A Question in the context of Evolution

On Facebook, a person made a post on his own wall about the evolution of the living world. At one point in the post, it was written that if for some reason the deer population increased excessively, it would create a shortage of plants. Therefore, just as an algorithm corrects errors, nature also would restore that balance by increasing the number of predators or through some other means.

While commenting on that post, I quoted this section and made a comment. My comment was: "But the question is, if nature is a blind, unconscious force, how can that blind, unconscious force understand that an increase in deer will create a shortage of plants? Thus, how does it know it must restore that balance by increasing the number of predators or through some other means?"

The person who made the post replied that no conscious intelligence or thought is required to maintain this balance of nature, because according to him, it is the result of a completely automatic cause-and-effect relationship. Giving an example, he said that just as in the case of a room AC, when the temperature rises, the AC cools by itself without any prior planning, similarly, when deer increase, tigers get ample food. As a result, the number of tigers also increases, automatically restoring the balance. Therefore, he believes that rather than considering it a conscious decision, it should be viewed as a perfect mathematical feedback loop.

I wrote in reply: "You gave a wrong example. Because the AC machine is pre-programmed by humans. Who is nature pre-programmed by?"

The post author then wrote that there is human programming behind making an AC, but there is no evidence in favor of the claim that someone programmed the universe. He said that this complex mathematical balance was born as a result of the automatic interaction of natural selection and blind physical laws operating over millions of years. Therefore, according to him, no external planner is needed here.

I wrote this time: "True, there is no proof. But plant numbers have decreased, and deer numbers have increased, so tiger numbers must now be increased—this cannot happen on its own. Who, where, and how is sensing that the deer population has increased, so the tiger population must be increased now?"

Now the post author wrote that an increase in deer ensures sufficient food and nutrition for tigers, which naturally increases their reproductive capacity and cub survival rates. So he believes no one sits down to calculate or sense anything to increase tiger numbers; rather, the abundance of food automatically creates this balance.

This time I wrote: "Suppose there are plants and deer, but there are no tigers in the scene. In this situation, the deer population will skyrocket, and plant numbers will decrease. In this state, how can blind, unconscious nature sense that now tigers must be brought into the scene, otherwise ecological balance cannot be maintained?"

This time, no further answer was received from the post author. He went quiet.

However, someone else replied. He wrote that a food crisis would then arise, and if there were a lack of food, the deer population would automatically decrease.

I wrote in reply: "If the deer population automatically decreases, then with fewer deer, plant numbers will increase again. As plant numbers increase, deer numbers will increase again. As deer numbers increase, plant numbers will decrease again. This will keep going in cycles. So, there seems to be no need to bring tigers into the scene to maintain natural balance."

He then replied that in a forest where tigers exist, tigers will accelerate this process and become part of that ecosystem.

I replied: "If the ecosystem can protect itself without tigers, why would tigers need to arrive at all to protect the ecosystem? Thus, the logic behind the arrival of tigers is not clear."

This time, no reply came from him either.

That means, in the end, no answer was found to my question: where there are only plants and deer, how can blind, unconscious nature understand that natural balance cannot be maintained unless tigers are brought into the scene? And if nature can protect its ecosystem without tigers, why would there be any need to bring tigers to save the ecosystem?

However, if it happened that deer and tigers arrived simultaneously, there is no problem at all. But if it happened that deer came first, and tigers came later, only then does the problem arise. How was the need to bring tigers realized?