Trees of Life

What's the difference between a pile of wet dirt steaming in the sun, and a tree?

I've asked people this question before and have gotten that is-he-off-his-meds look from them. But it's simple enough: a tree and a pile of wet dirt are composed of the same stuff. The difference is that the tree is alive, has life, is a life. That means it takes the moisture and dirt and air and sunlight and transforms it through self-sustained processes into a structure, a form. In effect, the life of the tree takes the raw materials - literally earth, water, air and fire - and uses them to assemble a form to realize or manifest itself.

The form it takes is a branching fractal, and in fact a tree is the paradigm for all such geometric shapes; for example, a chart that shows the branching of lines of descent from an ancestor is known as a family "tree."

Which brings me to the next question that tends to elicit "that look" from people: Where does life come from?

I hasten to add that I'm not asking about the origin or ultimate source of all life; rather, simply this: If we look at a specific living thing, where did its life come from? And the simple answer is: from another living thing. Life comes from life.

What a family tree shows, from this point of view, is the history of transmission of life through successive generations, as it branches, re-branches and multiplies.

Trying to trace these lines of transmission, as I indicated in my last post, can get to be a pretty complex task. And it gets even more complex if you consider that your personal family tree is just one of billions of sub-branches of the overall human family tree, which in turn is just a sub-branch of the mammalian family tree, which again is a sub-branch of a yet-larger "tree of life."

Here's one attempt to represent this situation graphically (click to enlarge; right-click to open in a new browser window):


(Source: Wikipedia)


Drastically simplified as this picture is, it does get the basic idea across, with special emphasis on the tree-like nature of the relationships.

This next one is much more scientifically up-to-date and gives a better picture of how complicated these life-connections have become over time:

(Source: Cold Spring Harbor Laboratory Press)

Even this diagram, however, exhibits a tree-like branching structure that fans out from a single point of origin. Now, there's obviously a lot of room for debate about the exact nature of that point of origin - was it an act of divine creation, or a chance combination of organic chemicals, or the arrival on earth of some existing simple organism from the far reaches of space? - but we can safely ignore that question for now. The point is that all subsequent life consists of an uninterrupted transmission from that one original source.

Here's one more example of a tree-like branching fractal structure:



(Source: U.S. Geological Survey; photo of Selenga River delta on the southeast shore of Lake Baikal, Russia.)

What does this river delta have in common with a tree, apart from a branching structure? I would argue that both can be thought of as objects created by a type of outflow. That's obvious in the case of the river, but perhaps not so obvious with regard to a tree. But I think it's a true way of looking at a tree's growth: The life within the tree is creating a flow up into the sky by assembling its outstretching branching structure, just as the gravitational energy of the river causes it to flow into the sea, depositing a similar structure as it does so.

In the very same way, the tree-of-life diagrams above chart the outflow over the eons of life itself. What we see in these diagrams, in other words, is the history of the flow of a single stream with many branches, just like the one in the satellite photo.

In short, all life on earth is one life flowing from a single wellspring through myriad branches. From that perspective, each individual living thing is related to every other living thing in the same way as the separate leaves on a gigantic tree, or as the fingers of one individual human's hands: distinguishable as objects of a kind in themselves, but impossible and meaningless without their connection to a larger life.

I suggested last time that when we stand in line at the grocery store, there's a fair chance that the cashier or some of the other customers may be our cousins. But clearly, our relatedness is ultimately much closer, much more intimate: There is only one life, a single self-same life, in all of us. It enlivens each of us for a time as it flows through us from its unknown past toward its unguessable future.

Knowing that, how can I possibly regard you or any other living being with ill-will?