Harmony and Conflict in the Living World - Alexander F. Skutch [6]
Toughness and Aggressiveness of Life
A great paradox of living substance is its combination of tenacity with extreme frailty. It is so easy to destroy by heat, by intense illumination, by chemicals of a thousand kinds, by mechanical violence;
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A fundamental property of life is its stubbornness, its opposition to the forces that would carry it away, reduce it, or annihilate it. The swiftly flowing river bears downward, for yards or miles, a stick, a stone, or any other lifeless thing that may fall into it; but all its free-swimming living inhabitants, from great fish to frail beetles and striders and other organisms so small that they escape the careless eye, set their heads resolutely against the current and resist its force. The fish in the mountain torrent is symbolic of all life, in the water, on the ground, or in the air: it resists the forces that would carry it along. Life seems to be pitted against the external world; struggle is its essence. And although against cataclysmic forces it is pathetically helpless, tossed like a feather by the tempest, burnt to cinders by a puff of volcanic vapor, for all its frailty it is the toughest thing under the Sun.
To add to the paradox, this thing at once so delicate and so resistant, so ephemeral and so enduring, tends ever to clothe itself in forms that present a greater challenge to all that is inimical in its environment, as though exulting in opposition to elemental forces and delighting to devise new ways of thwarting them. To the seaweed floating in still water, the maintenance of life is relatively simple. Constantly bathed in a liquid containing all that it needs for respiration and growth, it is hardly affected by the pull of gravitation; neither scorching sunshine nor drying wind is a yet with incredible Protean cunning living things outwit destroyers and blossom forth again with renewed vigor and fertility. A rock in your field is troublesome; you carry it away and see it no more. But pull up a weed, remove it, burn it, grind it into fragments, utterly obliterate itand the chances are that within a few months, seeds or fragments of it that escaped your notice will have produced a hundred weeds where you found one. To emphasize the evanescence of human life, moralists sometimes ask where are the hands that erected the Pyramids or built the Parthenon. Where are they, indeed? Those hands are multiplied a thousandfold; they are in Europe and America and Africa and Australia and on the farthest islands of the oceans; while the stones that they set in place daily dwindle under the action of wind, rain, and frost.
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threat to it; it has no occasion to send forth roots to gather essential elements thinly diffused through the soil, then transport them to distant organs.
Why did not vegetation remain forever content with the security of the aquatic environment in which it arose? What stubborn perversity of the living substance goaded it into invading the land, into assuming forms the continued existence of which is a miracle of audacity? In every respect in which life is simple and safe for the seaweed, it is complex and perilous for the tree. Whereas the alga vegetates in a caressing bath of nutrient fluid, the tree rears its lofty head as though to defy the gales and the lightning, the drying winds and the desiccating sunlight, the unremitting gravitational pull of Earth. It is endlessly extracting water and solutes from the soil and, by a process that has been difficult to understand, raising them fifty or a hundred yards