A and D are almost entirely solid solid
Answer AND Explanation:
Darwin describes natural selection as a process whereby nature selects those organisms that have favourable characteristics to be parents of the next generation. The individuals possessing the favourable traits are better suited to the prevailing environmental conditions. This enables them to stand a better chance to survive in the struggle for existence due to limited resources.
Organisms on earth live in the Biosphere
Answer: The food chain
Explanation: It is important to have a large number of producers and herbivores in an ecosystem because of the food chain. Without producers the herbivores would have no food. and without the herbivors the carnivores would have no food.