That’s a bit simplistic an answer. Biological evolution includes social activities of animal species. Sexual selection is a big driving force, for instance, giving such things as the peacock’s tail. The social behavior of animals is a strong influence on their evolution, so ruling out human culture as an evolutionary driver is unjustified. In fact, there’s a whole field trying to study the effects of culture and social factors on the evolution of humans, and vice versa – Evolutionary Psychology.

There actually have been attempts by people to answer that question. Richard Dawkins has written an essay on the topic, and I’ve seen some others.

Consider that Neanderthal graves have been excavated with flowers included in the graves. This has been interpreted by some scientists as suggesting Neanderthals were concerned about dying and perhaps had religion of sorts. If that is how far back the origins of religion stem, they have played a long role in the development of Homo Sapiens sapiens (i.e. modern humans).

One explanation is that when early humans/ancestors were first developing self-awareness, they began to ponder the big questions – Where do I come from? What is death? What happens after death? How does the world work? Etc. Without formal science or even a culture of thought, they made guesses based on observations. By noting that things happen because of causes, and noting that living things were good causes, especially themselves, they extrapolated the events of the world as being caused by beings. Since those events were beyond their own meager abilities, the causers must be more powerful and hidden than mere mortals. Ergo, gods, demons, spirits, elves, whatnot.

How did this influence human evolution? It has been noted the role plays in defining a societies morals and codifying acceptable behavior. Will of the gods, divine retribution, placating spirits, etc become powerful tools for establishing controls on society, encouraging social behaviors that are better for the group if perhaps not particularly advantageous to the individual. Things like sharing food or water in times of scarcity, sacrificing life and limb to defend the tribe, etc. While one can understand the genetic influence and instinct to protect one’s offspring, it is less certain about instinct to defend one’s cousin, uncle, sister’s children, etc. However, biologically it makes sense (from a gene transfer standpoint, your siblings have similar genetic makeup to you, their offspring about a 1/4 your genes, etc). Social dynamics have been shown to develop from purely social interactions independent of biological imperatives. (Game theory for the “prisoner’s dilemma”, for instance.)

However, an important part of social order is establishing the “in group”. Consider the effect of freeloaders on society – those who take the benefits of cooperation and sharing, but don’t give the sacrifices themselves. Such as taking someone else’s food when offered but hoarding one’s own, or living in protection of the group but never helping defend from predators or opponent groups. Society has a need to establish who are the real insiders, the one’s likely to cooperate and share, and who are the fakers, taking the benefits without the sacrifice. Thus the development of elaborate rituals and codified behavior, things that require commitment and can’t be easily faked. Getting your face pierced by a stick through the nose or getting tattoos and piercings are less likely to be done on whimsy, and are efforts of group cohesion. Esoteric knowledge of rituals that require practice and effort to perform build a person’s individual commitment to the group, and serve not just as easy visual cues, but also as community builders that make the person more likely to feel committed.

Religion, therefore, plays a strong role in uniting a community, not just by defining the morals and providing the justifications for following the rules and the threats of punishment/offers of rewards, but also by building social cohesion and group dedication in the membership and serving as outward signs of group membership. In this way, religion actually has an active role in the biological evolution of humanity. After all, we all are aware the dangerousnous throughout history of not complying with the local religious beliefs. At a minimum, it can get you kicked out in times of distress, if not blamed for the distress. At a maximum, it can get whole populations exterminated. Thus, believing becomes selected for by natural selection.

This is, of course, speculation, but makes a lot more sense than just dismissing the question without any consideration.

BA, how did the scientists calculate the methane distribution from that pic?

Jay – my sister’s husband happens to be from a Lebanese family. His mother, father, grandmother, sister, uncles, aunts, etc., all speak Aramaic.

Most literalists don’t have a clue where their documents come from and refuse to accept their myths are stolen from much older myths. My reference to Aramaic was sarcasm. I’m not sure Aramaic was even a written tongue, and I do know that the early Bible tales were passed down orally for centuries before being written. That’s true of every religion except, maybe, for Islam, Mormonism, and some of the more recent offshoots of the major religions, and even they claim to have ancient roots.

The big problem with monotheistic faiths is that all of them are essentially tribal religions that have been stretched to cover people and situations they were never “designed” for, creating huge holes. At some level, their proponents recognize those holes, but some deny that truth and project their own misgivings on to others, blaming them for the fact that the religion can’t possibly cover everything.

Since this is a science blog, I’d like to toss out a question: What purpose does religion serve in terms of evolution? (It’s not likely it would’ve become as widespread as it is if its effect on human survival chances was wholly negative.) What keeps it going?