Double or Nothing

Nine out of ten Earthlings agree: Nothing beats a hot pair of twins. If you are already attracted to someone, the only thing that can possibly improve their overall hotness is discovering that there is two of them. In fact, that’s the best theory I’ve heard yet to describe why identical twins, as a phenomenon, are so popular in everything from DoubleMint Gum commercials to Playboy spreads: we singletons tend to objectify them as the same person with the advantage of having two bodies. But biologically speaking, does having a clone confer any advantage to you as an individual, or even to you as a species?

There are some questions better left unasked.

First, a primer on twinning. Dizygotic twins, otherwise known as fraternal — or, in the case of two females, which is more common, sororal — twins are the product of two separate eggs, and form in two separate placentas. In humans, having any kind of twin is a gamble — even a fraternal twin is five to seven times more likely to die in the womb than a singleton fetus, and at much higher risk of mental retardation, learning disabilities, respiratory problems, cerebral palsy, and a host of other health problems. But in the animal world, di- or polyzygotic young are the norm; we call them litters. In a cruel world, a species usually cannot count on only children to further itself, and so hedges its bets with siblings.

With dizygotic twins, it is possible to produce siblings with different genetic defects.

More rare in humans and other animals are monozygotic twins; that is, identical twins developed from a single egg and placenta. You might be a twin or know a twin who looks very different from his or her womb-mate, as environmental factors such as lifestyle choices and childhood illnesses cause certain genes to express themselves in one twin and not another. Identical twins may share the same DNA, but don’t bear the same fingerprints. I’m a singleton myself, but sometimes I imagine a hypothetical twin brother I might have had who works out, is a vegetarian, and hasn’t been drinking coffee daily since age 14. He is 6’1″, physically fit, has a normal haircut, and I secretly hate his guts.

Happy as he was for his brother Paul, Morgan Hamm had to wonder if he took the silver medal because he had eaten a second slice of birthday cake at age 9.

Twins in human reproduction seem to be a happy accident; after all, twins make up a mere 2% of the world’s population, with identical twins or triplets constituting only 8 percent of those, or 0.2% of all people. But what about species in which twinnage is fairly common? Can producing two or more genetically identical offspring be a successful reproductive strategy? At first glance, the animals that frequently have twins have little in common: ferrets, cats, sheep and deer all frequently bear twins, and polar bears almost exclusively do. But for popping out passels of identical bundles of joy, one mammal has the rest beat: the nine-banded armadillo, which as a rule produces litters of identical quadruplets.

Nothing beats a hot pair of twins, except two hot pairs of twins.

Stranglehold

Ficus. Its name is synonymous with low-maintenance, unobtrusive office plants. But in the wide Ficus genus, there are a few species of fig trees that are anything but tame. In fact, they have a predilection for death and domination. This story is about two distinctly different creatures whose lives are inextricably linked: the strangler fig and the fig wasp. It is a story about sex and murder in Florida. Mostly, it is a story about the mentality and biology of control. One of these partners-in-crime kills by slowly choking the life from its victims, and the other is its accomplice, furthering its domination of the forest with rape and incest. To be sure, you’ll never look at Fig Newtons the same way again.

Radioactive

The world is watching in horror as Japan begins to suffer the effects of massive radiation poisoning following the earthquake’s destruction of several nuclear reactors. Our primary concerns right now are for the beleaguered people of Japan as they struggle to survive and contain this catastrophe. But once the immediate threat has passed, as we all pray it will, the question that must be answered is no less important, as it is far further-reaching: What will the impact of the irradiated sites be on the environment? And what effect will nuclear radiation have on the local wildlife?

First, a primer on radioactive decay for those who are neither science-minded nor paranoid survivalists with their own Spam collection. Radioactivity is the release of particles from the nucleus of an atom as it loses energy. We receive most of our Daily Recommended Value of radiation directly from the sun, or from the Earth, primarily as radon gas. We are constantly bombarded with cosmic radiation. It’s what mutates our genes and moves evolution forward, and also gives you a wicked tan. In fact, it’s all we can do to shield ourselves from normal levels of radiation, so the particles streaming from decaying atoms of a heavy isotope of uranium or plutonium are especially dangerous. Alpha particles — bundles of two protons and two neutrons shooting from the nucleus as the atom decays — are relatively harmless, as they’re too slow to penetrate the skin. Beta particles, which are electrons, are a hundred times faster, but are too small to penetrate skin. But ingest an element that’s shedding these particles, and they will bounce around in your cells like ricocheting bullets, destroying all the DNA in their path. And as far as radiation that can penetrate your skin, like electromagnetic gamma rays, I think we all know what happens when you play with that stuff.

Overly ponderous yet ultimately respectable Ang Lee movies?

If, like me, your first exposure to the concept of radioactivity comes from comic books, let’s set the record straight. While radiation can be used to do things like destroy cancer, rumors of its magical healing properties have been greatly exaggerated. My favorite example is the radium-laced “tonic water” jars that were briefly popular in the beginning of the 20th century, according to the belief that drinking irradiated water gave you vim and vigor. American industrialist tycoon Eben Byers was a promoter of this revivifying elixir, and had a bottle every day. When he died in 1932, the Wall Street Journal headline read, “The Radium Water Worked Fine Until His Jaw Came Off.” Having ingested more than three times the usual lethal dose of radiation over the course of his lifetime, he was buried in a lead-lined coffin.

Some preferred to take all their nuclear radiation in one big dose.

And there is the sad truth about radiation. Subject an iguana to radioactivity, and it doesn’t grow into Godzilla; it just pukes and dies. A bite from a radioactive spider is less likely to give you spider-like powers than it is to endow you with a superhuman inability to bear children. Coat turtles in radioactive goo, and they don’t turn into ninjas. They just get cancer.

Godzilla: Not Realistic.

So what might happen to the irradiated animals of Japan? To get a glimpse into the potential danger of radioactive wildlife, we don’t need to consult science fiction stories or comic books. We just need to examine the results of the 1986 Chernobyl disaster and its legacy, including terrifying and true story of the packs of radioactive wild boars causing havoc in Germany today.

Dead Reckoning

“It’s a poor sort of memory that only works backwards,” wrote Lewis Carroll in Through the Looking Glass. But it’s not true when that backwards-thinking memory is spectacular. Those few with truly eidetic memories, also called photographic memories, have mixed feelings about the power, but there’s no arguing that the ability isn’t incredible. Witness Stephen Wiltshire, an autistic savant and architectural artist who can draw an entire city skyline from memory from just one helicopter ride, or a cathedral after a glance. Or remember the late Kim Peek, the inspiration for Dustin Hoffman’s character in Rain Man, who was estimated to have the complete content of 12,000 books committed to memory. Truly, memory is the library of the mind.

Then there are more or less fortunate people with hyperthymesia, or perfect autobiographical memory. Instead of memorizing the names and numbers of everyone in the phonebook, a person with hyperthymesia can recall with unblinking clarity everything they’ve ever experienced in their life. There have only been six documented cases of hyperthymesia in the world, but in each case, the patient can remember every detail of every day they’ve lived: what color shirt they wore, the faces of people who passed them in traffic, the arbitrary shapes of clouds. Every slight, every embarrassment, every victory, every heartbreaking moment. Forgetfulness is the gardener of memory, and hyperthymetics live in an unweeded wilderness of places, times, and emotions. In Jorge Luis Borges’ short story Funes el memorioso, the author invents a character with such a remarkable memory that he can relive a previous day’s events in real time, which, of course, takes an entire day to do. Funes is cursed by the inability to understand abstractions; able to remember absolutely every experience in crystal clear detail, he cannot understand the need to generalize. Poetry and dreams are beyond him. Every moment in the past is just as real to him as the current one, and his life one unbroken and contiguous chain of events interrupted only by sleep.

I remember a man on the streets of Prague who would make money from tourists by betting them that he could tell them their area code with only the name of their hometown. What I didn’t realize then was that anyone is capable of such feats of memorization, with practice. Mnemonists can memorize the sequence of a deck of shuffled playing cards in under 25 seconds, or the names of 1,500 conference attendees after hearing them once. Humans can do this by the use of mnemonic devices: acronyms, memory journeys, and storytelling. Our species is lousy at remembering abstractions — the opposite of memory, you’ll recall — but pretty good at remembering images and places. So a mnemonist will associate numbers (which are abstract concepts) with pictures and turn the first 100,000 decimal places of pi into a kind of mental comic book. Or they will take every line from The Iliad, turn each line into an image, and store each image somewhere in a “memory palace” (the remembrance of a well-known building, like one’s home) where the images can be “collected” in sequence. The spatial memory that helps you navigate your world is actually pretty keen; we lab rats have figured out the maze of our own construction quite nicely. But when it comes to spatial memory, there’s at least one animal who makes humans look like babes in the woods.

