Why do offspring produced by asexual reproduction show no variation from the parent?

Because it has the same exact genes as the parent. Unless a mutation is shown. The two daughter cells are identical to the parent because there is no other second parent to cross genes with

Explanation:

lizards have adapted to life in the desert. some desert lizards have toes with spiny scales to them run across the sand without sinking. some use the sand to hide from predators, or to search for small animals that they prey upon.