I was confused about the term natural history for a long time. What exactly is historical about natural history? It always seemed more like natural current events to me. My concept of natural history centered mostly on identifying and describing species and their behaviors. Eventually my view grew to include geology, climate, and astronomy, but it was still all just a careful description of the world we experience.
But how did this world come to be? That is the simple question that unlocked the full, grand scope of natural history for me. The world is the product of the past, and that past has been at times very different from the world we know today. I began to understand that the reality we experience is due to the accumulated changes that have happened over billions of years. The story of that past is etched into the world. The past is layered in the rocks. Every landscape is a library, and every organism is a living artifact.
In his essay, A Marshland Elegy, Aldo Leopold captures this sense of history beautifully when describing marshes of Wisconsin and the Sandhill Cranes* that visit them. He did this by drawing on the study of geology and ecology, and his lifetime of observation and contemplation.
A sense of time lies thick and heavy on such a place. Yearly since the ice age it has awakened each spring to the clangor of cranes. The peat layers that comprise the bog are laid down in the basin of an ancient lake. The cranes stand, as it were, upon the sodden pages of their own history. These peats are the compressed remains of the mosses that clogged the pools, of the tamaracks that spread over the moss, of the cranes the bugled over the tamaracks since the retreat of the ice sheet. An endless caravan of generations has built of its own bones this bridge into the future, this habitat where the oncoming host again may live and breed and die.
So, natural history is our attempt to understand the history of the natural world and how those processes that shaped the world are still operating today. I find this an endlessly fascinating way to approach the world, and I’d like to talk about a few concepts shared by all historical inquiries. I call them the three C’s: Contingency, Constraint, and Continuity.
Contingency is the idea that at any moment there are countless potential outcomes, but that only one can actually happen. We live in one of many possible worlds, and our current world is the result of a complex mixture of near certainties, random events, and infinitesimally long odds ready to send the trajectory of history off in some direction or another. In his book Wonderful Life, about the Cambrian fossils of the Burgess Shale, Stephen Jay Gould writes about contingency and the history of life. He imagines what he terms “replaying life’s tape.” If we reset the Earth to the conditions present 500 million years ago at the time that the Burgess Shale creatures were entombed, and watch history happen again, how different would that world look from ours? What do you think?
Constraint indicates that there are limits within any system that limit the possible futures that may occur as time progresses. Some of these are hard constraints like physical laws and constants, such as thermodynamics or gravity. Other constraints are conditional. For plants and animals, conditional constraints can be the genetic diversity in a population that is available for natural selection, the amount of sunlight and water received by plot of land, or the presence of a nearby predator. New events can create new constraints and new opportunities that didn’t exist before.
Continuity is the thread of history that connects the past to the present, with complex feedbacks to contingency and constraint. Continuity weaves within the bounds of constraint and follows one path or another due to contingent events.
So, why does natural history matter? Well, for one thing it is just damn interesting and it provides deeper perspective from which to view the world and our place in it. I really enjoyed Anna’s description of the winter-run Coho salmon last week, and it got me to thinking about some of the contingencies and constraints that resulted in such a wonderful population of fish. Just think about it: An oceanic plate crashed into North America, subducted , and this resulted a beautiful volcano. The geology of this volcano produces cold water springs that provide spawning habitat at a time of the year when every other waterway is too warm. This lead to a population of fish with a unique life history that is now threatened by changes made to the landscape by a recently arrived species of ape. Amazing stuff!
Every landscape is the product of a complex history. We can learn a lot about that history from the natural historical record based on geology, fossils, the geographic distribution of species, and many other types of evidence. Time is deep and full. The past is mysterious and strange, but not entirely unknowable. The land and life are forever changing, and so much of this understanding is new to us. To quote Leopold again, “We know now what was unknown to the previous caravan of generations: that men are only fellow-voyagers in the odyssey of evolution.” What a privilege!
On a more practical note, natural history helps us understand how the world works. Like all history, we study the past to better understand how our actions, given current conditions (i.e. constraints), will influence future outcomes. Being able to make better predictions has many obvious benefits. We can view natural resource management as a processes of modifying constraints and managing contingencies. Being good natural historians gives us insight into how to do this so we can influence the path of continuity to the future. We should use the bones of the past to build the bridge to the future that we desire.
*The Lodi Crane festival was this past weekend, Nov 6-8, 2015.
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