Category Archives: Writing

A Tribute to Thembi: Miles per Pound of Trees

On March 13, one of the elephants I who allowed me into her life died unexpectedly of colic and a heart attack.  I’ve written extensively about Thembi and her herd mates.  This is one of the pieces.

 

Diamond on forehead 2

Thembi, she of the evenly matched ears, long-lashed eyes, and diamond-shaped scar on the bridge of her nose, farts as she walks.  Big, burbling farts.

All the trees, grasses and leaves Thembi eats gather in her 10-gallon stomach, which is pretty much just a holding area.  From her stomach, roughage travels into her small intestine and then on into her large intestine.  Joining the two intestines is a junction called a cecum, where digestion actually takes place.  Her cecum is filled with billions of microbes, just like most mammals, including us.  The microbes break down the cellulose of leaves and trees into soluble carbohydrates Thembi can digest, but the process also gives her enough methane gas to power a car 20 miles each day.

I wonder, as I walk behind her, just how one could harness this gassy natural resource.  I live at the edge of a small town.  Twenty miles would more than cover my daily errands.  I imagine exhaust fumes smelling like fermenting grass.  I imagine driving down highways inhaling the scent of mulched trees.

I wonder, as I walk behind her, why I think of such things.

Percolating along, Thembi lifts her tail and farts again.  It’s a stupendous displacement of air.  In this just-right light, I can actually see this fart.  It looks like heat waves blasting from the back of a jet engine.

One advantage of Thembi’s size is food efficiency, miles per pound of trees.  An elephant eats four to seven percent of its body weight each day – four hundred to six hundred pounds of vegetation.  Mice eat a twenty-five percent of their weight daily and hummingbirds two times their own weight, or two hundred percent.  If hummingbirds ate trees, the forests of the world would already be gone.  Pound for pound, Thembi needs far less food than rodents or birds.  And with her size comes another advantage over smaller creatures – a longer life span.

We humans, with our penchant for measurements, have conjured up a precise formula for figuring out things like longer life spans.  The formula is called quarter-power-scaling.  A cat is about 100 times more massive than a mouse.  To calculate the cat’s age, take the square root of 100, which is ten, and then the square root of 10, which is 3.2.  The lifespan of a mouse is around 800 days, or just over two years.  Multiply 800 by 3.2.  The result is 2,560 days, or seven years, the average lifespan of a cat.

However, if a cat’s metabolic rate was 100 times faster than that of the mouse, all cats everywhere would spontaneously combust into feline fireballs.  Oddly enough, heart rate, the engine that drives the cat to chase the mouse, scales to the same formula, but in the opposite direction, to the minus quarter-power.  The resting heart rate for a mouse is 500 beats per minute.  Divide that by 3.2 and you have the average heart rate for a cat, around 156 beats per minute.

An elephant’s resting heart rate is a placid thirty-five beats per minute and a bit higher, around forty, when excited.  While the jittery mouse lives just over two years,  an elephant lives around sixty-five years, certainly long enough to power my car for the rest of my life.

 

Hearts

Heart shapes can be found in nature, if you’re lucky enough to see one.  There’s a heart on this elephant’s trunk, a ridge of skin that feels like fine shoe leather.  One of his wrinkles pierces the lower third of this heart shape, from left to right, straight as an arrow.  His real heart hangs between his breastbone and ribs, a little to the left, just like mine does.  But instead of having a heart with a single point, an elephant’s heart has two points at its apex – so it’s the wrinkled outline of a human heart that he carries on his trunk.

 

The human heart is approximately five inches long, three-and-a-half inches wide and shaped like a pulsing cone.  It is the only muscle in my body that acts on its own – my heartbeat doesn’t need any messages from my brain.  The cells in my heart tissue involuntarily constrict, all together, all at once, over and over, a soft perpetual-motion machine.  Rip my heart from my body, chop it into pieces, immerse the pieces in a saline solution, and then give them a small jolt of electricity.  The remnants of my cardiac muscle will contract . . . contract . . .  contract – all on their own, sometimes for hours.

