How are derived characteristics used to determine evolutionary relationships?

Trough connections between pieces of evidence

Explanation:

The first thing that scientists have to do is to collect valid pieces of information of some organism, human or animal.

Then, collected information is being compared and then the scientists are making an evolutionary connection.

For the identification of homologous structures, they are using molecular data or morphologic data.  

a. he allowed the people he conquered to keep their customs and religions.

he captured babylon and freed the jewish people to return to judah.