You look a little lost, dear.

Dog Whistles & Subwoofers

Last Friday’s horrific earthquake and tsunami in Japan got me thinking about the last major tsunami in memory, the cataclysmic Indian Ocean tsunami of 2004. Much was made of the fact that, though entire towns were leveled by the flood, very few wild animals perished. It seems that about eight hours before the tsunami hit the shore, there was a massive migration of animals to higher ground. What tipped them off? The infrasonic sound of the approaching wave rumbling under their feet. And when I think of infrasound, the first animal I think of is the giraffe.

Really? I don't remember saying anything.

Why the giraffe? Why not a well-known basso profundo like the elephant? I have written about giraffes before, mainly in the context of how incredibly gay they are. But I’ve never written about their songs.

It was thought for centuries that giraffes were practically mute. Like rabbits, they were only known to make sounds in times of distress or courtship: whinnies, bleats, snorts, coughs, and even the occasional groan, mew, or bellow. But it was presumed that, for the most part, giraffes were simply very tall wallflowers. Then, in 1998, a bioacoustician named Elizabeth von Muggenthaler borrowed some high-tech equipment and discovered that giraffes are actually extremely talkative. They’re simply having a conversation below our range of hearing.

That giraffes are basses should have been obvious from the necks.

Water Into Wine

The Son of Man. The Lamb of God. The King of Kings. The Knave of Hearts. The Sultan of Swat. Jesus of Nazareth, also known as the Prince of Peace, and in America, the God of War, was said to perform a string of miracles at the beach town of Tiberias on the Sea of Galilee in Israel. One of them involved catching a great deal of fish with one net. Another, feeding several thousand people with very little food. And yet another involved walking on water to meet a boat full of his disciples, who were caught in a sudden storm.

"Duuuuude! Watch out for that waaaaaaave!"

Now, Clarke’s Third Law states that “any sufficiently advanced technology is indistinguishable from magic.” So nowadays, the miracle of the modern fishing industry, with its deep-sea trawlers, 150-mile longlines, and space-age tracking and echolocation technology, ensure that our nets can catch hundreds of thousands of fish at a time. (Though not for much longer.) And genetic engineering, bolstered by mechanized farming and artificial fertilizers, ensures we can feed the multitudes. (Though not for much longer.) But biologically and technologically speaking, how miraculous is it to walk on water?

Stroke! Stroke! Stroke!

Not very, if you’ve got the right tools, and the right size. The most classic example of animal locomotion on the water’s surface is the water striders, or water skaters, or water scooters, or any of the other collective names for these 500 species of insects that make up the Gerridae family. They are hunters that use surface tension to their advantage; where prey might swim, they float like a bubble. Their short front legs are for grabbing, their middle pair for “skating,” and the hind pair act as rudders. The secret to their unsinkability is the hydrophobic hairs on their legs. Each leg is covered in thousands of fine filaments called microsetae that spread the weight out on the water’s electric “skin” of surface tension, and the grooves in each filament trap tiny air bubbles which add to their buoyancy. So powerful is the effect that a water strider could carry fifteen times its own weight and still remain afloat, and a few species have even adapted to walk the waves of the open ocean.

The ability to walk on water kind of goes to their heads.

But it’s not only insects that have the ability to walk on water. A few reptiles have also evolved to stay high and dry. And more advanced insects have discovered not just how to walk on water, but how to turn water into wine.

Power Plant

Lace up your boots and follow me on a nature hike through these low Berkshire mountains of Western New England in early March. The air is thick with sunlight, as the red oak trees and alders haven’t yet leafed out, and their branches are just the latticework of a window on the sky. The ground still has a cover of snow, but you can smell the melting water beneath it as last Autumn’s leaves exhale a musty yet bread-like scent. Except for a few cedars, nothing is green yet. Nothing, except for some ugly, purple-green spikes sticking out of the snow. Come to think of it, they’re not so much sticking out as they are simply uncovered, as if the snow was too repulsed to touch them. And come to think of it, it’s not just fresh snowmelt you’re smelling. The woods have taken on the distinctive smell of buttcheese. You approach the ugly, stinky butt flowers.

