I had the privilege yesterday of getting up close and personal with various raptors at the Hawk Conservancy Trust in Hampshire. I got to meet various species of owls, a young secretary bird and some vultures, and actually to fly one of the African vultures and some Harris’ Hawks. These are in deed very special creatures.
Watching the birds at work alone shows what incredibly well-adapted and efficient animals they are. Finding out some of the facts about them only increases the admiration. Vultures, for example, are able to digest harmlessly all kinds of pathogenic bacteria and bacterial toxins in carrion, not only enabling them to survive but to perform the vital ecological task of cleaning up the environment for everybody else.
Owls hunt by night vision and hyperacute hearing and fly absolutely silently. That’s why they are useless to falconers, because we can’t help them to hunt – our presence just scares off their prey. They do better alone, though their brain is smaller than their eyeball.
I was shown one kind of hawk whose heel joint is reversible because it is an egg stealer. Or it is an egg stealer because its heel joint is reversible? It isn’t telling us which way round that goes, but it’s a clever trick for a specialist to have.
And the falcons have acquired the ability to soar to 1000 feet on thermals, spot prey on the wing at over a mile away and catch it in the air at wind speeds of well over 100mph; all (apparently) developed within the last 10 million years.
As our trainer said, these birds are so energy efficient they never fly for pleasure. Yet they are such effective hunters that much of their time is actually spent at repose. Their “constant struggle for survival” consists largely of watching the scenery. Nice work if you can get it.
But here’s the contrast. Back home, reviewing mainstream evolutionary theory, I learn that these perfectly adapted birds arrived by the accumulation of near-neutral random mutations in small populations, which swamped the mechanism of natural selection except as a purifying element, until an even smaller population got isolated in a new environmental niche, and selection built a peregrine or a bald eagle from the clutter lying around in the genome. Furthermore, though the organism is so conscious of energy saving, most of the cost of every cell division is spent on transcribing useless, or deleterious, junk. This stuff, the fruit of ancient virus infection, reproduces simply because it can, adding to the general air of jerry-building and muddle in the whole evolutionary process. Bloatware isn’t the word – DNA is apparently Blotware of nightmarish proportions.
Consider all that whilst one is actually experiencing a hawk working, and it doesn’t add up. Even Rudyard Kipling couldn’t have sold it. Strangely enough our trainer, the guy who spends all day, every day, with raptors, seemed to think something similar. He’d picked up that I was a retired doctor, so I ventured some casual remark about how amazing it was that evolution could produce such a degree of perfection. “Yeah,” he said, “there’s no doubt about the perfection, whether it was evolution or creation; whichever it was.”
Heretics in the field – whatever next?
But they’re all still just birds, jon!
It’s actually what makes me convinced of the strength of evolutionary theory, the absolute precision of organism to niche. And of course it is easy to answer the “chicken and egg” question. Variation must come before adaptation. Show otherwise and you can disprove the theory of evolution.
Well I agree that variation must come before adaptation. I just don’t see how current theory gives natural selection sufficient space to work that precisely and creatively. But ENCODE gives a whole new palette to work with (and a whole lot more paint to spill everywhere).
Having said that, I remember watching a program on hammerhead sharks in which the biologist suggested that the hammerhead probably emerged as a hopeful monster in one generation and had to find a new way of life PDQ. I’ve no idea what variation of evolutionary theory he was working with.
“Just birds”? I’m not sure how you mean that. Einstein’s just a bloke with bad hair.
I was hinting at the creationist canard “but they’re still just dogs”. The nested hierarchy still links birds together as marvellous variations on an avian theme.