Question

question 2
the presence of allows species to evolve.
siblings
competition
resources

Explanation:

Evolution is driven by changes in genetic material. Variations in DNA (such as mutations) provide the raw material for natural selection. Siblings are just individuals within a family group. Competition (for resources like food, space) acts on existing variations but doesn't create the basis for evolution. Resources are what organisms compete for, but again, don't directly allow species to evolve. Only variations in DNA (which can lead to new traits) are the fundamental factor that allows species to evolve over time through processes like natural selection.

Answer:

variations in DNA