Fossils are considered essential for the study of biological evolution because they are important in creating a time frame for once living organisms. They are the only specimen that provide us with direct physical evidence of the existence of past life as well as showing us the proof of evolution through the changes of each fossil’s skeletal structure. Sometimes interpreting the sequence of evolution within a living creature is difficult as the full range of fossils may not have been found, meaning that we may not have been able to see the entire evolutionary process. Phylogeny, which is the biological change and evolutionary relationships is documented through the place of fossils in time. There are two main ways out finding out how old something:
