You will be given a definition of a task first, then some input of the task.
In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

Snake venom evolved by the duplication of a gene encoding for a normal regulatory or bioactivity protein .
Output:
Snake venom has been shown to have evolved via a process by which a gene encoding for a normal body protein , typically one involved in key regulatory processes or bioactivity , is duplicated , and the copy is selectively expressed in the venom gland .