Your dog learned the most effective way to shake water off: by evolution, maybe. Maybe evolution did other things, too.
Spin-Dry the Dog
Anyone with a dog has been amused or amazed at how well they shake water off after coming out of the pool or lake. The shakes start at the head and move like a spin-drying machine down to the tail. Did you know most mammals, except humans, have the same app pre-installed?
David Hu at Georgia Tech decided to take his students on a science safari and find out the evolution of the doggy shake, according to PhysOrg, “Planet of the Apes: Furry mammals evolved a tuned spin dry.” What they found was pretty remarkable: “The seemingly casual jiggle imparts enough centrifugal force to expel 70 percent of the water in his coat in a fraction of a second.” They put stickers on dogs to measure the action, and found about a 30-degree angle of shake.
The team watched 30 other mammals, from “mice, rats, cats, goats, sheep, lions, tigers, bears, and giant pandas” do a similar shake, despite being widely separated geographically. Smaller animals have to shake faster to get the same centrifugal drying effect, but the behavior is similar. It’s not just the shaking that does the job; the skin is also loose enough to impart the energy to the fur. Good thing; animals could face hypothermia if they can’t get the water away from their skin fast enough.
The original paper on the Royal Society website Aug. 17 (open access) had very little to say about evolution: just one mention in passing, that “Many animals evolved physical adaptations to minimize infiltration of water into their furs or feathers.” The PhysOrg article, by contrast, seemed obsessed with saying how this behavior evolved. It brought in Frank Fish as chief storyteller:
Shaking is a useful adaptation, but did it show up in some ancestral mammal millions of years ago, or did it evolve independently in different lines? That’s hard to say, said evolutionary biologist Frank Fish of West Chester University. Fish said mammals probably co-opted the ability to shake, which originated far back in the evolutionary tree. Sharks, for example, do some fast twisting to help them tear up their prey. “We can see the ability to twist all the way back to the first vertebrate.” Since evolution is basically a descent by modification, he said, mammals probably inherited the ability to shake from distant ancestors, and then modified it as a way to get dry.
Teleological language is, unfortunately for Fish, verboten in evolutionary explanations. Fish was then challenged with the fact that humans don’t do the wet doggy shake (try it; it’s hard). He extended his story thus: “Humans don’t have fur, so perhaps our ancestors lost the ability somewhere along the evolutionary line. There’s also one type of hairless guinea pig that doesn’t shake off water, he said.” Evolutionary loss, though, does not help explain the origin of the trait.
The authors in the Royal Society paper, meanwhile, seemed more interested in what human engineers can learn from the iDog Shake app. It might even help JPL with its next Mars rover:
Water repellency has previously been viewed as a static property of surfaces such as plant leaves and insect cuticle. An equally important trait is dynamic water repellency, whereby muscular energy is applied to remove water. This may have use in sensor design. For example, digital cameras already rely upon internal shakers for removing dust from sensors. Such functionality may have improved the capability of the Mars Rover, which suffered reduced power from the accumulation of dust on its solar panels. In the future, self-cleaning and self-drying may arise as an important capability for cameras and other equipment subject to wet or dusty conditions.
Count the Cubs
Bears do the shake, but they can count, too. National Geographic said they can count as well as apes. Right off the bat, the evolutionary story had to make its entrance: “the black bear (file picture) may have evolved its smarts to find food.” This begs the question why all the other mammals needing to find food (presumably, all of them) didn’t “evolve” equivalent smarts.
To reporter Christine Dell’Amore, though, it was perfectly natural: “It makes sense that bears would be smart—as loner omnivores, the animals must problem solve to root out a variety of food sources,” she said, leaving readers wondering if a need is sufficient to generate beneficial mutations for natural selection. More practically, though, “the finding may open up possibilities for comparing the cognitive abilities of bears and primates,” she ended. Maybe evolutionists will decide humans evolved from bears, if not the Clark’s nutcracker (2/17/2004).
Hold the Mustard Evolution
When you see a science article start with “The evolution of…,” you can be fairly sure a just-so story is coming. “The evolution of the mustard’s spice” is PhysOrg’s latest entry. “The tangy taste a mustard plant develops to discourage insect predators can be the difference between life and death for the plants,” the summary states. “A new study has used this trait and its regional variations to conquer the difficult task of measuring the evolution of complex traits in a natural environment.”
So did the evolutionists from Duke University explain why mustard “developed” this tangy taste, but the watermelon did not? Did they explain why insects didn’t develop a taste for mustard in the meantime? No; first, we are told in the article why humans don’t douse their hot dogs with mustard (at least, normal humans don’t), and it’s not to keep the insects away: “Mustard plants produce a spicy chemical intended to discourage insects from eating them lest they suffer a bad case of heartburn, and it has essentially the same effect on us.”
This is a strange statement, considering the widespread attraction for hot chilis among masochistic people. In the end, even though the scientists conjured up amino acids related to spice development in the 3,000 years that supposedly separates mustard from the lab plant Arabidopsis, all the article offered was future hope and a pun: “We finally have the tools to find the genes and to understand their influence on physiology and fitness, and that’s pretty cool.”
A Rose Arose, Evolution Knows
Double flowers are the delight of gardeners, but most natural flowers, like wild roses, are single. PhysOrg offers its readers a “glimpse into the evolution of flowering plants” in its report on work by researchers at the University of Washington. So what’s the glimpse? Well, readers are told that evolution is an entrepreneur:
“The flower is one of the key innovations of flowering plants. It allowed flowering plants to coevolve with pollinators – mainly insects, but other animals as well – and use those pollinators for reproduction,” [Verónica] Di Stilio said. “Many scientists are interested in finding the genetic underpinnings of flower diversification. Just how flowering plants become so species rich in such a relatively short period of geologic time has been a question since Darwin.”
For inquiring minds, it is not very helpful to find that evolutionists are still working on a 153-year-old question. Anything more specific? Actually, yes; readers are told that “scientists have proved the same class of genes” identified in the lab plant Arabidopsis “is at work in a representative of a more ancient plant lineage, offering a glimpse further back into the evolutionary development of flowers.” But that’s not really evolution; that’s stasis. Di Stilio said so: “It’s pretty amazing that Arabidopsis and Thalictrum, the plant we studied, have genes that do the exact same kind of things in spite of the millions of years of evolution that separates the two species.”
Other than a brief mention of jumping genes and mutants that produce double flowers in the lab, the article never really got around to offering the “glimpse into the evolution of flowering plants” the headline promised.
Has there ever been a “scientific” theory more useless and unproductive than evolution? It’s unproductive in the sense of never providing firm answers even after 153-year long efforts. It’s very productive as a motivator for research, we must admit; who wouldn’t be attracted to the possibility of telling just-so stories in the name of science? Time to re-read the 12/22/2003 commentary on what Darwin did to the science lab.