It has been awhile since anyone asked this.
This question is used as an example of the most utterly, obviously stupid questions that creationists ask. If one had the very tiniest amount of a clue about what the evolutionary model was about and one thought for just a small moment it would be obvious that this is very, very dumb.
I'm sure you have been given this question by some preacher or another member of the CCOI-tm by Jar ( Christian Cult of Ignorance) as a supposed killer of Darwinism.
If so you should reject such as individual or organization of a source for any of your ideas. They are either deliberately lying or utterly and willful ignorant.
The answer is derivable from:
If your parents have children how come they are still around and/or if you exist do your cousins have to die?
Try it and see. If you can't get it from that clue then you are too abysmally dumb to be able to understand anything discussed here and you might as well leave.