1. natural selection acts on existing traits because you can not evolve into something you didn't have
2. original structures evolve to accomplish new function in order to survive
Meiosis is the splitting of haploid gamete cells (Sperm and Egg)
73130-26, S62.323A, W51.XXXA, Y93.61 that should help.
Because the gravity of the sun keeps all planets in their orbits :3 hope I helped