It’s designed to be strong, our hearts.

 

 

A World Older Than Ours

 

grey-lourie-copy

Grey Lourie, photograph by Cheryl Merrill

For long periods of time not one of us with the elephants speaks a single word. Plump, babbling, feather-brained guinea fowl run ahead of us in clumps. Their noggins perch atop impossibly skinny blue necks and look professionally shrunk by headhunters. The spooky laugh of a single hyena crawls in from the distance.

Sweat trickles from under my hat. No matter how many times I gaze ahead, the path remains the same two dusty ruts in the tall, lion-colored grass. Seed heads from dry stalks pop like tiny finger snaps in the heat. Sand fine as cake flower powders my boots, and I gasp as though I have gills.

As we trudge along, I catch a glimpse of a “go-away” bird, a Gray lourie, springing along the branches over my head. He leans down and reproaches us for being foolish enough to be out in the mid-day sun. Go-wheyyyyyyy, go-wan. Go-wheyyyyyyy. The lourie nods his pronounced head crest at us. Go-wheyyy. Wheyyyyy. Go-wan. Go-wheyyyyyy.

Bleached by the sun, the sky is no longer blue.   As we pass near a marshy waterhole, two blacksmith plovers bounce up and down, their call mimicking smithies tapping on metal: Klink!Klink-Klink!

In this season, the soundscape around me is filled with dry cracklings. With crickets who rasp their legs together and listen to each other with ears on their tibias. With the scrape of our footsteps. With the buzz of small flies seeking moisture at the corners of my eyes.

What would it be like to think without words and recognize shapes without names? But I hear these words in my head as I think them.

Later, in the afternoon, we flush a warthog family. One of the piglets stops and looks over his shoulder at me.

 

piglet

Warthog piglet, photograph by Cheryl Merrill

Beauty

photograph by Cheryl Merrill

photograph by Cheryl Merrill

 

When I least expect it, Beauty fells me with a roundhouse right, pummels me with soft fists, dazzles me with her quick feet. Sometimes it’s a glancing blow to the chin; sometimes she doubles me up by a quick swing to the solar plexus.   Right, left, right, left – she’s danced me round and round the ring until I’ve lost my breath. She’s left me in my corner, dazed and gasping. She’s held me in a clinch, face to face, with nothing more to say. To some Beauty is just another heavyweight contender, but in bouts with me she’s always the champ, always the champ.

In the Pawprints of Lions, Part Three

“Today we track lion on foot,” Syd says. It’s our final test, the one that lets us know whether we’ll graduate or not from our game-ranger course.

Our small band climbs from the Rover and starts surveying the ground. There are lion tracks here, all right.

“Which way?” Syd asks. We point variously in the same general direction. “Okay, ready?”

We scuff our feet and look around. Syd hefts the rifle from its rack on the dash and our eyes follow his motions as he loads it. That clenched spot in my chest relaxes a little.

Syd and Bernardo usher our silent group away from the road and into the bush as we follow the tracks. Bernardo takes up the rear.

“I am here to stop you from running,” he says with a small smile. Eight people marching in a line and stepping on each other’s heels are not easily identifiable as prey to a lion. But any single one of us dashing way from the group would trigger a hunting response: “Look! Breakfast! And it’s fat and slow!”

We step literally in the lions’ tracks. They are about three-fourths the length of my boots. They are so fresh we can see where the claws have sunk into the sand and made deep slash marks at the front of their pads.

Slowly we make our way through mixed scrub and across pockets of dry, withered grass, stopping frequently to listen for the calls of francolins and baboons, the early-warning radar for lions.

Syd picks up a handful of sand and lets it fall through his fingers, testing. A fluttering wind blows from the right direction, into our faces. If warned by our smell, the lions might decide to swing around behind and follow us. Bernardo keeps glancing backwards, as do I, the last one but for him in our column. Even though it’s fall and many of the scrub thorns have lost their leaves, we can’t see very far ahead. Syd and Bernardo occasionally confer back and forth in low voices, speaking in Shangaan. We probably don’t really need to know what they are saying.

