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: Macroevolution is evolution over geologic time above the level of the species. 
Fact 2: Besides the above-named species, various other species of the genus have been used medicinally.
Macroevolution is evolution over geologic time at the genus level and above.

Fact 1: a greenhouse is used to protect plants by keeping them warm. 
Fact 2: Another well known plant is the Mesquite Bush.
a greenhouse is used to protect bushes by keeping them warm.

Fact 1: Bladder infections can be treated with antibiotics prescribed by a doctor. 
Fact 2: Antibiotics are drugs used to kill bacteria.

Bladder infections can be treated with bacteria-killing drugs.