Final answer:
Gene conservation is not a result of gene duplication but indicates the maintenance of a gene's function across species; while sub functionalization, pseudogenes, and neofunctionalization are possible outcomes after a gene duplication event.
Step-by-step explanation:
Regarding gene duplication, it is important to note that several outcomes are possible from this process. Subfunctionalization occurs when each duplicate gene retains a part of the original gene's function. Pseudogenes are duplicated genes that are non-functional due to mutations. Neofunctionalization happens when a duplicate gene develops a new and different function from the original. Gene conservation, however, is not a result of gene duplication but rather the preservation of gene function across different species over time, often due to the evolutionary importance of a gene.
Therefore, the correct answer is: 4) gene conservation - as this is not a result of gene duplication but a feature denoting the importance of a gene's function that is maintained consistently through evolutionary history.