Just past several gullies gouged into the sand by rain, the tracks disappear into a thicket. Syd stops and listens intently, then sweeps his arm to the right. We bypass the thicket, perfect for ambush, and see if lions have emerged on the other side.

In the open, grassy area beyond, our line bumps to a halt. “See them?” Syd asks.

photograph by Cheryl Merrill

photograph by Cheryl Merrill

As if on cue, two heads pop up.

Luckily, even though my heart leaps, my legs do not.

The lionesses are under trees on the far side of the field. They are lying down, but our invasion has made them curious. They stare at us, open-mouthed, little question marks nearly visible above their heads. The whir of a camera reminds me that mine is dangling around my neck. Through its telephoto the lions look less dangerous, more relaxed, squinting at us.

Then, off to the right, another lion roars and Syd’s eyes widen in surprise. A low “Tsssssss,” escapes between his teeth. There are more lions here than we have seen tracks for. Everyone’s head, including those of the lionesses, swivel in the direction of the roar.

Almost simultaneously a white bakkie, a mini-pickup, bounces into view near the lionesses and stops there. The woman driver surveys the two lions with binoculars and writes something in a notebook. Bored with it all, they lie back down.

Momentarily distracted from the fact that there are lions to the left and lions to the right, we ask Syd, “Who’s that?” Against all training, we have condensed into a tight ball behind him. Even Bernardo has moved up.

Syd still stares in the direction of the roar. “The ecologist,” he says, “she works in the reserve.”

The bakkie leaves the lions and rattles over the rough ground to where we are.

“Morning,” the ecologist nods to each one of us in slow motion. I wonder to myself if the lion that roared is moving in our direction.

She looks at Syd. “There’s a male about a quarter mile up the road. Be careful where you walk.”

Is it?” he says, “thanks.” Their exchange is so matter-of-fact that it sounds as if they’re discussing potholes.

“Right then,” she says and the bakkie joggles off. Not even an offer of a lift.

Bernardo and Syd have a short conversation in Shangaan. Then Syd says, “We go back the same as we came. Bernardo goes to get the Rover.”

Bernardo leads and Syd provides the rearguard. As soon as we move, the lionesses’ heads pop up again and follow our exit. We move as one, marching in step, our spines expectant of fang and claw. Once we’re out of view behind clusters of brush, Bernardo trots off, and I am now in the lead, careful to back track our own footprints.

Soon we’re in the Rover headed again to the clearing. The male has not roared again. One of the lionesses opens her eye as we drive up, then shuts it again and flattens her ears. We are an annoyance to her afternoon nap but nothing to get excited about; not like whatever that strange beast was that just left.

Syd tells us that these sisters are the only survivors of a pride that once ruled this territory. Another pride recently moved in and killed their relatives. That was the reason they did not answer the male lion. We were lucky one more time: if they had answered, he would have come running.

One of the sisters has recently been in a fight. She has a wound on her shoulder and has not eaten while healing. Her ribs are showing.

“They do not bring food to each other,” Syd says. “She has to be well enough to hunt.”

We watch the sisters as they nap. We have evolved from being possible prey to compassionate observers, all because we’re sitting in our trusty Rover.

“Will they make it?” one of us asks.

“Do you feel sorry for them?” someone else adds.

“Yes,” Sid says, “yes. But that is just my feeling. If they move to another territory, they will be okay.”

photograph by Cheryl Merrill

photograph by Cheryl Merrill

The lionesses nap side-by-side. Without opening her eyes the healthy one raises a front leg and drapes it over her sister’s neck.

Driving back to camp at dusk, we find a male lion awakening from an afternoon nap. According to Syd this lion is very young, trying to move into a new territory, and challenge the two males who recently took over. He has a black punkish stripe in his still-growing mane and no scratches on his nose. He’s not far from where we found the sisters and might be the lion who roared. He blinks at us sleepily, then looks off into the distance, his yellow eyes still not completely open.

photograph by Cheryl Merrill

photograph by Cheryl Merrill

As it gets darker we find the eyes of bushbabies reflecting our spotlight like bright Christmas ornaments in the trees. They are distant cousins of ours, using their quick hands and enormous eyes to forage for fruit, insects and bird eggs at night. Long shaggy tails provide balance as they leap from branch to branch, dodging the quick flicks of light we direct at them. We catch glimpses without blinding them.

