Packet 12: Classification Notes: pg. 6 and pg. 8-9

Ways to Show Evolutionary Relationships: pg. 6 Phylogeny- Classifying organisms based upon their evolutionary relationships. Phylogenic tree is a diagram that looks a bit like a family tree, showing who the nearest relatives were and who shared a common ancestor and when.

Phylogenic Tree

Phylogenic Tree

Ways to Show Evolutionary Relationships Cladogram- A chart that shows phylogenic (evolutionary) relationships between organisms.

Cladograms Each of these creatures has an evolutionary relationship to one another. They all share a common origin, and their current forms are all derived from branching events somewhere in the phylogenetic past.

Use the cladogram to answer the following questions: What features are shared by the salamander and mouse? Jaws and lungs Does the hagfish possess a jaw? No Why is the derived characteristic ‘feathers’ not written on the main axis like all of the other characteristics? B/c they are only possessed by the birds

Cladograms A cladogram can be constructed for any group of organisms. Use the cladogram below to determine which characteristics are found in the: kangaroo, earthworm, amoeba, lizard, cat, sponge and salmon. (+ = present; - = not present) Limbs

What traits do each organism have? Kangaroo- segmented body, jaws, hair, multicellular, limbs Earthworm- segmented body, multicellular Amoeba- n/a Lizard- segmented body, jaws, multicellular, limbs Cat- segmented, jaws, hair, placenta, multicellular, limbs Sponge- multicellular Salmon- segmented body, jaws, multicellular

Classification Keys A classification key, also known as a Dichotomous key, is useful in identifying unknown organisms (but is not limited to being used with living things). Begin on line 1 (reading choices a and b). Choose the statement that matches your organism. Follow the Go To direction until you come to a line that identifies the organism by name.

Pinus ponderosa Monodon monoceros Passer domesticus Ophiophagus hannah

Pg. 9 Terms to keep in mind: Serrate or “sawtooth” edge Now Try it Yourself! Terms to keep in mind: Notched or lobed leaf Serrate or “sawtooth” edge

White elm English oak Magnolia Sweet gum tree

Using the above dichotomous key- what can you tell me about the sugar maple? Work backwards: Leaf wider than it is long Each lobe having several points Leaf not star shaped Five pointy lobes Four of five lobes total Leaf deeply notched or lobed