Constructing Cladograms

Do Now Constructing Cladograms Key Question: What does a family tree tell you? Initial Thoughts:

Evidence: Notes & Practice W.S. Cladograms are diagrams that show the relationship among organisms based on traits. Example: # of shared characteristics

Some Look Different

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Cladogram #1: 1 st, Look at the traits LanceletLamprey Eel TunaSalamandarLeopard hair0000X eggs0000X 4 legs000XX jaws00XXX vertebrate0XXXX

Then, construct the tree Find the most ancestral (has the least # of shared characteristics) species and put it at the bottom. Then add the species as they have more shared characteristics

What species are most closely related? The least? With what species does the Salamander share a common ancestor? Check yourself:

Cladogram #2 Construct a tree for the following species:

FeatherLungsFur & Mammary Glands Claws or Nails Jaws Pigeon Perch Mouse Lizard Chimp Hagfish Salamander

Feathe r LungsFur & Mammary Glands Claws or Nails Jaws PigeonXX0XX4 Perch0000X1 Mouse0XXXX4 Lizard0X0XX3 Chimp0XXXX4 Hagfish Salamander0X00X2

HumanCatFishKangarooFrogBird Backbone Live birth instead of hatching from an egg Formamen magnum under skull – head sits on top of spine, not in front of spine (upright posture) At least one pair of LEGS Pairs of appendages (legs, fins, flippers, etc.) Mammary glands Placenta and umbilical cord instead of pouch for baby Embryo protected from drying out (hard egg shell or develops inside of the mother) #3 Vertebrate Cladogram

HumanCatFishKangarooFrogBird Backbone x xxxxx Live birth instead of hatching from an eggxx0x00 Formamen magnum under skull – head sits on top of spine, not in front of spine (upright posture) x00000 At least one pair of LEGSxx0xxx Pairs of appendages (legs, fins, flippers, etc.) xxxxxx Mammary glandsxx0x00 Placenta and umbilical cord instead of pouch for baby xx0000 Embryo protected from drying out (hard egg shell or develops inside of the mother) xx0x0x #3 Vertebrate Cladogram

Analysis Questions 1.In cladogram #2, which 2 animals are the most closely related? Why? 2.Why is using a cladogram important for scientists who study evolution? 3.In the vertebrate diagram, all of these animals share a common ancestor. Based on the tree or cladogram, what characteristics would the ancestor organism have?

Summary What did you think about how scientists show relationships between species before this lesson? What did you learn about how scientists show relationships between species from this lesson? (Minimum of 3 sentences!!!) What are some further thoughts or questions you have about how scientists show relationships between species?

Reflection A recent expedition to the rain forest in Peru has discovered two new species: a skinny tailed squirrel and a blue-green robin. Redraw the Vertebrate Cladogram and place these animals in the tree. Using complete sentences, explain why you placed the animals in those spots on the tree.

Big Idea

Rate My New Knowledge on the Learning Target 0 – I don’t understand 1 – I have some knowledge 2 – I understand the learning target well 3 – I understand the learning target well and I can teach someone else about it If you scored less than 2, explain what you can do to meet this standard