Syd stops the Rover by a bush. “See him?” Our heads swivel in all directions. I don’t see anything but bush.

Illuminated by the headlamps on the Rover, Syd climbs out and walks over to a round-leafed teak. He reaches up and suddenly a Flap-necked chameleon comes into focus right by his hand. It is a perfect mimic of the leaves on the teak.

We shake our heads and smile at each other.

Back at camp we’re presented with our certificates of completion for our short three-day course.

“Don’t worry about your job, Syd,” we tell him, “none of us will ever be as good as you are.”

He smiles quickly behind his hand, then kicks at the wood in the fire. “Did I tell you about the leopard that jumped into the Rover last year……….”

 

Here’s a Little Fairy Tale

photograph by Cheryl Merrill

photograph by Cheryl Merrill

 

Here’s a little fairy tale: Once upon a time, elephants lived to a rhythm of their own making. There were no elephants in captivity. They were captured only in legend, in song, painted onto walls of caves, etched on the flat sides of rocks. There were no elephants on reservations, in circuses, in sanctuaries, or zoos. No elephants were murdered solely for their tusks. They were not orphaned by the slaughter of their families, nor made to endure solitary confinement, leg irons, beatings, prods, and electric shocks. They were not enslaved. They were not used as vehicles of war. They were not made to wear radio collars, jeweled headpieces, or bear intricately carved wooden howdahs on their backs. They did not carry princes, or hunters, or loggers, or performers, or tourists. They were not forcibly relocated from the land of their birth. Most died of old age. Once upon a time elephants knew a landscape without fear, without fences, a landscape empty of humans. Once upon a time, elephants were everywhere.

Baobabs, Part Three, Symbiosis

photograph by Cheryl Merrill

photograph by Cheryl Merrill

Found mostly in seasonally arid areas, baobabs grow very slowly as they age, except for first years of its life, when a baobab grows relatively quickly.  A tree planted in Kruger National Park in South Africa grew 65 feet tall with an eleven-foot diameter in just 38 years.  In contrast, an older tree described by Livingstone in 1858 grew only two feet in circumference in 110 years.  Despite their early exuberance, baobabs can be cultivated as bonsai trees.

Young baobabs have only single leaves per stem. Without their crooked branches and five-leafed stems, they are difficult to recognize. Kalahari Bushmen believe the trees appear fully-grown, planted upside down by the gods, with the tree’s roots in the air. They also believe spirits inhabit the baobab’s large, waxy-white flowers, and if anyone has the audacity to pick one, they will be eaten by a lion. The flowers open just before dark, produce copious amounts of nectar and last for only 24 hours. Their heavy, carrion-like scent attracts nocturnal insects and bats, such as the Epaulleted fruit bat. The Kalahari Bushmen are right: the smell of a freshly-picked baobab flower behind your ear would make you bait for lions drawn to the carrion scent.

Older baobabs have a tendency to rot out their heartwood, but completely heal around the hollowed trunk. Rats and reptiles frequently invade them and African honeybees often establish hives in crevices of a baobab. Native to central and southern Africa the bees are actually a subspecies of the Western honeybee. A single sting from an African bee is no more venomous than a single European or American bee sting, but African honeybees respond more quickly when disturbed and send out three to four times as many workers in response to a threat. They also pursue an intruder for a greater distance from the hive – thus their reputation as “killer” bees.”

Physically unable to break open a beehive, the Honeyguide has developed a symbiotic relationship with humans, letting another species take the risk of being swarmed. A Honeyguide indicates the presence of a hive by continuously dive-bombing nearby, all the while uttering monotonous, squirrel-like chirps. Alerted by the Honeyguide, intrepid Kalahari Bushmen pound pegs into the soft bark of baobabs to climb the tree, lull the bees with smoke and obtain a sweet reward for taking that risk. Bushmen always leave honey for the birds, for if they should fail to do so, the Honeyguide will one day lead them to a lion, instead of a hive.

“Pachycaul” is a scientific term used to describe a variety of thick-stemmed plants with few branches. “Pachy” is Greek for “large” and “caul” is Latin for “trunk.” Pachyderm is a term for describing large, thick-skinned animals such as elephants. In times of drought, elephants strip the bark of the baobab and eat the spongy wood underneath, estimated to contain 40-70% water – which classifies the baobab as the world’s largest succulent. An individual baobab can store up to 32,000 gallons of water.  When pachyderms meet pachycauls, it is the baobab that suffers. Sometimes, during these times of drought, elephants will completely gird a tree, leaving it standing as if on its own pedestal, and yet the baobab will still survive.

Weighted with water, baobabs barely move in the wind. Even a mild frost will kill a baobab, so they are never found at elevations over 3,000 feet. The tree is also sensitive to both flood and extended periods of drought. In Madagascar, a sugar mill diverted water onto land containing baobabs, which subsequently stood in water year-round. The trees began to rot and topple over until the land was drained and the remaining 313 baobabs upon it were declared part of a conservancy area.   A highway constructed near the Nomslang Baobab in South Africa brought thousands of visitors to marvel at its size. Unfortunately, their feet trampled the earth beneath it into hardpan, making the ground impervious to rainwater and the famous baobab died. Baobabs melt into a huge, fibrous mass within a few months after their death, leaving behind mounds of stinking pulp and a pit filled with a rotting taproot. Soft spots around dead baobabs also indicate locations of its root system, which may radiate just below the surface for 300 to 1300 feet.

Some species of plants and trees emit chemical signals when under attack. I wonder if the baobab talks to its long-lived kin as it dies. Baobabs live up to two thousand years, 730,000 revolutions of daylight and darkness. Perhaps its chemical whisper is Patience, perhaps it is Eternity, perhaps it is Dream.

 

 

The most comprehensive book ever written about baobabs is The Baobabs: Pachycauls of Africa, Madagascar & Australia, Gerald Wilkins and Pat Lowe

 

Baobabs, Part Two, Utility

photograph by Cheryl  Merrill

photograph by Cheryl Merrill

 

In 1998, the Disney Corporation opened the Animal Kingdom Park in Florida. It is, in essence, a 500-acre zoo, containing 1,700 animals representing 250 species, from Abdim’s storks to African zebras. In the center of the park is a 145-foot-tall, 50-foot-wide sculpture of a baobab, representing the Tree of Life from the Disney film, The Lion King. Much larger than any known baobab, the sculpture is molded around a refitted oil platform. Its trunk is carved with 325 animals and contains a theater with 430 seats. Fixed to its branches are 103,000 leaves dyed five shades of green, made of kynar, a flexible fluoropolymer resin.

Eight species of living baobabs exist: six in the dry deciduous forests of Madagascar, one in Australia and one which grows in West, East and Southern Africa. Baobabs on the Arabian Peninsula are the result of human settlements. All baobabs are deciduous. Nude limbs, entangled as a root system, seem to search for moisture from the sky. Kalahari Bushmen believe the trees appear fully-grown, planted upside down by the gods, with the tree’s roots in the air. They also believe spirits inhabit the baobab’s large, waxy-white flowers, and if anyone has the audacity to pick one, they will be eaten by a lion.

Hollow baobabs have a long history of creative uses by humans. During World War II, a baobab in Namibia was fitted with a toilet. The toilet is still there, but the tree has grown around the door, which no longer opens. On the lower Zambezi River, the Kayila Lodge has an operational toilet tree, used more for photo opportunities than necessity. And on a private farm in Sunland, South Africa, an enormous baobab contains a wine cellar and bar, complete with draft beer, a dartboard, stools, and a wooden bench along the wall. This tree is possibly the oldest baobab in existence – it has been radiocarbon-dated to the end of the Stone Age, around six thousand years ago.

