Essentials

Evolutionary biologists who strip life to its essentials have suggested that humans are basically just DNA replication machines.

Purpose of life? To pass on our DNA code of nucleotides, in combination with a partner’s, to succeeding generations. All the work, love, ambition and angst is, in the end, a lot of sound and fury about maximizing the chances of successful replication of our genetic code. Brains, money, opposable thumbs, poetry: it’s just DNA strategy.

This doesn’t fit our intellectual and spiritual convictions about our own self-importance. To suggest the purpose of life is to perpetuate a string of amino acids is a little deflating.

But it’s simpler.

The cycle is clearer in animals. For all their glory, butterflies emerge, feed, mate, lay eggs, hatch as caterpillars, pupate, and emerge…to make more butterflies.

And yes, there is homosexuality in both the human and animal realms, but they share the sexual imperative that drives reproduction.

This biological musing came up recently when watching my one-year-old grandson Isaac, and while visiting an old growth forest with a noted ecologist.

Isaac has a lot going on. He can’t walk yet but works constantly on moving, boosting higher, and manipulating toys with his fingers. He is intrigued when he spots his own reflection. He is fascinated with books that have baby pictures. He is also a student of adult psychology, watching we grownups so he can find ways to get us to do what he wants.

He asserts independence by turning his cheek to offered food or shoving it dubiously around on his highchair tray. Critical appraisal established, he’ll then happily eat what he disdained a minute before.

He’ll watch orbiting hummingbirds, listen to new sounds, and announce his boredom. And someday, probably, have grandchildren of his own.

The 250-year-old evergreen forest of fir and hemlock was in Washington’s Rockport State Park, where Dr. Jerry Franklin – who I described in my book, The Final Forest – joined me to talk about its ecology and life cycle.

Franklin, I told a crowd of attendees, is a historically significant scientist who changed our view of the forest by identifying the importance of dead trees as well as live ones. Until Franklin and his fellow ecologists did their pioneering work in the 1970s, the U.S. Forest Service intended to liquidate all virgin forests in the Northwest and replace them with lively green tree farms of young, monocultural trees.

Jerry recognized that all the “dead” stuff – the tangle of logs he crawled across, and the snags that leaned precariously – was a vital part of a cyclic whole. Insects, birds, and mammals used the “woody debris” for homes and food, and new trees grew from the rot of the old.

He led us on a fascinating trail talk to explain how the thickest canopy moves up and down over time, as trees mature, in a pattern of ever-increasing complexity that stores more carbon than it releases.

Interesting fact: a Northwest standing snag will decay faster than a log on the wet ground. Reason: the log gets so soaked that the water chokes off available oxygen for bacteria, slowing the woody breakdown. The logs actually decay more in the dry summer than wet winter.

The microbes make hay when the sun shines.

Bottom line: the purpose of life – and death – is life.

Hakuna matata, as the Lion King would say. It’s a reassuring kind of immortality, as trees soar and Isaac crawls industrially after that rolling ball.

Tagged as: DNA, forest ecology, purpose of life, reproduction