Question

In your own words, explain how fossil records of the past are reliable sources of information about evolution of life on Earth.

Answer 1

here is a reason that i hope you can put them into your own words, hope it helps :) :
the lower the layer, the older the crust. so the fossils in an area in each layer -starting with the lowest layer- show the evolution of that organism (which are usually the early ancestors of the current organisms in that area)