Darwin, Natural Selection, Birds, Beasts and Trees

The Connectedness of all Things

I treasure these two books by Bernd Heinrich: Mind of the Raven: Investigations and Adventures with Wolf-Birds, and The Trees in My Forest.

As I now read Raven and reread Trees, I recall several others in the realm of natural science that have deeply affected me: The Song of the Dodo: Island Biogeography in an Age of Extinction, by David Quammen and The Beak of the Finch: Evolution in Real time, by Jonathan Weiner.

I recall, in addition, Where the Sea Breaks its Back: The Epic Story of Early Naturalist Georg Steller and the Russian Exploration of Alaska, by Corey Ford. This book is mostly a true adventure story. It does, however, spotlight the great naturalist Georg Steller after whom so many animal species are named: the Steller Sea Cow, the Steller Jay, the Steller Sea Lion, the Steller Sea Eagle, and so forth.

 

So, where to begin in a realm where there can be no beginning, where every thing and every event is preceded by and dependent upon some other thing and event, ad infinitum? How about this passage from Where the Sea Breaks its Back?

My wife is much too brazen… I have in her stead two young ravens… I have quite forgotten her and fallen in love with Nature…”

The 25-year-old German Georg Steller, a physician and naturalist, was on his way across eastern Russia and Siberia to the eastern edge of the Asian continent to accompany the great Danish explorer Vitus Bering on his adventure to Alaska, in service to the Empress Anna of Russia. The quotation provides a segue to the book about the raven. (More about the book and Stellar, further below).

Raven

Raven is a major figure in the mythology of many cultures: Athabaskans and other original peoples of the western North American continent, including Alaska; Germanic peoples, including ancient England and the Nordic countries; the Celts; and, there is brief mention of Raven in The Talmud and The Qur’an.

Raven (Source: Alaska Native Heritage Center, http://www.alaskanative.net/en

It seems clear, from the work and writing of Heinrich, that Raven without Wolf and, more recently, without Man-as-hunter, the species would have to have adapted other ways in order to have survived to this day. A speculation I proffer is: would Man-as-hunter have survived without Raven? Perhaps not, in that there is strong evidence that Raven shows the hunter (Wolf or Man) the location of large prey from its lofty and far-seeing position, in order to share the bounty of the successful hunt.

Other facets of ravens and their behavior are fascinating to learn about, including the possibility they have a reasoning “mind.”

Survival of the “Fit Enough”?

The phrase “survival of the fittest” is often used as a representation of what Darwin has taught us about natural selection, but it is faulty.

“Survival of the fittest” is a phrase which is commonly used in contexts other than intended by its first two proponents: British polymath philosopher Herbert Spencer (who coined the term) and Charles Darwin.

Herbert Spencer first used the phrase, after reading Charles Darwin’s On the Origin of Species, in his Principles of Biology (1864), in which he drew parallels between his own economic theories and Darwin’s biological ones, writing “This survival of the fittest, which I have here sought to express in mechanical terms, is that which Mr. Darwin has called ‘natural selection’, or the preservation of favoured races in the struggle for life.”

Darwin first used Spenser’s new phrase “survival of the fittest” as a synonym for “natural selection…” Darwin meant it is a metaphor for “better adapted for immediate, local environment“, not the common inference of “in the best physical shape”. Hence, it is not a scientific description, and is both incomplete and misleading…(Emphasis added)

Herbert Spenser, 1820-1903; Charles Darwin, 1809-1882

An interpretation of the phrase “survival of the fittest” to mean “only the fittest organisms will prevail” (a view sometimes derided as “Social Darwinism“) is not consistent with the actual theory of evolution. Any individual organism which succeeds in reproducing itself is “fit” and will contribute to survival of its species, not just the “physically fittest” ones… A more accurate characterization of evolution would be “survival of the fit enough…”[Source].

The Beak of the Finch clearly shows the benefit to a species in adapting to “immediate, local environment.” The book presents the painstaking gathering of data for over 20 years on the Galapagos Islands, documenting the current evolution of the beaks of finches to adapt to the shape of available seeds. The shapes of the seeds depend on the amount and extent of seasonal and annual rainfall, which is quite variable.

Trees, their “mutuals,” commensals and parasites

Ant mound in the forest near Saltaluokta Mountain Station, “Lappland,” Sweden, July, 2008

What I had remembered from my reading, years ago, of The Trees in My Forest was that certain trees depend on ants for survival, and vice versa. Their relationship is a “mutuality.”

