The Mystery of Who Has Wings for Flying and Who Has Fingers for Grasping


August 12, 1991|By JOHN BRAIN

The world of paleontology is abuzz with news of the discovery of fossil skeletons of a primitive bird that antedates Archaeopteryx by 75 million years. Found in the 225-million-year-old Dockum Foundation in Texas, Protoayis texensis is described as more birdlike than Archaeopteryx and suggests that birds were flying around for ages before the famous ''first bird'' was discovered in 1861, shortly after publication of Darwin's Origin of Species in 1859. It implies that Archaeopteryx was not an early bird form but really a throw-back to its reptilian ancestors.

Archaeopteryx, you recall, had the skeletal form of one of the cute little dinosaurs of its era, but also a long tail sprouting feathers which proved it a ''missing link'' between the reptiles and the birds. It was not a flying reptile, like the pterosaurs, but a modern bird with wings and feathers more or less as we know them.

Wings and feathers. The world of birds. It encompasses eagles, albatrosses, condors, owls, pigeons, woodpeckers, sparrows, cranes, geese, penguins, ostriches, as well as innumerable extinct dodos, etc. It is an evolutionary house of wonders, and it was the separate evolution of different finch species that helped guide Darwin to his theory of natural selection.

But the real wonder of the bird world is not its proliferation of species but its origin. Once flight as locomotion was established, it took only time to enable birds to soar, wade, paddle, flap and dive, puttering around on land, sea and air.

We can understand how lungfish emerged from the water on stubby fins and how birds re-entered the water again as cormorants and penguins, eventually abandoning the air entirely. But it is difficult envisaging that first missing link.

The real mystery is how birds came to fly in the first place. How could creatures used to running around on the surface of the earth begin to evolve wings that would support them and propel them through the air? Or feathers marvelously adapted to flight, which would form flexible wings as aerodynamic as modern aluminum and fiberglass?

For evolution is not teleological. Except in man, the creative animal, life forms do not evolve toward some eventual goal. They adapt to now, environment as they find it. So how did any species of reptile or whatever begin to evolve wings, when proto-wings, nubby stumps with near-fingers, won't do diddly to get you off the ground?

Flying fishes are only water-skimmers; they evolved fins to get them close to flying in and on the water, then transitioned to real flying when they skimmed fast enough. But beating your little arms won't help you fly however hard you try, and the dinosaurs knew nothing about trying. Meanwhile you may lose the use of your fingers, those divine digits that enabled man to grasp and eventually comprehend the universe.

The bone structure of wings is similar to our arms and fingers, spread out and adapted to flight. But how did bird-brained creatures make that first step from the earth to the air?

What mere arm, whether of man or Tyrannosaurus Rex, can add to one's propulsion through the air? How could scales or nails or skin begin the evolution into feathers?

Man, the designer, thinks of God as like himself, a thinker who turns ideas into plans into creatures. But according to Darwin and common sense, God didn't design creatures the way we design airplanes. His method, the way of evolving nature, produced design last, not first. It is in us that God emerges, not in some Great Architect of the Universe.

Philosophical speculation aside, the emergence of flight is a conundrum. But once our common ancestor (or at least our colleague ancestor) ''elected'' to go the way of wings rather than fingers, the die was cast. The long journey to flapping and riding the waves and thermal currents was begun, never to turn back, and the way to grasping and tool-using and writing and computing was abandoned forever.

When I look at any animal -- pets, cattle, ''wild'' animals, even insects -- I am overwhelmed by a sense of evolutionary kinship, a sense of the accidents and ''decisions'' that led to us and them.

And when I encounter an eagle while soaring over the Appalachians in my glider, both of us riding the air currents and using the very same thermalling technique to stay up and fly across country, and we exchange glances, I experience a sense of powerful kinship that goes back to Archaeopteryx and Protoayis and beyond.

Now we know so much more than the birds. Our hands gave us the edge. And with our hands and brains we have created our own wings and now soar with them. But the mystery remains, more mind-boggling for us than for them. It is like reaching out to touch the hand of the Divine.

John Brain is a free-lance writer and glider pilot in Baltimore.

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