Comparative Study – Five Classes of Vertebrates
The wall charts of the five vertebrate classes ( or one set of function labels from one of the classes) . The names fish (or Pisces), amphibian, reptile, bird ,, and mammal on the side going down.
Have a group of children lay out the loose pictures of the fish in order of their function. Next a group of children can lay out the pictures of the amphibian, then the reptile, then the bird, then the mammal.
The elements are compared, discussing the characteristics of each class and how this contributes to the evolutionary process.
Example: The fish lay many eggs in the water and the young when they are born are abandoned. The same is true for the amphibians. The adult who lives on land, returns to the water to lay many eggs. The young are abandoned and live for a time in the water.
The reptile also lays eggs and abandons them. But reptiles are land animals, so their eggs are laid on land. A damp environment is needed for the egg, so Nature put water inside the egg and a hard shell on the outside. The mother sometimes leaves the eggs on the sand to warm.
With birds, we see the first real caring for the young. The male and female sometimes build a nest together where the eggs are laid. The female keeps the eggs warm by sitting on them. When the eggs hatch, the male or the female goes to find food for the young. The young are taught how to search for food and to escape danger. The mammals do not lay eggs. The female keeps the egg inside her body and the young are born alive. The female cares for the newborn, and changes some of the blood into milk to feed it.
Aim: To examine the process of evolution through animal characteristics. To give children a sense of the process scientist go through in classification).