Now, stick your finger in it.

And wiggle it around on my spadix while you're at it.

Baby Fat

So, how badly do you wish you could have just slept through this entire winter? There are many ways to hibernate, but one style of hibernation stands out as especially advantageous. You never wake up, you give birth while you’re asleep, and perhaps best of all, you lose your body fat without losing your muscle. Imagine being able to eat as much as you want, go to sleep, and wake up ripped. There are only two animals we know of that can burn significant amounts of fat without losing muscle mass. One is a baby. The other, a bear.

Which is basically a baby.

It is hotly debated by experts whether what bears do can be called hibernation. After reviewing the evidence, I stand with those who say it is. It’s simply a hibernation for the big-boned fellas. See, the little guys, like chipmunks, hibernate by lowering their body temperature dramatically. A bat, for example, can lower its body temperature almost to the freezing point. But they keep a food store handy, and every few days they heat up and wake up to eat and defecate before falling back into torpor. A bear, on the other hand, slows its metabolism a great deal, but doesn’t chill its body temperature appreciably. So if you were spooned by a sleeping grizzly, you’d still be nice and toasty, if a little unsafe. What’s more, though a bear can go from being a deeply unconscious heap of fur to 700 lbs of bitchy fury in about 30 seconds when disturbed — again, spoon carefully — it can go up to seven and a half months without waking up once. It recycles its urine for hydration, and is the only animal known to be able to transform urea — the yellow, poisonous part of urine which must be excreted from the body — back into valuable protein. As for defecation, the bear creates a dense “fecal plug” of intestinal secretions and dried poop that corks up the bunghole to prevent any “accidents.”

I've been asleep since November, I haven't eaten or shitted for five months, I woke up with two kids I don't remember having, and I haven't had my coffee yet.

Resurrection Fern

I have a resurrection plant. I sometimes call it a resurrection fern, even though I know that’s a different plant entirely; mine is Selaginella lepidophylla, a club-moss native to the American Southwest, while true resurrection ferns are Polypoidium polypolioides, native to the American South. But both the moss and the fern, as well as a few other plants in the world, perform the same incredible feat: they return to life from the brink of death.

Both resurrection moss and fern live with little to begin with. The moss is a desert plant, sometimes called flor de piedra, the stone flower. During periods of drought, the resurrection plant curls up into a tight little fist, brown and nearly desiccated, for all appearances dead. It becomes a tumbleweed, rolling with the desert wind in search of the next patch of mud. Finding something to drink, a remarkable change takes place: its cells rehydrate in a mere hour or two, and the fist opens into a hand. A few hours later, it becomes green again. The dormant machinery that powers it, all the organelles of its chloroplasts, revive and whir into action. Sunlight becomes sunlight again. Just a kiss of moisture, and it walks out of its own grave. The resurrection plant may tumble around the desert lifelessly for a century waiting for such a blessing.

Five Feet High and Rising

The creek behind my uncle’s house here in Western Ohio is flooding; normally a laconic and nameless little tributary with quietly dipping mallards, last night’s thunderstorm and rapidly melting snow has raised the water level almost twelve feet and transformed it into a swollen, churning torrent. As I sit here watching the lawn furniture and Fisher Price playsets rush downstream, I thought it’d be appropriate to talk about animals for whom floods are home.

I’ve written before about the flooded forests of the Amazon basin, the Amazon river dolphin in particular, but it’s worth another visit. The Amazon is sometimes referred to as the River Sea, and the reason why becomes clear when the water level rises 30 feet and covers three times its already substantial area. During the Spring floods, a gondola navigating the trees in the rainforest might come upon a pair of giant otters chasing each other through the water, or glide into a mysterious pool of shimmering gold which, on closer inspection, turns out to be a school of piranhas. Here in the varzea, the underwater forest, the Amazonian manatee does the dead man’s float while grazing on submerged meadows, and the anaconda rolls like water boiling. And if you’re lucky, you may find the dragon of the Amazon: the arapaima.