In Kasane, Botswana, a baobab was used as women’s prison in the early twentieth century. Incarceration with potential rat and reptile cellmates might make any criminal think twice. Although that baobab died in 1967, an offshoot now grows next to the remains of the jail. Throughout Africa, hollow baobabs have served various purposes – as hiding places during tribal warfare, as shops, storage shelters, barns, chapels, burial sites, post offices, even a bus stop.

Almost every part of the baobab is edible. Fresh leaves are eaten as spinach and condiments. The shoots from germinating seeds taste like asparagus. Bulbs from its roots make porridge. Fluid extracted from the bark of the baobab is used to dilute milk. The ash from a burnt tree is a good substitute for salt. Pulp and seeds of its fruit contain potassium acid tartrate as well as citric acid, an effective substitute for cream of tartar, and resulting in the Afrikaans name “Kremetartboom.” Early settlers also used fruit pulp in place of yeast and added baobab leaves to speed up the fermentation process in winemaking. The fruit pulp has the highest known concentration of Vitamin C. It makes a slightly acidic, but refreshing drink when mixed with water. Baobab seeds have the same protein value as domestic nuts and can also be roasted and ground into a substitute for coffee.

The baobab is often called “the Monkey-bread tree,” because baboons and monkeys eagerly consume its fruits. Nearly all four-legged browsers eat the baobab’s fallen leaves and flowers. The flowers open just before dark, produce copious amounts of nectar and last for only 24 hours. Their heavy, carrion-like scent attracts nocturnal insects and bats, such as Peter’s Epaulleted Fruit Bat. In times of drought, elephants strip the bark of the baobab and eat the spongy wood underneath, estimated to contain 40-70% water – classifying the baobab as the world’s largest succulent. An individual baobab can store up to 32,000 gallons of water and weigh 266,880 pounds – or one hundred and twenty-one tons.   A bull elephant weighs up to 16,000 pounds or seven tons. If you stacked elephants one upon the other, it would take seventeen or eighteen elephants to equal the weight (if not the mass) of the water stored in a large baobab.

The name baobab derives from North African Arabic, bu-hibab, “fruit of many seeds.” Within life spans that reach six thousand years, the baobab nourishes countless species, takes in tons of carbon dioxide and releases equal amounts of oxygen. Used and re-used, a baobab cycles and recycles, measures seasons by dropping its leaves, measures centuries by the blur of life beneath its limbs, unaware of that strange human notion of time.

 

Islands in the Okavango Delta

photograph by Cheryl Merrill

photograph by Cheryl Merrill

 

Swollen by November rains, the Okavango River floods south from Angola, arrives in Botswana in May or June, fans out, and then stops when it bumps into a barrier of fault lines near Maun. Landlocked, the river penetrates deep into the Kalahari Desert before it dies in the sand. Not a single drop reaches the sea.

As the river pushes south, it creates an oasis, a floodplain the size of Massachusetts, containing an ark-full of animals: the Okavango Delta, a flat maze of islands and water.

The river descends less than 200 feet in 300 miles. Bracketed by fault lines, sediments deposit elevation changes of less than seven feet. Islands that rise above the floodplains tend to be long and sinuous, following old channel routes, linking to other uplifted channels, and creating large dry fingers of land that will be outlined by next season’s floods. Water loving trees such as the Jackalberry, Mangosteen, Knobthorn and Sycamore Fig fringe these larger islands.

The Delta contains more than 50,000 islands; their landmass roughly equals that of water. Paths cross some of the islands; roads cross others; water surrounds the rest. All of the islands carry the mixed vegetation of the Kalahari sand plains. Approached by foot in this maze, every island looks like the next one and the next one and the next, especially during the low flood season, when boundaries between them evaporate with the water, when footpaths end in walls of thick bush, and roads take every opportunity to wander off in a new direction.

