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Visiting Darwin’s grave ere I die

POSTED August 14, 2009 9:08 p.m.
My Labrador-mix from the dog-pound is quite a mutt, but even so he shows Lab enthusiasm for retrieving sticks I throw into the river. (Just for the record, he’s a specialist and won’t retrieve sticks thrown on land.)  
The best watchdogs I ever had were two Dalmatians. The Dalmatian is an ancient dog, originally bred to loudly sound the alarm if a stranger arrived at the manor in the middle of the night. Dalmatians, as far as I can tell, live by two simple commandments. First: if something happens, a Dalmatian must bark loudly. Second: if Dalmatians are barking, they must keep on barking.   
The simple process of selecting which of our domestic animals gets to reproduce — choosing which critter gets to be the mamas and the papas for the next generation — has long given us humans a fantastic array of domestic dogs, horses, sheep and all the rest. In the 1800s, Charles Darwin had the wit to reason about animals in the wild with our domestic breeds in mind. The core of his idea is termed “natural selection.”  
Natural selection operates not by fences and leashes that keep potential mamas and papas apart in the barnyard and the backyard, but simply by the processes played out in the wild each day. On average, if an animal has a characteristic that’s useful for its environment, it’s more likely to survive (and reproduce if it can). If it does all that, then it’s characteristics are likely to appear in the next generation.
Here’s one example of the process.
Several million years ago, there were elephant-like animals all across Asia. We know about them from the fossils they left behind. They were not exactly the same as the modern African and Indian elephant, but if one walked into your living room tonight you’d definitely say, “There’s an elephant in the room!”   
About two million years ago, global climate changed. The world entered the Ice Age and temperatures became absolutely bitter.   
Many animals may well have died due to the massive climate change, while others likely moved south. But some of the northern elephant species changed, as the fossil record shows. Schoolchildren know the animals that resulted as the woolly mammoth and mastodon, and they left many of their bones, tusks, and pieces of fur behind in parts of North America, Asia and Europe.
It makes sense that woollier coats helped the mammoths survive the massive climate change that had engulfed the Earth. But it can’t be that the mammoths simply wished themselves hairier so that they could stay warm in their new environment. What caused them to change?
Darwin had the wit to see that natural selection was a key to the puzzle. A woolly mammoth that was a bit woollier than his cousins was more likely to survive the bitter winters of the Ice Age. Because he survived, he could reproduce, and his offspring would tend to be woollier, too, just like their daddy. Just as Dalmatians can be selected for endless barking, Mother Nature can select animals that are better suited to their colder environments. Enough change, and we’ve got a new species on our hands.    
Natural selection doesn’t have to work perfectly all the time to be a profound agent of change. One particular very woolly mammoth may have some bad luck and fall down a crevasse in a glacier, snuffing out his potential impact on later generations. But, on average, if woolliness helps mammoths survive bitter climates, it’s likely to become more and more common in the population.  
It’s unfortunate that our culture got mired down in the bog of political conflict about Darwin’s theory. Natural selection surely doesn’t seem controversial from where I sit in a church pew on Sundays, and most major Christian denominations accepted Darwin’s ideas more than a century ago.    
Before the good Lord calls me home, I hope to go to Westminster Abbey in Great Britain. I’d like to pay my respects to Darwin where he lies in a place of honor. And when I kneel down somewhere in that great building, I’ll think of all those long-ago generations of wooly mammoths and the Ice Age in which they lived.  
— Dr. E. Kirsten Peters is a native of the rural Northwest, but was trained as a geologist at Princeton and Harvard. Questions about science or energy for future Rock Docs can be sent to epeters@wsu.edu. This column is a service of the College of Sciences at Washington State University.

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