Seemingly endless length of time, the existing life developed from unicellular prokaryotic on extremely complex and diverse journey of the evolution, which existing life is influenced by the human species. We live in the absolute top of the food chain, we have no natural enemy. The human species is only and common emperor on each other species include all top predators on the land, in the sea and in the air, but we are not the strongest or fastest, we can not fly or breathe under the water, we have no best motion or sense system, we have no toxins, huge claws or teeth. So what is the overall winner ability?
Previously the general opinion was that the toolmaking (weapon) and applications leads to the ascension, the criterion was the two legs position for free hands and the opposable thumb. This was the process, but the flavor, which is the key role in the toolmaking, it is the human brain, the most advanced central nervous system in the nature and the main ability is the learning.
If we compare our brains with brains of other species, we can determine, that the structure is similar like other mammals. The most significant difference is in the size and weight. The size difference is due only to the mandibular muscle mutation. This weaker muscle enable to increase our back of skull and ensure the space for bigger and advanced brain. Approximately our skull grow continuously till 30 years old, but for example the chimpanzee skull stop in 3-4 years old, therefore they can not reach higher intelligence level than a child, the further learning is useless. After this, easy to see, that the 1.23% difference between the human and chimpanzee DNS and 5 millions years old divergence is enough to explain the visible differences.
However these differences are not so visible, if we exam only the ovum or the content of information.
The big, complex brain alone is not enough to obtain the knowledge, it is just a criterion, what open the possibility by learning. In the learning process, the communication, the ability of communication is very important and of course the remembering also. We don't know the limit yet, but we know really extreme performances.
However our brain is only 2% of our bodyweight, but the 1011 nerve cells (neurons) need a lot of energy: 15% volume of the heart arteries, 20% of total oxygen consumption and the human brain needs 0.1kcal per minute. In many species cases, a similar high energy demand means problem, for example it is observed, the brain of some kind of bats is reduced if we compare with ancestor. During evolution they invest more in maneuverability with increasing size of wings. As all, this process is also a conformation to the environment.
Previously we read a great example regarding the photosynthesis in plant cells, let's see another. For eyesight we need light, in this case sunlight. The radiation, emitted by the Sun, is a wide range of electromagnetic spectrum, which is largely absorbed by the Earth's atmosphere. Two segment reach the ground, our habitat. One of them is the ~ 103m wavelength, we call them radio waves and the other a 10-5m – 0.5*10-6m wavelength segment. The radio waves can be detected mostly by metals and because of big length wave no effect with smaller things, therefore the radio waves can not give any information about smaller bodies, objects and so on. The other segment, because of short wavelength, even small parts, as like a cell, can also effect, according to the material specific properties, based on absorption/reflection rules, thus able to give detailed information about any part if it is contacted with light.
In the early stage of life, it was only enough to detect the sunlight for subsistence, these light sensor cells are in human brain too and regulate the daily rhythm. Later it was not enough, these cells are developed further. For example, 130 millions receptors, rods, are in human eye for detecting the light and 7 millions cones (S, M, L) for color perception. The different wavelength light stimulate them in different extent. The stimulus spread in nerve up to the brain like electric impulse, where the brain order appropriate color by cones, brightness by rods and create the picture.
Thanks to the evolution we enjoy the eyesight and our all other organ, our life, the development and existence of wildlife, which were specified by the Sun and all other ground conditions, which evolved over billions of years of evolution and what we believe are fixed and "natural".