Evidence for Evolution: Fossils and Comparative Anatomy

What are the different pieces of evidence of evolution over time?

Fossils

show the evolutionary change throughout time

How can we tell how old a fossil is?

radioactivity

by comparing the ratio of radioactive element to the decay product, radiometric dating can provide an age estimate

progressive series: fossils that have remains of species ancestral to modern species

intermediate species: stages passed through and eventually culminate with a modern species that is clearly related to ancestors

Comparative Anatomy with descendants

a comparison of the anatomy of organisms of different species can reveal similarities that can only be explained by shared ancestry