It is my opinion, that religion is a byproduct of evolution, that when a species becomes sufficiently intelligent the creation of religion is a logical and necessary step.
First we need to take a look at evolution itself. Evolution is the change of hereditary traits, within the populace of a species, from generation to generation. These traits are a result of our genetic coding. Through mutation these traits are effected. New traits can emerge, old ones disappear, or existing ones change. These mutations are then “judged” by natural selection in terms of reproductive viability. Meaning that disadvantageous mutations don’t pass their genes on as much. Due to this process traits can become more and less frequent. Advantageous traits are such, that increase the likelihood of survival and therefore the chance of reproduction. Note that evolution can also happen because of genetic drift. But its not strictly relevant to this argument.
Now imagine some earth class planet. Its pretty similar to ours. An abundance of water, mild climate, prime conditions for life. On one of the continents lives a little cave dwelling creature. Its not a complex being. It’s not self aware, has a tiny brain and a rudimentary nervous system. But its well adapted to its environment. It has limbs to climb and reach places that are otherwise unattainable. Big eyes, that process the little visual information there is and reproduces like crazy when properly fed. Its hearing is well developed, since it lives in the dark. It employs a social pattern that resembles a flock. Its one happy little critter. But then catastrophe hits. Tremors shake the ground and the continent is split in two. While one part of the continent retains its relative position, the other is sent adrift. This also divides the populace of our cave dweller. One will remain in the environment it has adapted to, the other will face profound challenges.
Over the course of a couple thousand years the newly created continent drifts farther and farther away. Due to this it undergoes a climate change. It gets gradually colder and the availability of food sources diminishes. Our creature is forced to leave the caves. Many fall pray to the new environment, but some survive. Enough to keep the species going. Over time it has increased in median body mass to outgrow the smaller predators, has improved its ability to climb by gradually developing the ability to grab and its brain has gotten bigger. It is now able to spot patterns. Not complex ones of course, but simple ones. It realizes that a ruffling of leaves and grass or the breaking of twigs indicates danger.
Skip ahead a long time again. Pattern recognition has become linked with emotional responses. When an indicator for danger is given, adrenalin is produced. Our creature is afraid, a very effective defense mechanism. And it has gained the ability to communicate these emotions. It has not developed speech but it can produce different sounds that other members of its species interpret. The social structure has become more complex. There is a hierarchy and social obligations begin to enter the picture. Through social interaction our creature has gained the ability to distinguish individual members of its species. By now its genes have changed to such extend that it could no longer reproduce with its “cousins” on the other continent. It has become a new species.
Make a time-jump again. The social structure has ultimately led our creature to become self aware. It can now, on a conscious level, determine if it is angry, afraid, satisfied and so on. It can recognize itself in a reflection. By now it has become so big, that it is only threatened by the biggest and most dangerous predators. Mental capacity is increasing continuously and with it comes an ability to recognize more complex patterns. This ability has also led the creature to sometimes spot patterns that are not actually there. This is because its pattern spotting ability has proven such a vital tool for survival, that it tries to find patterns everywhere. It is more prudent for its survival to spot a pattern where none exists, then failing to spot a pattern where one exists. That’s called a false positive. The positive aspects of the ability (by far) outweigh some falsely spotted patterns. It is through this ability and self awareness that the creature becomes capable of superstitious behavior. It will sometimes connect some action it has taken to an outside effect, it didn’t cause. Superstitious behavior is even present in the common pigeon. The creatures ability to utter sounds has increased as well, though still a long way from speech by our standards. It has begun to walk in a fashion that allow it to use tools and weapons. Begun to bend its surroundings to its will. And while it has not learned to create fire it has recognized how fire can be controlled and kept alive. Providing heat, protection and the availability of food that can only be consumed when cooked. It has also learned to understand how other members of its species feel and why they perform certain actions. As a result the social structure is becoming more complex. Climbing higher in hierarchy is very advantageous in terms of reproduction. It follows that traits allowing for such behavior are also favored by natural selection.
Skip ahead again. Teamwork is incorporated into hunting. Our creature is now able to take down even the biggest of animals. Providing it with plenty of food and other resources, for example fur and bones. It also starts to attribute person like qualities to objects of great interest like fire. Failing to understand the combustion process but still recognizing how fire needs to be “fed”. This is another false positive. It is more advantageous, in evolutionary terms, to recognize something as person like, then failing to recognize a person like entity. Speech begins to develop. Terms for food, water, weapons, fire and other common objects emerge. Eventually concepts will be described, like hunt or cook. Our creatures start to try and please objects they have attributed person like qualities to. They are now capable of worship and will (at some point) start to perform rituals based in superstitious behavior. These will be taught to their children, their childrens children.
The foundation for religion is born. When mental capacity increases further, the idea of an invisible person like entity that controls unexplained phenomena, like wind or the weather, takes form. God is created. Eventually a full fledged religion will assert itself.
If we assume that both the pattern seeking quality and the ability to understand someone else as a person are ingredients in the evolution of intelligent life as we know it today. it follows that religion is a necessary byproduct.
Today we are no longer dependent on false positives as a survival factor. We have the ability to understand and test the world around us. Determine why things are the way they are without resorting to an invisible person like entity. Overcoming religion is the next big step in the evolution of the human species.