12 Biology by BISM Academy
9 – Evidences of evolution (Fossils Record)
The Fossil Record:
Fossils are either the actual remains or traces of organisms that lived in ancient geological times. The organism may be embedded in sand, resin or ice, or an impression or cast
Is made of the body parts,
The tissue being replaced or petrified by silica or calcium carbonate minerals. Most fossils are found in sedimentary rocks.
Fossils as Evidence.
The succession of fossil forms is strong evidence in favour of evolution. It provides a visual record in a complete series showing the evolution of an organism.
Prokaryotic Fossils.
For instance, evidence from biochemistry, molecular biology, and cell biology places prokaryotes as the ancestors of all life, and predicts that bacteria should precede all eukaryotic life in the fossil record. Indeed, the oldest known fossils are prokaryotes.
Vertebral Fossils.
Another example is the chronological appearance of the different classes of vertebrate animals in the fossil record. Fossil fishes, the earliest vertebrates, with amphibians next, followed by reptiles, then mammals and birds. This sequence is consistent with the history of vertebrate descent. Example. The evolution of horse provides an example of such a history.