How do fossils provide evidence about the evolution of life on Earth?
EXAMPLE : You got your basic layers deposited on the seabed. The top layers have fish and dolphin bones. The deeper you go, the simpler the fish bones look. Go down deep enough and eventually all you have are seashells and trilobite shells. The fossils are organized from top to bottom, more advanced to less advanced. Millions of fossils, found in well-dated sequences of rocks, show evolution of forms through time and show many transitions among species. The fossil record is unequivocal on the progression of life from simple beginnings to complex organisms. Animals without backbones predate vertebrates. Amphibians appear after fish, mammals appear after reptiles, and no complex life occurs in rocks nearly as old as those containing the oldest fossil bacteria.
