As I've mentioned in the past, I feed the neighborhood crows, and for me, this represents an important spiritual practice.
Over time, I've noticed a trend. My crows hate when the neighborhood squirrels start taking peanuts. The crows will sometimes get stuck in a loop where they can't even eat the peanuts because they're too busy scaring off squirrels. Actually collecting the peanuts becomes less important than the abstraction of preventing someone else from getting some of the peanuts.
This morning, only one crow came by for a Christmas Eve breakfast, and that crow was quickly outnumbered seven-to-one by squirrels. She could keep any two squirrels away from the peanuts, but while she was scaring them off, the other five could run in, grab a peanut, and run away. This would make the crow turn to chase the squirrels behind her off…and the squirrels who she had just chased off could run in and grab peanuts while she was distracted.
Now, all of this behavior was clearly motivated by highly individual "selfish" impulses. I've seen the neighborhood squirrels turn violent toward each other over these same peanuts. I know that they're really just grabbing peanuts as fast as they can for their own individual use, but it doesn't escape me that these behaviors motivated by selfishness nonetheless are a primitive framework for collective action, possibly even a behavioral "seed crystal" for altruism.
I have a suspicion that, over an evolutionary timescale, a similar set of behaviors could have been transformed by the crucible of natural selection into collectivism and altruism. It's very possible that our distant ancestors were once selfishly grabbing at food in the face of a much larger creature, traits that would grow over each successive generation until helping others became so ingrained in us that we developed a sense of empathy to help enforce this positive behavior.
This is what I mean when I say that Nature is the basis for my personal religion. When you pay attention to the life around you, sometimes it rewards you with lessons better than any of those from a devotional book. My religion is not one that requires gods, supernatural forces, or miracles; it is simply a religion of paying attention to the universe in a quest to learn more about both the laws that govern it and the poetry that echoes in the application of those laws over a series of moments from the beginning of time iself on into infinity.