Combine the given two facts to write a concluding fact. Note that there should be some parts of the first and second facts that are not mentioned in this conclusion fact. Your combined fact should be the result of a chain between the two facts. Chains form when two facts connect together to produce a concluding fact. An example of a chain is: "pesticides cause pollution" (fact1) + "pollution can harm animals" (fact2) → "pesticides can harm animals" (conclusion fact). Parts of the concluding fact overlap with the first and the second fact. To construct such a  concluding fact, a useful way is to borrow the subject from one fact and the ending conclusions from another fact.

Fact 1: Pedigrees are useful tools for studying inheritance patterns. 
Fact 2: Pedigree charts are a graphical way to represent the ancestry of an individual.
charting ancestry on a graph is a useful tool for studying inheritance patterns.

Fact 1: tectonic plates being pushed together causes earthquakes. 
Fact 2: Plumbing is sometimes damaged during an earthquake.
Tectonic plates being pushed together can damage plumbing.

Fact 1: magnetism can cause objects to repel each other. 
Fact 2: Magnetism is the force where objects are attracted or repelled to one another.

magnetism is the force that causes objects to push or attract each other.