Fossil Record - Provides proof by exposing the details of a ancestor for compared to the living one.
Geographical Distribution of Living Things - a pattern of the ancient existing species, isolated land and islands have their own species of plants and even some animals.
Similarities in Development - Charles Darwin used the science of embryology to test many species within a class to find out that they are similar even if the adult version looks completely different.
Molecular Similarities - its believed that natural selections isn’t the reason for evolution actually its the genetic drift of mutant alleles that are neutral.
I hope this is good