Paleontology (study of fossils)
Fossils- simpler organisms found in oldest rocks, more complex found in recent rock- live on earth is gradual unfolding from simpler to more advanced organisms.
Transitional forms (TF) = features common to two know groups: e.g.
Early to modern day horses: Eohippus (Early)- small, four toes, normal cheek. Modern horses have large cheek and one toe.
TF- three toes, medium cheek
Reptiles to birds : Archaeopteryx ( flying dinosaur with wings) reptile= teeth, bones, claws birds= feathers, wings
Fish to amphibians: Lobe thinned fish has bones in its fins suggesting it could walk on land