Does it make sense to make lactase if
there is no lactose present?

However, because lactose-free milk contains added lactase, it's easier to tolerate for those with lactose intolerance, making it a good alternative to regular milk. Lactose-free milk is easier to digest for people with lactose intolerance because it contains lactase, the enzyme used to break down lactose.

Explanation:

hope i helped :)

they each offer a fresh glut of resources to the organisms that can arrive and exploit them. as individuals and new species continue to appear, they actively and passively alter the environment. competition for shared resources increases, local abiotic and biotic conditions shift, and the relative abundances of species change accordingly. the process is called ecological succession, and it is one of the earliest and most well-known concepts in ecology.

your answer is "the 1950's"