Sometimes you’ll wade to an island; sometimes the water is over your head. Near the southern end of the Delta, some of the islands are larger sandveldt tongues, extensive areas of the Kalahari that penetrate deep into the flood. In the Okavango’s vast delta of uncounted islands, a few inches here or a few inches there separate wet lagoons from dry land. If I turn one way, I’m lost in a maze of floodplain islands, now high and dry. Turn the other, and I’ve entered into a maze of Kalahari woodland. Until I’ve gone a few miles, it’s hard to tell the difference since the same vegetation covers both.

But when the sun sets, magic begins. The sky turns pink; water lilies fold into perfect imitations of floating candles; papyrus along shorelines become golden sentries; and the spell of water over a desert casts its memories into your dreams.

Why Don’t Elephants Get Cancer?

 

photograph by Cheryl Merrill

photograph by Cheryl Merrill

 

This collared elephant, photographed in Botswana’s Chobe National Park, has a large breast mass – most likely mastitis, an inflammation or abscess of breast tissue often caused by blocked milk ducts. Although harmful bacteria may be present in her milk, nursing might relieve her mastitis symptoms. I don’t know the outcome for this mother, but it’s highly unlikely her breast mass was cancer related. Why? For elephants, the overall lifetime chance of dying from cancer is less than 5%. The mortality rate for humans is 20%.

Why should a mammal with 100 times more cells than we do have such a low cancer rate? Oddly enough, there is little relationship between cancer rates and body size of mammals – even though the cells of elephants will divide many more times throughout their lifetimes than ours will, simply because they have so many more of them. Elephants ought to have a greater quantity of random mutations predisposing them to cancer than we do.  But they don’t.

Studies using the autopsy reports of 36 mammals at the San Diego Zoo (ranging in size from mice to elephants) and the database of 644 captive Asian and African elephants confirmed that the relationship of cancer to body size did not matter. But those studies also found something highly unusual in the blood cells of elephants. African elephants have twenty TP53 genes (and therefore 40 alleles of that gene); Asian elephants have fifteen. TP53 is sometimes called the “guardian of the genome” for its ability to create a protein that suppresses tumors.

Humans have just one gene and two alleles of TP53. (An allele is basically a copy of a specific gene at the same position on a chromosome.   Chromosomes are located in the nucleus of cell and contain DNA, the genetic instructions that make mice mice and elephants elephants.) In humans, one allele is inherited from each parent – both crucial to prevent cancer. Having only one allele causes Li-Fraumeni syndrome, which is characterized by a more than 90% lifetime risk of cancer.

TP53 codes for the protein p53, a crucial tumor suppressor that stops cells with damaged DNA from dividing. TP53 goes into action when cells suffer DNA damage, churning out copies of its associated p53 protein and either repairing the damage or killing off the cell. But instead of repairing DNA damage, compromised elephant cells have evolved to always commit suicide rather than pass on potentially harmful mutations acquired in trying to repair itself. Once the damaged cell is dead and gone, it can’t turn into cancer.

Most of the elephant TP53 genes are retrogenes, which evolved into their genome at a later time than the original gene. Two factors explain why elephants developed more TP53 genes: a long gestation period (22 months) and a reproductive lifespan that lasts well into their 50s (elephants live 60+ years in the wild). Unlike mice, elephants don’t reproduce often – thus they pass along the extra copies of TP53 even in old age, and their progeny benefit.

In contrast, humans reproduce only into to middle age and most of our cancers are diseases of aging. We are the legacy of short-lived ancestors (compared to modern life expectations), who mostly didn’t get cancer throughout their years of reproduction and raising children. As modern humans age, our chances of contracting cancer become greater since we have less suppressing genes than elephants do. And any cancer-fighting mutations within our genes don’t get passed along in our older years.

Do elephant genes hold the secret of a cure for cancer? Researchers are investigating. Meanwhile, elephants are being slaughtered for their ivory, for short-term gains. What if elephants were our saviors, our partners in longer, healthier lives? What if elephants were worth much more alive than dead? #worthmorealive Spread the word.

 

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