"If I descended from an ape, how come apes are still here?"

I too was perplexed as to how to answer this question. My fiance and her mom don't hold evolution in high regard. I tend to be a person who tries to respect my elders/parents (In this case soon to be In-Law), and when she heard I ascribed to the idea of evolution she asked the question mentioned by the O.P.I tried to explain it as best I could as:
Evolution isn;t a process by which creatures become more perfect or intelligent and their previous generational forms become obsolete and die off. Instead evolution molds creatures to become best adapted to their environment through generations making subtle changes.I was at a loss as to how to address it without coming off condescending or aggressive towards their views.
(Also, first post here. Hello everyone)