pattern to it; and there can therefore be no prescription, and nothing resembling destiny.
Tree ferns once abounded. Some, like this
Dicksonia,
are still with us.
Hard-nosed biology is at present more fashionable than theology, so notions of random walk now prevail over those of destiny. But fashion is a poor guide to truth. One stunning and undeniable fact of evolution is the phenomenon of convergence: the way in which lineage after lineage of creatures have independently reinvented the same body forms and, often, the same kind of behavior. There may be no literal prescription for how life should turn out—but any two creatures in the same kind of environment tend to evolve along much the same lines. Sharks, bony fishes, ichthyosaurs, and whales all independently reinvented the general form of the fish (and so, for good measure, did penguins and seals). Water poses its own particular problems, to which there is one optimal solution, which they all adopt. Among plants, lineage after lineage has independently reinvented the form of the tree. A tree, after all, is a good thing to be.
So nature may not be literally prescriptive. But it is not random either. Living creatures are in perpetual dialogue with all that surrounds them—with the other creatures they encounter minute by minute, and with climate and landscape, which means they are in perpetual dialogue with the whole world, which in turn is subject to the influence of the whole universe. Whatever other creatures may do, however the world changes, each individual must take everything else into account. Each of us is engaged in this dialogue with other creatures and with the universe at large from conception to the grave. Furthermore, what applies to individuals also applies to whole lineages of creatures, as they evolve over time: all lineages of living creatures, whether of oaks or dogs or human beings, are engaged in this dialogue from inception to extinction. All creatures might in principle be able to evolve in an infinite number of ways as Darwin suggested, but if they are to survive along the way then each must solve the particular problems of its own environment at all times—and to each problem there is a limited number of solutions. There is something about the universe, at least as it is manifest on earth, that seemed to demand the emergence of fish and of trees (and perhaps—who knows?—of human intelligence). The physicist David Bohm spoke of the “implicate order” of the universe. Fish, like trees (and human intelligence) reflect this innate, implicit orderliness. They are its manifestation.
What follows is an outline of what’s known about the historical (evolutionary) events that led to modern trees. I will discuss it as a series of what I will call “transformations.”
TRANSFORMATION 1: LIFE
The first transformation on the path to treedom was the evolution of life on earth—probably more than 3.5 billion years ago (the earth itself seems to have begun about 4.5 billion years ago). So how did life begin?
In modern body cells, whether in people or in trees, the genes, in the form of DNA, sit in the middle, ensconced within the nucleus, like the chief executive in his office. They give out orders, which are relayed by RNA (a smaller molecule akin to DNA) to the rest of the cell outside the nucleus (the cytoplasm), where these orders are carried out. Accordingly, DNA and RNA are often taken as the starting point of life itself—as if there is not, and never could have been, anything that could lay claim to life before DNA and RNA came on the scene.
Look closer, however, and we see that the flow of information within the cell is two-way: the genes themselves (the DNA) are turned on and off by signals from the cytoplasm, which in turn relays messages from the world at large. In short, DNA is in dialogue with cytoplasm, with all its intricate chemistry. Even at its most fundamental level, life is innately dialectic.
It follows from all this
Tree ferns once abounded. Some, like this
Dicksonia,
are still with us.
Hard-nosed biology is at present more fashionable than theology, so notions of random walk now prevail over those of destiny. But fashion is a poor guide to truth. One stunning and undeniable fact of evolution is the phenomenon of convergence: the way in which lineage after lineage of creatures have independently reinvented the same body forms and, often, the same kind of behavior. There may be no literal prescription for how life should turn out—but any two creatures in the same kind of environment tend to evolve along much the same lines. Sharks, bony fishes, ichthyosaurs, and whales all independently reinvented the general form of the fish (and so, for good measure, did penguins and seals). Water poses its own particular problems, to which there is one optimal solution, which they all adopt. Among plants, lineage after lineage has independently reinvented the form of the tree. A tree, after all, is a good thing to be.
So nature may not be literally prescriptive. But it is not random either. Living creatures are in perpetual dialogue with all that surrounds them—with the other creatures they encounter minute by minute, and with climate and landscape, which means they are in perpetual dialogue with the whole world, which in turn is subject to the influence of the whole universe. Whatever other creatures may do, however the world changes, each individual must take everything else into account. Each of us is engaged in this dialogue with other creatures and with the universe at large from conception to the grave. Furthermore, what applies to individuals also applies to whole lineages of creatures, as they evolve over time: all lineages of living creatures, whether of oaks or dogs or human beings, are engaged in this dialogue from inception to extinction. All creatures might in principle be able to evolve in an infinite number of ways as Darwin suggested, but if they are to survive along the way then each must solve the particular problems of its own environment at all times—and to each problem there is a limited number of solutions. There is something about the universe, at least as it is manifest on earth, that seemed to demand the emergence of fish and of trees (and perhaps—who knows?—of human intelligence). The physicist David Bohm spoke of the “implicate order” of the universe. Fish, like trees (and human intelligence) reflect this innate, implicit orderliness. They are its manifestation.
What follows is an outline of what’s known about the historical (evolutionary) events that led to modern trees. I will discuss it as a series of what I will call “transformations.”
TRANSFORMATION 1: LIFE
The first transformation on the path to treedom was the evolution of life on earth—probably more than 3.5 billion years ago (the earth itself seems to have begun about 4.5 billion years ago). So how did life begin?
In modern body cells, whether in people or in trees, the genes, in the form of DNA, sit in the middle, ensconced within the nucleus, like the chief executive in his office. They give out orders, which are relayed by RNA (a smaller molecule akin to DNA) to the rest of the cell outside the nucleus (the cytoplasm), where these orders are carried out. Accordingly, DNA and RNA are often taken as the starting point of life itself—as if there is not, and never could have been, anything that could lay claim to life before DNA and RNA came on the scene.
Look closer, however, and we see that the flow of information within the cell is two-way: the genes themselves (the DNA) are turned on and off by signals from the cytoplasm, which in turn relays messages from the world at large. In short, DNA is in dialogue with cytoplasm, with all its intricate chemistry. Even at its most fundamental level, life is innately dialectic.
It follows from all this
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