history of life as documented by fossils, the remains or imprints of organisms from earlier geological periods preserved in sedimentary rock.

This is an example of:

:the variety of life in the world or in a particular habitat or ecosystem.

the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock

This picture is an example of:

(of a species, family, or other group of animals or plants) having no living members; no longer in existence.

a change or the process of change by which an organism or species becomes better suited to its environment.

Which rock layer is the oldest?

Anatomical means relating to the structure of the bodies of people and animals

means having descended from one ancestor.

Which organism is the common ancestor?

a taxonomic group of any rank, such as a species, family, or class

 the science that deals with the earth's physical structure and substance, its history, and the processes that act on it.

What are photos like this evidence of?

the branch of science concerned with fossil animals and plants.

the comparative study of the body structures of different species of animals in order to understand the adaptive changes they have.

the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.

Which two are the closest related?

the process through which species adapt to their environments. It is the engine that drives evolution. 

because people (instead of nature) select which organisms get to reproduce.