I think I may have had an epiphany, but I can't be certain because (a) I can't spell epiphany and (b) I'm not entirely sure what one is. All I know is that whenever I look in a mirror I feel a sense of awe and wonder that is hard to put into words.
What? No! Don't be silly, I'm not talking about my legendary good looks. It would be immodest of me to do so, and I pride myself on my humility. I'm talking about something much deeper and more meaningful (as hard as this may be for you to believe).
Actually, this has been building for some time. Out of all the books I've read, and I've read a lot of books, one that truly boggled my mind and that stays with me to this day is Wetware: A Computer in Every Living Cell by Dennis Bray.
Dennis does a masterful job. He starts by describing how a single-celled creature like an amoeba functions, including how it creates proteins and how interactions between different proteins can be used to detect external stimuli, perform "computations," make "decisions," and initiate actions. For example, even though an amoeba comprises only a single cell, it can "crawl" around, hunt for food, and respond to external stimuli like lights and sounds and smells... all without muscles or a nervous system.
Next, we move to colonies of single-celled creatures that use proteins to detect each other's presence and to communicate. This leads us to simple multi-celled creatures, in which the different cells forming the organism manage to communicate with each other so as to achieve a common goal.
All of which leads us to the current pinnacle of evolution as we know it, which would be me. Well, you too, of course, but mostly me. (Hey, it's my epiphany we're talking about here!)
My head is buzzing with the amazing things we've discovered, such as how the DNA in our cells actually includes virus DNA. (Approximately 8% of the human genome is made up of retrovirus DNA in our genes.) Or the fact that the number of bacterial cells in our bodies outnumber our human cells by a factor of 10 to one. (Bacterial cells are very much smaller than human cells. The combined weight of all the bacterial cells is approximately 3 lb in an average adult human being.)
And then we have epigenetics, in which the underlying DNA doesn't change, but small chemical groups and proteins can attach themselves to the DNA and affect gene expression (i.e., which genes are active or inactive). This is one of the mechanisms behind the way in which our cells differentiate themselves into skin, muscles, nerves, etc. More recently, it's been recognized that an organism's epigenome can be modified by changes in its external environment, and that these changes can passed down to that organism's offspring, all without mutating the underlying DNA.