Cladogram Worksheet - Social Studies

Organisms with Lungs

• Five organisms identified to have lungs: Salamander, Lizard, Pigeon, Mouse, Chimp.
• All these organisms are positioned above the "Lungs" line on the cladogram.

Shared Characteristics

• Salamanders and mice both possess lungs and jaws, indicating a shared evolutionary trait.

Mammary Glands

• The mouse and chimp are noted for having fur and mammary glands, highlighting their classification as mammals.

Jawless Organism

• The hagfish is identified as the only organism lacking a jaw, emphasizing the diversity of jaw structures among vertebrates.

Claws and Nails

• Lizards and pigeons are characterized by having either claws or nails, illustrating some anatomical similarities.

Closest Relatives

• The most closely related pair of organisms on the cladogram is the perch and salamander due to their adjacent placement.

Amniotic Eggs

• Organisms that lay amniotic eggs include lizards and birds, a trait that has implications for their reproductive strategies.

Molting Exoskeletons

• Lobsters and spiders are capable of molting their exoskeletons, a crucial process for growth in arthropods.

Organisms with Lungs

• The organisms that have lungs include founder, lungfish, lizards, birds, and mammals, showcasing evolutionary adaptations.

Spiny-rayed Fins

• The perch and flounder are the two species characterized by spiny-rayed fins, relevant for their identification in aquatic systems.

Shared Characteristics of Lizards and Birds

• Lizards and birds share several characteristics: claws, amniotic eggs, lungs, vertebrae, and the ability to see UV light.

Closest Relationship of Lizards and Birds

• Lizards and birds are closely related according to their proximity on the cladogram, suggesting a shared evolutionary lineage.

Reading a Cladogram

• A cladogram can be read by noting that all organisms above a characteristic line share that trait, indicating their evolutionary relationships.

Law of Superposition

• Defines the concept that in layered soil deposits, the younger layers are positioned on top of older layers, providing a framework for understanding geological time.