I want to know the answer to the following question:
What is one primary source of orphan protein-coding genes?
All the background I'm provided with is that "Two primary sources of orphan protein-coding genes are gene duplication followed by extremely rapid sequence change, such that the original relationship is undetectable by sequence comparisons, and formation through mutation of "cryptic" transcription start sites that introduce a new open reading frame in a region of the genome that did not previously code for a protein.". Is that enough to answer the question?
Answer: yes