Adaptations

So the concept behind the white-tailed deer is that if they wave this bright, white, flag (their tail) at you while running away, you will be so distracted by it, that you won’t chase them and eat them. It’s really amazing these animals have survived as long as they have. I mean when I see a bouncing white tail it looks to me more like a “shoot here for supper” signal than anything else.

But people are not like wild predators. This escape technique probably evolved a long time ago when it distracted a lynx just long enough to keep it from catching the deer in question. Then all those other showy tailed deer, who seemed to be surviving lynx attacks (it could have been a saber-toothed tiger for all I know) better than the others, got together and had many, many showy-tailed babies and a survival adaptation was established.

Now I don’t know about you, but the last thing I think when I see a white-tailed deer go by is, man, I wish I had my gun. But the truth is for humans, that flashing tail is not a deterrent. Still the adaptation obviously worked, for there are a lot of white-tailed deer around. Anyone in New Jersey can tell you how well they have adapted to living among their human neighbors.

This adaptation thing is pretty interesting. It’s not something that happens overnight. It takes many, many generations for a new trait to prove itself in longevity and increased progeny. Only in lower animals like insects can we see a real change in a relatively short period of time. But if you had 1,000 offspring with new generations coming every few weeks you’d adapt pretty fast too. It makes adaptations easier to study in lower animals, but it has its down side. Consider bacteria’s rapid immunity to all the new antibiotics we come up with. Now that’s adaptation baby!

Adaptation is sometimes obvious. In the old coal-burning days in London, the peppered moth was a speckled brown moth that blended into English tree bark perfectly. Then the environmental movement came along and changed pollution standards. Coal was banned in the city and smokestacks were made taller (get those pollutants out into space for goodness sake). Within a decade the trees, once brown from coal smoke, began to take on their natural light colored bark. As the trees lightened, the brown peppered moths stood out against the bark and were easy targets for hungry birds. But lighter moths blended and survived to lay eggs. It’s not hard to imagine that pretty soon all the peppered moths were lighter in color. This is how adaptation works, though in mammals and other vertebrates it takes considerable longer for an adaptation to infiltrate a species.

moth

Some adaptations are easy to follow. Take the skunk, with its very handy built in tear gas. Skunks are part of the mustelid family (often called the weasel family). Mustelids, including mink, weasel and otter all have smelly oil glands like the skunk, but only the skunk has adapted the nifty skill at sharing it with others. Plus anyone who has had the dubious pleasure of sharing with a skunk can confirm that skunk oil is a lot more potent than mink or otter oil. So somewhere along the line, a particularly smelly genetic line of skunks discovered that they could discourage predators by discharging oil from their oil glands at their faces. This was useful to skunks, as they are neither as fast, or agile at escaping predators as their weasel cousins. You can imagine that this smelly, spraying skunk line quickly outnumbered the more polite members of their species. An adaptation was established. This might oversimplify it a tad, but it is essentially how adaptations develop given enough time.

sheri_and_alfalfa

It’s fun to think through how different traits might have adapted. Consider the camel’s long eyelashes and closeable nostrils the next time you are caught in a sandstorm. Or try to find that perfectly camouflaged killdeer nest that the mother with the fake broken wing is making such a fool of herself trying to distract you away from. And how about that uncanny ability of your dog to appear in the kitchen when you open the refrigerator? It’s really rather fascinating.

But not all adaptations are that easy to puzzle out. And that is the great mystery and beauty of nature. Some things you just can’t easily explain. Some adaptations are just too weird. I mean take porcupines for example or sumo wrestlers. I mean there has to be easier ways to survive out there, doesn’t there?

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About Sheri Amsel

Sheri Amsel has degrees in Botany and Zoology from the University of Montana 1980, a Master's Degree in Anatomy, Physiology and Biomedical Illustration from Colorado State University 1987. Ms. Amsel interned at the Smithsonian Institute in 1983 in Scientific Illustration, taught anatomy and biology at three colleges from 1990 - 1997. In addition, Ms. Amsel has published more than 15 nonfiction children's books, two field guides for adults, and illustrated a myriad of books and interpretive displays on nature and science topics. Ms. Amsel has done science programming at more than 300 schools nationally, developed more than 20 educational nature trails in New York State, and coordinates school visits to local nature trails for environmental education programs for the Eddy Foundation, a nonprofit organization dedicated to conservation and habitat preservation. Ms. Amsel created the Exploring Nature Educational Resource website with the hopes of sharing her science and environmental education knowledge and experience with science educators and students worldwide.

One thought on “Adaptations

  1. I always thought the “flag” that white-tailed deer display is to warn others in the herd of danger. The distraction thing makes sense, too, though.

    One distraction mechanism that sticks in my mind is lizards, such as anoles, that have breakaway tails that continue to squirm once broken off in order to distract a predator.

    As for porcupines, I can’t imagine how they evolved their defense (but I can’t imagine how skunks did, either), but it’s very elegant in its simplicity and effectiveness. Hedgehogs, too. We used to see hedgehogs all the time when we lived overseas, and while they are just as impenetrable as a porcupine, at least you can touch them. Not so with porcupines. Saw a guy at the Moscow circus who juggled hedgehogs (without their consent, I’m sure) but he saved the porcupine for the balloon-popping climax of his act.