Mr. Write's Page

The Chaos of Evolution

Science, as you know, is willing to change its conclusions as new evidence warrants. Well, while I wasn’t paying attention, science made a whopper of a change about the nature of evolution.

As Darwin explained, evolution occurs through the process of natural selection. Namely, the fittest organisms survive, reproduce, and pass on their traits to the next generation. The idea also took root that the process unfolds as a rather neat and orderly progression, as if the species is changing by climbing a ladder, moving onward and upward.

That concept — that evolution is largely progressive — is now out the window. Instead, experts think evolution is less like a ladder and more like a big, gnarly tree, with lots of branches and numerous dead ends everywhere.

The new thinking is that a species evolves to adapt to a specific, immediate environment. For example, researchers once believed that the first horses had four toes, then evolved to three, then two, and finally to hooves.

More likely, toed horses evolved as more suitable in various marshy habitats, and hoofed horses evolved to navigate dry, rocky ground. Maybe one evolved from the other, maybe it didn’t. Think chaos, not orderliness.

Learning this made my head swim, but it makes sense. And it’s wonderfully objective.

I love science.

The Chase

My dog Jake sees deer all the time as they pass through the woods behind our house. It’s a thrill for him, but he’s inside a fence. You can bet he aches to be free, to give chase as nature intended, galloping in pursuit through the trees, unrestrained by fence or leash.

Not long ago, he got his wish. He and I went walking at Jefferson Elementary School on a Saturday, when he could go off-leash. The school property backs up to a multiple-acre woods.

As we walked along the edge of the woods, Jake suddenly froze and stared into the trees. Seconds later, a deer bolted and took flight. In a heartbeat, Jake was after it.

The chase lasted 10 or 15 seconds. Ultimately, 75 or so yards away, the deer leapt a fence into the safety of someone’s back yard. The drama was over.

When Jake came trotting back out of the woods, he was panting with excitement and exhaustion. A beaming dog smile was on his face.

Chickens

The chicken (Gallus gallus domesticus) is the planet’s most common bird and one of the most widespread of domestic animals. More than 50 billion cluckers are raised annually as a source of meat and eggs. They are a crucial and relatively low-maintenance food source worldwide.

The modern chicken is a descendant of junglefowl that evolved on the Indian subcontinent about 8,000 years ago. Man has raised domestic chickens since the time of the ancient Greeks and Egyptians.

Early ocean-going explorers, including the Vikings, helped introduce chickens to all parts of the world. Typically, live chickens were kept on ships as part of the crew’s food supply, and the birds often were traded in foreign ports for needed supplies.

The origin of chickens in the Americas? Christopher Columbus introduced them here on his second voyage in 1493.