Upon my recent re-reading of the book I was reminded that for all trees, everywhere, there are relationships with other organisms that are vital to one or both parties: birds, bees and many other insects and mushrooms, for instance. Some events in nature are both friend and foe: wind, fire, ice, and snow. Some insects and non-animal organisms are deadly to some trees (e.g., Dutch elm disease) but other insects and organisms will help to ward off such diseases.

The question of why some trees are deciduous is discussed. It is a matter of adapting to the ice and snow that would otherwise accumulate on their broad leaves and vulnerable branch angles. The evergreen conifers have adapted by having branch angles and leaves (needles) which slough off the otherwise branch-breaking weight of accumulated snow and ice.

Of the five books presented here, I count this as the most poetic and revealing of the nature of Nature. Life is an intricate web of relationships which can unravel, in a given locale, when a key player is eliminated through forces of Nature and through Nature’s sometimes unwitting, sometimes insensitive agent, Man.

Islands, Biodiversity and Ecosystem Decay

As David Quammen points out in The Song of the Dodo, the Galapagos Islands are not unique in hosting species found nowhere else.  Islands, disconnected from the mainland, whether originally connected (such as Tasmania) or not (such as the Galapagos), affect the local species in ways that cause them to diverge from species on the mainland.

A salient point made by Quammen is that one will find unique, but fewer species on a island or set of related islands. There is a direct relationship between the size of the habitat and the number of species supported by it.  What man has done to the mainland is to create many smaller habitats our of previous large and continuous habitats thus, in effect, creating islands where the number of species will decline and, perhaps, mutate over time into new species—if the animal or plant species will survive at all. Here are some words the author writes in the

A Galapagos Hawk about to land on a giant Galapagos Tortoise (Source: http://www.progresoverde.org/)

Introduction:

An ecosystem is a tapestry of species and relationships. Chop away a section, isolate that section, and there arises the problem of unraveling…

They have invented terms for this phenomenon of unraveling ecosystems. Relaxation to equilibrium is one, perhaps the most euphemistic. In a similar sense your body, with its complicated organization, its apparent defiance of entropy, will relax toward equilibrium in the grave. Faunal collapse is another. But that one fails to encompass the category of floral collapse, which is also at issue. Thomas E. Lovejoy, a tropical ecologist at the Smithsonian Institution, has earned the right to create his own term. Lovejoy’s is ecosystem decay.

The Otters of the Aleutian Islands

Where the Sea Breaks Its Back (published 1966) ends with a passage about the recovery of the Aleutian sea otter after the depredations of  Russian hunters, first, then others later.

The rate of increase in the two decades after the (Second World) war has been prodigious. Today there are more than five thousand otters on Amchitka alone, and they have reestablished themselves around Kiska, and down the island chain as far as Attu. The latest official count of the Fish and Game Department estimates approximately thirty thousand in Alaska. “The sea otter could again become an important part of our coastal fauna,” the California Museum of Vertebrate Zoology has stated. “The conditions for subsistence remain as about as favorable, except for the presence of the human hunter, and his activities could be regulated.”

Its food supply still exists in abundance. Its original habitat in the Aleutians is virtually the same as in Steller’s time. Perhaps for once, with proper conservation measures, we can reverse our long sad history of despoilation and plunder, and restore this shy and beautiful animal which, in the words of Alaska’s first naturalist (Steller), “deserves from us the greatest reverence.”

Unfortunately, since this book was published 44 years ago, the Aleutian sea otter population has become endangered, according to this petition to the national Fish and Wildlife Service by the Center of Biological Diversity in Berkeley, California in year 2000.

Human Ecology

The authors of the books presented here have an appreciation for the connectedness of things, living and otherwise. My first inkling of this concept was engendered by my taking a course entitled Human Ecology and Public Health, one of the courses at the School of Public Health in Berkeley in 1962, from which I ultimately received my BS and MPH degrees. The course has since been incorporated into others with different names.

The course content provided an awakening for me. I was, prior to this, a rather linear fellow (still tend that way) but now I could no longer accept a rather one-dimensional stream of cause-and-effect as a paradigm for the world and the universe.

The world of family and job responsibilities, however, tends to channel and focus one’s energies, only to cause one to lose sight of the great web of which we are a dynamic part. These books have re-oriented me to what I call “the real world” when I am hiking in the hills and mountains of California and, now, Sweden in the summertime.

Overlooking Storelulevatten (roughly “big lake Lule”) near Saltoluokta Mountain Station, in “Lappland,” Sweden, July, 2008

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