Darwin's theory of national selection was publish in 1859. Darwin would have been well aware of how humans, since the dawn of civilization, consciously bred animals and plants to enhance their desirable properties. This is called human selection.
His trip to the Galapagos brought him to a place, untouched by humans, but which showed plant and animal life, optimized to its natural environment. He called this natural selection since it was remote and untouched by humans. It was only touched by nature and selected by nature, apart from man. He formed a parallel between well documented human choices and natural choices.
He used the word natural, instead of Divine, since natural was the part of God's creation subject to science. Divine also included things that science may not be able to fully investigate. In the bible, humans were to become the caretake of the earth and to know how to do this well, we needed to know how creation works
Darwin had a medical degree and he was well aware of the science of his day. Statistical science was not new. If you look in Wikipedia, the first use of statistical math dates back to roughly 800 AD, a thousand years before Darwin's paper was published. Darwin did not choose a randomized approach, even though it was available as an option. He knew humans selected plants and animals based on the observations, that like begets like; cause and affect. You cannot blend corn and tomatoes and randomly expect wheat. That would have been called alchemy. But you could blend only short haired dogs, and get a new breed of dogs with only short hair. This was rational and based on cause and affect; age of enlightenment. DNA was not known at that time and his approach, as a doctor, was rational and not random.
Natural selection was consistent with the religious views of monotheism and an omniscience God. Natural selection ends up with the best of the best under any given set of conditions. Even if a tree falls on the initial best, what is left will still end up with its best. This approach was not consistent with polytheism, and the whims of the gods of statistics. Polytheism allows a renegade god to add a magic wild card. Darwin never claimed this. That approach was used by the alchemists to compensate for lack of understanding.
In terms of religion, monotheism sets one set of universal rules, that allows for cause and affect in nature; divine plan of intermeshed parts. Polytheism had many gods, pulling in various directions, acting in emotionally impulsive and whimsical ways, to create disorder and exceptions. This is an older way of looking at reality. Darwin's approach was more consistent with the more modern monotheism angle, which favored natural cause and effect leading to strong, robust and healthy critters, in any natural conditions. Statistics was more like whims of the gods and allows gold from lead; finite odds. Darwin never assumed a science casino parallel; polytheism, where difference are expected in each experiment based on whims du jour. That is due to bad or irrational theory.
The math of statistics is the same math used to model gambling. That says a lot. Gambling is a manmade invention, that is not natural (selection). In a deck of cards, all cards have the same objective dimensions, weight and material. They differ by the subjective facades defined by man. Nature does not work this way. Darwin was not interested in man made selection, but only natural selection. Manmade might choose a facade, such as breeding a black cat, which may not be natural selection in a snowy land. Natural tends to pick in terms of function more than form. Science can quantify function. Form, without function, is subjective and is not quantifiable except via self serving politics.
If you look at a deck of cards, each card is quantitatively the same, in dimensions and materials, but has a subjectively different value, with the top cards Jack, Queen and King. The Ace can be higher than the King or lower than the deuce. The Ace symbolized God. He could lead King in the minds of the faithful, or be worthless in the minds of Atheists.
If you look closely at this manmade game, defined by the laws of statistics, it was a metaphor for the classic social hierarchy since the beginning of culture. One's position in culture was defined by man based on subjective criteria; facade. The King was the top dog of secular society. This was not based on any quantifiable science parameter such as strength, fastest runner, best intellect, etc. We did not measure everyone, by objective standards, and let natural selection choose; God's plan. This was fixed in advance, by man, with no objective tests used. The free market changed that.
The King of cards was an inherited position all based on subjective convention. Based on that convention he was always the best, without the need to be tested, objectivity. Racism uses the same card schema where social position is decided by a facade of skin color, which then defines which card you are in the deck. In the old days, one may not be able to move from that card value. Your children if born into a three will aways be lower than the four, but higher than the two.
The reverse discrimination being employed by the left, simply redefines the faces of the playing cards, but it does to change the game. It is all politics and facade not supported by any objective measures, like standard test scores. This is polytheism modeled, with statistics, to hide the needs for objectivity and science based decisions. Darwin did not go there, but he nevertheless had to walk a tightrope because of political subjectivity, that benefited by the deck of cards approach. This had even infiltrated the Church. Both benefited by whims of the gods and odds, but not by objectivity.
Those of faith, do not throw Darwin out with the bathwater, since his approach was consistent with a planned universe of cause and affect. The politics you now see, that misrepresents Darwin, is based on the polytheism of statistical models and gambling, trying to define its approach as the King and the Ace as the one. If you accept that, then the game can be played better with whims of fake news and statistics.
In rational sciences, theories need to hit the bull's eye. Recently they sent a Mars rover to Mars without any human control to fine tune the descent. This mission was based on objective science, since it hit the bulls eye with the theory, after shot left the earth. Statistical theory only has to hit the target even off the playing grid. That is called statistically significant. This is a very watered down standard. Darwin envisioned the bulls eye and not just hitting the target support stand via polytheism and whims of the gods.