While I was gardening

The art of gardening and the science of life.

Evolution of a Garden (apologies to Stephen Jay Gould)

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The first plant I added to the first garden I tended was the common Primrose, Primula vulgaris.  A cheerful little white flower with yellow throat, basal, evergreen leaves, and compact size.  Not long after planting our first Primrose I added more – this time in blues and pinks.  This garden was at a house my spouse, my brother, and I rented in a neighborhood near the University of Washington; aka the land of student housing.  As you can imagine, the Primroses offered a different take on the usual type of student “landscaping” – empty beer bottles, discarded furniture, and bicycles.  The plants didn’t survive into the following year, most likely more my fault than theirs.  But just the thought of coming home to a sight other than a brown lawn with yellow-green patches helped germinate the idea of gardening in me; an idea that, in all honesty, had been with me since childhood.

Years later, after my spouse and I bought the house we now live in, the need to garden became permanently rooted in me.  And, yes, one of the first plants I added to our landscape was Primula vulgaris.  Over the years I noticed that these plants were living longer than just a couple of seasons, with some living 10 or more years.  I doubt that this indicated an improvement in my gardening skills.  Even though the plant is hardy to zone 5, a few of our winters had brought prolonged temperatures well below freezing, without snow for protection – long enough and cold enough to kill many other zone 5 perennials.  But these little Primroses not only survived but continued to bloom and produce leaf growth into early spring, with sporadic blooms throughout the year.  Hardiness and longevity may be common for this plant, but my mother said her Primroses always died during winter.   I wondered if my success was indicative of the plant adapting to its environment over time, or evidence of our warming climate . . . or that I am a better gardener than was my mother.

Two years ago my Ribes rubrum, Gloire des Sabions, suffered from an insect infestation so severe that 90% of the leaves were eaten to the midrib.  As I don’t use insecticides, I relied on help from hard sprays of water and squishing the bugs by (gloved) hand to control the infestation.  The bugs were not aphids so I assumed that I would eventually need to compromise my principles and apply a spray to control them (it’s never good to be too principled).  Last spring brought the same infestation but because the plant showed much less damage, I decided not to apply an insecticide.  A ‘Johnson’s Blue’ Geranium, planted near the Ribes, was being attacked but not to the extent that the Ribes had been.  In May of this year, neither the Ribes nor ‘Johnson’s Blue’ Geranium had insect damage, although the insects were infecting a plant in my neighbor’s garden.  Is this indicative of both plants having adapted in just 2 years to become unpalatable to the insect?  I know I didn’t squish all the bugs.

Recent studies have shown that many plants respond to insect infestation or disease by sending out a chemical distress message through the soil to surrounding plants.  Those plants near the infected plant respond by activating genes that will fight the pest or disease if they become infected.  Could this be occurring in my garden?

Other studies have shown that Pseudotsuga menziesii, Douglas Fir, shares nutrients with its seedlings through root network systems, and that the seedlings in most need receive a greater share of those nutrients.

In my years of reading and researching science, specifically evolution and physics, I find that the underlying factor given in explanations of natural processes is of randomness.  Species evolve via the random mutations of genes, a mutation which may or may not be beneficial to the organism.  If beneficial, the mutation is passed on to subsequent generations.  If not beneficial, the mutation dies with the individual.  We are taught that nothing in the organism initiated the mutation; no message intuited by the genes that the organism could better fit in its environment if a small change were to occur.  The process is random, sometimes influenced by radiation or chemicals in the environment, but not by the organism itself in response to the environment.  I do not believe organisms purposely initiate mutation, but it seems that since there is no aspect of biological life that exists independent of its environment, somehow this interdependence should have some influence on the organism other than meeting the immediate needs of nourishment, shelter, reproduction, etc.  To me, this goes beyond natural selection.

We all are familiar with the relationship between Angraecum sesquipedale, Darwin’s Orchid, and Morgan’s Sphinx Moth, Xanthopan morganii.  This moth only pollinates Darwin’s Orchid, which grows only in Madagascar.  If the orchid goes extinct, so goes the moth.  Two immediate questions come to mind: what did the moth survive on before the orchid evolved such a long throat?  And what pollinated the orchid before the moth came along?   This is a perfect example of co-evolution; one species responding to a change in another species.  So, even though genetic mutations are random, natural selection is the process by which these changes happen.  As I have learned from reading the works of Stephen Jay Gould and Kenneth Miller, natural selection is, also, partially influenced by the environment in which the organism resides.  But is that all?

This still leaves an unanswered question in my mind: what is the catalyst that causes a plant, insect, or animal to respond to its environment?  Is it all just chemical, as many biologists and other scientists will have us believe?  This question reminds me of a book I read recently, Design in Nature, by Adrian Bejan.  He is a mechanical engineer who explains the similarity of patterns in nature as the product of flow of energy.   Dr. Bejan calls this flow the Constructal Law, which he describes as governing evolution in biology, physics, and aspects of human society.  He states, “The constructal law is a shout from the rooftops: Everything that flows and moves generates designs that evolve to survive (to live).  This is not a desire or objective but the natural tendency, that is, the physics phenomenon.”  He explains further that there is nothing intentional driving this process, “Instead, just as other impersonal, naturally arising phenomena such as gravity, the freezing points of fluids, and thermodynamics make things operate in a certain way, flow systems generate better and better flow designs.”  Well.  There we have it.  End of story.

But I don’t believe that this is all of the story.  The mysterious process of evolution, the driving force behind life, must itself be driven by something we have not yet discovered.  I will continue to read, study, and observe my garden in hopes of someday finding a deeper understanding of what makes my plants do what they do, regardless of my attention.

In the meantime, I take it on faith that the natural world will continue to evolve in the miraculous ways it always has.

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Author: dphare2014

Horticulturist, Lead Steward Carkeek Park Demonstration Gardens, Author

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