How Many Times More Sensitive Is A Dolphin's Skin Compared To A Human

Humans have come to fetishize dolphins: their smiles, their penchant for heavy petting, and they imbue their frolicking with moral assertions most one'south duty to live with abandon. These projections endear them to the states.

But the truth almost what'south going on inside a dolphin'due south head has very little to practise with our human being experience. Just as a doctor shudders at colon cleanses, the climatologist at deniers, virtually animal behaviorists blench at farthermost acts of anthropomorphism—the practice of assigning human personality traits to nonhuman animals. The differences between dolphins and humans, that's where the dazzler lies—in the notion that a nonhuman animal could showroom such cognitive complexity and yet be then utterly alien to the states. It shouldn't be surprising, and then, that information technology was dolphin communication that Carl Sagan and his colleagues at the Search for Extraterrestrial Intelligence wanted to study to prepare for contact with extraterrestrial life.

Certain, humans and dolphins aren't as disparate every bit, say, humans and octopus; our last shared ancestor with the latter crawled the Earth about 750 million years agone, as far removed every bit ii creature cousins can be. We diverged from dolphins and whales (collectively called cetaceans) only about 65 one thousand thousand years ago, about as far removed as whatsoever ii mammals can be. (Cetaceans' closest living relative is the hippo, from whom they diverged about 55 million years ago.)

So in order to understand a dolphin'southward experience, assume you know nothing, basically. You'll naturally start to empathize—or at least projection. That's natural. Humans tin can't actually assistance it. Nosotros do it even when nosotros're getting it wrong. And so try to empty your heed. Sit back, relax, and imagine you're weightless. Gravity doesn't affect you like it does those land critters. You motility in all directions—upward, downwardly, left correct, in and out of h2o—all the time. And unlike them, your respiration isn't automated, like a heartbeat or a reflex: To take a breath, you take to brand the conscious choice to notice the edge of the h2o, your home, every five minutes or and so. And considering of that: You lot never sleep. Non really. Ane one-half of your brain is active all the time, even when you rest; you literally slumber with 1 eye open.

Fifty-fifty though your skin is x-20 times thicker than terrestrial animals, information technology's extremely sensitive.

You lot take skilful eyesight, both in and out of the water, which is rare in the animal kingdom. You might come across color simply mayhap not—it's complicated. You lack olfactory nerves, so you don't accept a sense of smell (your air-to-nostril time is exclusively for animate). The jury's still out as to what and how yous taste.

Yous do accept splendid hearing: Your auditory nervus has several times every bit many fibers equally humans, and with each fiber measuring nearly two times thicker, you can hear a range of frequency seven times wider than a human'southward. You lot can fifty-fifty "meet through" things, using sonar: Different materials return audio differently, so y'all can find the fish hiding in the sand, or the shark lurking in the kelp forest. It might even be equally detailed as those sonograms humans show off of their unborn children. In fact you can "run into" a human fetus inside its mother's womb (probably). (Perchance you recognize it as a mammal fetus and swim in to become a closer look, causing humans to beginning a whole "dolphin midwifery" thing, which—only—they need to stop.) It's possible that your senses of hearing and bear on are intertwined: Your jaw, for instance, acts kind of like a tuning fork, helping audio waves up into your "ear".

Even though your skin is 10-xx times thicker than terrestrial animals, it's extremely sensitive. It's just stupid with nerve endings, especially around the fins, genital region (like humans, sort of), and the rostrum (your snout). You lot use it to root for food, but near often to touch other dolphins. Yous use touch to talk. Y'all vocalize, sure, with whistles, screams, chirps, but you utilise your trunk, too—for instance, the meaning of petting via pectoral fins may even transcend species.

Beloved and friendship are human words that mean nil to you. But if yous run across a dolphin yous haven't seen in awhile, you lot remember them—even decades afterward. And when someone in your family dies, yous find. And partnerships certainly abound in your world: Females form "alliances" to have care of immature, which includes defending against male alliances, whose master function oft involves helping each other fight for the correct to mate with females, even perhaps killing the offspring of males from competing alliances. But the rules within these alliances are extremely complicated, the source of manufactures upon articles trying to decipher their structure. Maybe, some humans say, your emotional intelligence is through the roof.

It's possible, for instance, that your socioemotional systems are so circuitous that your brain became a unique shape—or the other way around. Maybe you didn't evolve a prefrontal cortex (which is the role of the brain humans use to assist them regulate their behavior and make decisions). Maybe instead your encephalon adult a structure called the paralimbic cortex, which could be similar, just everything that goes on there is much more than tied to emotion. Information technology's also a controversial possibility that yous have style more than of certain type of brain tissue ("association cortex") that helps sort through sensory input and emotions, and social goings on. Peradventure if humans had more "association cortex" they'd exist more than in tune with each others' emotions. Or maybe, more probable, you lot merely use yours differently than humans exercise.

Maybe you don't fifty-fifty need words. Perchance you don't remember in words or even symbols, just rather in emotion, intent. You and your pod-mates have "signature whistles," patterns that are consistently associated with individuals, used to circulate your identity, mayhap, like a name. You tin can exist taught to sympathize symbols. You lot tin can use symbols, but mayhap y'all don't. Humans communicate nigh entirely via what words they choose, what their faces and (to a much lesser extent) bodies are doing as they speak or don't. But y'all have no face motion. Evolution long ago fused those muscles into the hydrodynamic hull of the ocean'southward fastest mammal. You lot're not grin: You tin can't.

So come on dorsum. Surface from that mental trip to a very generic dolphin-land. Fifty-fifty if you lot could mind-meld with a real dolphin Spock-way, who knows what you would have experienced? Non even dolphins of the same species think identically; individual brains develop differently depending on genetics and circumstance and outcome in different personalities, just like us, our cats and dogs, and probably most of the animal kingdom, and there are 36 species of dolphin, depending on how you count them. All of them, though, live with 360 degrees of sensory information 24 hours a day, two types of sight, a dozen types of sounds, and more than feels than we tin can imagine.

In those terms, maybe they're more than "tuned in" with the world around them, by necessity: a holistic blend of the concrete, sensory, and cognitive, all seamless plenty to remember to go upwardly for air.

Maggie Ryan Sandford is a science communication researcher and media maker. Her writing has appeared in, among others,Smithsonian magazine,ComedyCentral.com, National Geographic, Slate.com, and on National Public Radio's All Things Considered. Follow her on Twitter @Mandford.

The atomic number 82 photograph is courtesy Matthew Baya via Flickr.