Figure 1: Even I am grossed out enough by this picture to reconsider the merits of the weasel. Figure from: http://en.wikipedia.org/wiki/File:Donnola_vs_lepre.JPG
In fourth grade, my classmates and I were assigned a project. We were to research our favorite animal at the local library, and give a presentation on this animal to the rest of the class. When it was time for our presentations, most of my classmates excitedly gabbed about lions, tigers, humpback whales, or dolphins. I went in front of the class to present my favorite animal, the weasel.
Many of my classmates snickered at this choice. The weasel was not a majestic king of an ecosystem and never entertained anyone at Sea World. Indeed, weasels have pointy teeth, which they use to snap through the necks of adorable bunnies, and are almost universally seen as a bad omen. But there was one trait of the weasel that I found fascinating. Every winter, the weasel would shed its short coarse brown coat of fur to reveal thick soft white fur.
The need for this evolution of this ability is simple. Predators would have a hard time spotting a white coat against a blanket of snow in the winter, and difficulty spotting a brown coat against the summer wooded dirt ground. So weasels have evolved to contain an unconscious biological gauge that would measure the average amount of daylight and average daily temperature. When this gauge read “autumn” the weasel would start to turn white.
Most of the other facts about weasels are mundane. They have the habits of typical rodents. But this ability to change a winter fur coat every winter and summer amazed me. It was a metamorphosis!
Figure 2: The sly weasel knows a seasonal change of color may trick its enemies. Figure from: http://io9.com/5959772/how-and-why-animals-change-color-with-the-seasons
Many critters have the ability to change their appearance. Weasels, rabbits, grouse, frogs, even spiders can transform seasonally into new vibrant hues.1 But some metamorphosing organisms surpass a simple superficial makeover. In fact, these organisms transform to an extreme level that treads the line of existing as a single entity.
Take the common caterpillar. Caterpillars spin a cocoon shell around their body in autumn, sleep in the shell for months, then bust through the shell in the spring, emerging as a vibrant butterfly. For this reason, butterflies have long represented change and renewal – the primary reason they adorn the backs of many spring-breakers as unfortunate tattoos.
Figure 3: The butterfly, beautiful and magically able to metamorphose. Figure from: http://www.fanpop.com/clubs/yorkshire_rose/images/15990936/title/butterflies-wallpaper
Consider shedding your entire body to reveal a completely new creature. As one reporter for Radiolab adeptly comments, “It’s like if you would skin me, and my 70 year old self was inside of me.”
Figure 4: One can only assume the robots will decompose in their cocoons. Figure from http://xkcd.com/1336/
While the transformation of a caterpillar-to-butterfly is amazing, the ability to metamorphose into an entirely different organism is seen even in simple, single-cell organisms, like bacteria. Bacteria use this transforming ability as an “escape hatch” in tough situations.
BTW
* Not all bacteria form endospores, only pesky bacteria that seem impossible to destroy. Whenever you want to kill a colony of bacteria, these organisms merely pack up an endospore and wait until you end your attack. Once the coast is clear, they repopulate like a crafty bunch of jagoffs.
Through this method, bacteria not only metamorphose, but are constantly reborn, allowing them to continuously dodge death.
Figure 6: The phoenix may be a mythical bird, but real-life organisms have the ability to arise anew from the ashes. Figure from from http://media.swarthmore.edu/bulletin/?p=117
I enjoyed reading your bit about butterflies and endospores.
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This was a great read! Throughly enjoyed 🙂
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