Nature’s Time Machine

"Let's set the Way-Back Machine to the year...."  Many a person in the U.S. of my generation, upon hearing that line, will recall the Peabody cartoons that were part of the Bullwinkle TV show. With that periodic segment, the Bullwinkle show joined the long line of plot-writers (primarily science-fiction) who employed the device of time travel.  It's a literary tradition that can be traced all the way back to H. G. Wells's 1895 appropriately titled novel The Time Machine.

When we look at species of plants and animals, if we have some knowledge of evolutionary biology, we can also be taken back in time.  We Homo sapiens are late arrivers on this planet (150,00 yrs. ago).  And so, knowing other species sets the dial of the time machine farther back.  To use another metaphor, if evolution is thought of as a huge tree of life with numerous levels of branches, as we look at branches that began lower on the tree, we are taken further back in time.

leaf of
a ginkgo biloba tree

Despite many extinctions, most species still around today have endured an incredibly long time.  I remember the day I noticed the unusually shaped leaves of a tree beside the sidewalk in a southern city I was visiting.  The person I was with explained that it was a ginkgo, which, unlike other trees in the U.S., was of a type that dated back a quarter-billion years.  Another example of going way back are some species of marsupials, such as ancient opossum species.  Marsupials (which include kangaroos) represent an early state of mammalian evolution, having no placenta. They bear young that are extremely small, and carry the young in a pouch for the remainder of their early development.

A nautilus,
another ancient species

For those of us who think of God as the Giver of Life and as the Fountain out of which all possibilities come, evolution can be seen as the way by which the Divine manifests its power and wonder.  Although evolution, seemingly paradoxically, requires elements of chance (such as mutations and chance experiences), there is in evolution a discernible direction toward a richer diversity of life.

Although Peabody and Star Trek episodes took the audience back in time (to such periods as Prohibition or ancient Rome), H. G. Wells's The Time Machine actually took the reader forward in time.  That is a harder task when it comes to evolution. No one studying the varieties of species 100 million years ago could have predicted that a meteor would hit the earth off the Yucatan, bringing such thick clouds that plants would die, thus cornering all the great species of dinosaurs into extinction.

We do know however, that we are suffering a loss of biodiversity -- a reduction of the number of branch-tips at evolution's treetop of the present.  The main cause is human:  the stresses of loss of habitats and climate change.  It is not yet determined in what way this plot will turn out.  Whenever we work to preserve the rich diversity of inter-species relationships that strengthen life, we try to write a happy ending for the story of life.

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Does it add something to your perspective or your life to imagine way back in time?

(The photograph of the leaf is by Daniel Miłaczewski.  That of the nautilus is by Lee R Berger.

Both are used under Creative Commons Attribution-Share Alike 3.0 Unported licenses.)