The third argument presented by atheists is based on the theory of evolution which, they claim, shows that everything in our world has not always been as it is. Instead, initially it was in a primitive state and gradually evolved to its present state, adapting to environments with the passage of time. The species that failed to adapt to their environments became extinct. From this, they conclude that there is no inherent plan or design in this universe and that it all happened by chance.
We have already refuted this argument in principle. It should be kept in mind that the extinction of some species because of their failure to adapt to the environment and gradual adaptation of the others does not prove that the world is without a plan or design. On the contrary, extinction of some species and survival of the others denotes an underlying wisdom and proves that there is a design and final cause for this universe and purpose of life. It indicates that the Creator of this universe is constantly pruning His garden and trimming the trees therein. He cuts down the branches and plants that are weak to allow for the progress of a stronger tree and removes weaker trees so they do not hinder the progress of the stronger ones.
One might argue that if God knew that a particular branch or tree of this garden of the universe is weak and unable to fulfil the purpose of its creation, why did He create it in the first place? God did indeed create everything with a particular purpose to fulfil. However, when it develops a defect and cannot keep pace with others and fails to fulfil the purpose of its creation, it is dropped in accordance with the law of nature. Both laws are made by God. One, that God creates everything with a specific purpose and He wants it to fulfil the purpose. Second, when something is adversely affected and fails to fulfil its purpose, it is destroyed. For instance, God created man for spiritual and physical progress but because of their misdeeds, some do not fulfil the purpose and are thereby cut off like dry branches.
It should also be born in mind that according to the law of nature, the sole purpose of some species is to support others in their growth for a limited period. Once the latter are firmly established and have attained their perfection, the supporting species are rendered extinct. Farmers sometimes grow ‘fillers’ around some plants to protect them and enhance their growth. Once the plants become strong, the fillers are destroyed for they have fulfilled their purpose and their preservation thereafter may prove harmful for the plants.
Science further shows that the death of certain organisms provides life and sustenance for the others. The sole purpose of their creation is to die and give birth to life and growth of others. There are countless other examples to demonstrate that the extinction of some species after a time, and survival and growth of the others, does not disprove the existence of God. What it does prove is that there is a Conscious, Wise and Omniscient Being who has the capacity and wisdom to run this universe toward a particular goal. Someone may yet ask: If the weak are destroyed and only the strong survive in accordance with the law of nature, then where is the Hand of God? I maintain that we do not deny the laws of nature and we do believe in this law of cause and effect, but these do not disprove the existence of God. As already elaborated, the system of cause and effect itself points to a Higher Being and constitutes another evidence for the existence of God. I would like to reiterate that the theory of evolution as postulated by Darwin is not an established scientific fact. Some of its details have been disputed by many other scientists and the theory in its present form has been totally rejected.