Chickens, Eggs, Passions, Work

Do we move toward our passions in life or do those passions develop based on the way our life evolves?

Reading a description of natural phenomena that have developed over the course of 350+ million years got me started on this latest chicken and egg exploration. I began reflecting on people who choose geology as a field. Given the long view they study, I'm guessing a serious geologist might find my pre-occupation with the modern era tiresome. I'd also bet as a group they would tend to have better perspective than I given how present and future focused I can be. But even if I'm wrong on both counts, is a passion about the distant past part of what drives people toward geology? Or, does that passion develop as a person becomes enmeshed in the field? How about you and your passions? Chicken or egg?

While reading "A Widower's Tale" (Julia Glass) I was further struck as a character considers his oncologist mother. He wonders if his mother was drawn to that work because she was always adept handling worst-case scenarios. Or, did her work shape and strengthen a skill he believed was there from the start? So, why did the chicken cross the road? To lay this egg somewhere in the middle?