.

 Organisms in the same species can interbreed to produce viable offspring.

 These cannot....

 Similar species are grouped in the same genus  Example: the bobcat and the housecat are in the genus Felis

 Genera are grouped to form families. This group’s family is Felidae

 Families are grouped into Orders. These organisms are in the order Carnivora

 Orders are then placed in Classes. These organisms are in the class Mammalia

 Classes are grouped into Phyla. These organisms are in the phyla Chordata in the Kingdom Animalia

 Archaebacteria  Eubacteria  Protista  Fungi  Plantae  Animalia

 The largest subdivision of the animal kingdom are called the phyla!  Phyla represent different body plans and alternate ways of living  Let’s look at major phyla!

4500 Species Sponges are very primitive animals. Their cells show slight specialization and makes a fibrous supporting skeleton

9000 Species They are radially symmetrical animals, with the mouth at one end.. Many of the tentacles have specialized stinging structures (cnidocytes) that are sometimes poisonous, for defence. Examples include the hydra, sea anemones, corals, sea fans and the jellyfish (2:25 min)

9000 Species Animals that are bilaterally symmetrical and triploblastic (composed of three fundamental cell layers) are the Platyhelminthes, the flatworms. Flatworms have no body cavity other than the gut and lack an anus. Flukes, planaria and tapeworms are examples. ZnGo

Species Roundworms are found in nearly all habitats. They are small and unsegmented and often parasitic. Examples include the pinworm and heart worm.

Species Mollusks have a mantle, which is a fold of the outer skin lining the shell, and a muscular foot that is used for motion. Many mollusks have their mantle produce a calcium carbonate external shell. Members are clams, snails, octopus, and squid. d_EQ oxUMAy8

9000 Species Annelida is a group commonly referred to as segmented worms, and they are found worldwide from the deepest marine sediments to the soils in our city parks and yards. Both polychaetes, earthworms and leeches are members of this phylum.

~ Species Arthropods are characterized by the possession of a segmented body and jointed appendages. Members of this phylum have exoskeletons made of the polysaccharide chitin. Members include crustaceans, sow bugs, arachnids, mites, ticks and insects.

5500 Species Echinoderms evolved from animals with bilateral symmetry. Echinoderms' larvae are ciliated free-swimming organisms. Members include the sand dollars, sea urchins, sea cucumbers and starfish

Species They are united by having, at some time in their life, a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a muscular tail extending past the anus. Members include fish, birds, reptiles, mammals, and amphibians

 Dichotomous classification keys are used to help place organisms into the appropriate classification group  Classification keys include two choices for each characteristic

 Task: Pick about ten people in your class and create a dichotomous key to classify them  A teacher who doesn’t know the students in this class should be able to correctly identify you using your dichotomous key!