When it finally arrived, I was more than a little disappointed. Some time earlier, I had bought some of Elvis Presley’s hair on eBay and, like a child waiting for Christmas, had then had to endure weeks of over-excitement and speculation while I waited for my purchase to turn up. I was expecting something as iconic as the King himself. The package, I told myself, would at the very least be made of gold lamé and studded in rhinestones. It would arrive with great ceremony, serenaded by its own backing band, willed on by the frenzied screams of female fans who would camp outside my house and faint when the parcel arrived. But when the postman finally delivered my precious cargo, it was without fanfare. He didn’t even ring the bell. He just popped the plain brown envelope through the letterbox and walked away.
I picked up the drab, un-Elvis-y anticlimax and turned it over in my hands. Save for the Memphis postmark smudged across the top right-hand corner, there was little hint as to the import’s legendary contents. Perhaps things would be more promising on the inside, I told myself. Brimming with nervous energy – all shook up, even – I carefully opened the envelope and teased out the contents. But the luxuriant quiff of my dreams was nowhere to be seen. Instead, I found myself staring at an A4-sized ‘Certificate of Authenticity’. ‘You are now the proud owner of a genuine strand of Elvis Presley’s hair,’ the certificate crowed. But where was the hair? Perhaps they had forgotten to include it, or maybe it was being sent separately under armed guard from Graceland. I scoured the shoddily photocopied piece of paper for a clue. And it was only then, under the full scrutiny of my most intense Paddington Bear stare that I noticed a blob of dried glue at the bottom of the page. It was pea-sized and transparent, easy to miss, but inside it, like an insect trapped in amber, was a short strand of hair. I stared at it, unable to believe what my eyes were seeing, incapable of processing what I held in my hands. Words actually failed me. Not only was the ‘strand’ minuscule – smaller, even, than a single eyelash from my face – it was also … I can’t bring myself to say it … ginger. Elvis Presley, if the certificate was to be believed, was strawberry blonde.
As the penny dropped I felt so lonesome I could cry. I had spent $14.90 (plus postage and packing) and endured a longer wait than the King’s fans had for his comeback tour, only to receive what appeared to be Ronald McDonald’s nasal clippings. So I did the only thing I could think of. I sealed the certificate back up in its original envelope, found a thick black marker pen and wrote upon it, ‘RETURN TO SENDER’, adding that the address was unknown. The irony, I was sure, would be lost on them, but it put a smile back on my face. Then bright and early next morning, I sent my letter back.
I’m not sure, to this day, exactly why I decided to buy a strand of Elvis Presley’s hair. It’s true, I’ve been a fan most of my life. I have an Elvis clock in my study, an Elvis jumpsuit in my wardrobe and a be-quiffed hamster that sings ‘Rock-a-hula’. When I got married, my lovely mum walked me down the aisle to the sounds of ‘Burning Love’.1 But I’m not obsessed. I just like his music and the kitsch paraphernalia that goes with it. So when I stumbled across a strand of his hair during my daily trawl of Elvis eBay ephemera, I simply had to have it. Hair, I knew, is an excellent source of DNA, so the purchase offered the chance to buy a piece of genetic history, the very DNA that helped to shape one of the most talented and beautiful men on the planet. I bought a strand of Presley’s hair because it seemed the ultimate Elvis trinket. I bought it out of academic curiosity. I bought it because it got me thinking …
… if you could retrieve Presley’s genome from a lock of hair or some other source, could you somehow use it to bring back the King? Could you ‘de-extinct’ Elvis Presley? And if you did, how similar or different would the new Elvis be from the original? Did Elvis have sexy DNA? Was there some part of his genome that endowed him with his famous pouty sneer or extraordinarily agile hips? How about his predilection for fried peanut butter and banana sandwiches, or his penchant for blue suede shoes? Would we bring him back only to condemn him to a second untimely toilet-related death?
Now, at this point, there will, I’m sure, be those among you wanting to gnaw off their own legs in agitation. ‘There’s no point cloning pop stars,’ I hear you cry. ‘Simon Cowell has been doing that for years and they’re all rubbish … And besides, Elvis is dead, not extinct, so you can’t talk about de-extincting him … OK?’ To which I reply, fair point about Simon Cowell. However, human beings may not be extinct … yet. But our time, inevitably, will come to pass. So when, not if, we become extinct, will we leave behind the instruction manual and the technology for de-extincting ourselves? People, myself included, have mused on the possibility of de-extincting ancient humans, but few have dared to draw the thought experiment to its logical conclusion: whether or not we ourselves could be de-extincted. We’d be wise, at least, to think about it. And if we are going to think about it, we might as well make our test subject easy on the eye … and on the ear. A discussion about de-extincting Homo sapiens is not foolish. It’s prescient. And to anyone who finds themselves shouting, ‘Sexy DNA? Are you mad, woman? There’s no such thing as “sexy DNA”. The phenotype of any human being is a complex interaction of genetic, epigenetic, environmental, not to mention stochastic factors,’ I say, calm down, a little less conversation. I’ll get to all that. But for now, let’s rock ’n’ roll.
In the Ghetto
Elvis Aaron Presley – the real deal – was born around noon on 8 January 1935, in Tupelo, Mississippi. His mother, Gladys Smith Presley, a poor cotton picker, gave birth to twins. But Elvis’s brother, Jesse Garon, was stillborn. Elvis’s father, Vernon Elvis Presley, drifted from job to job and spent time in jail, and Elvis grew up an only child in the family’s modest two-room wooden shack. He had a very musical childhood. In the evening, he would sit on the porch with his family and sing. At church, he would squirm out of his mother’s arms so he could join in with the choir. He listened to Pentecostal church music, musicians singing the blues and the Grand Ole Opry, a weekly country-music concert that was broadcast on the radio. Then, aged 10 or 11, his mum took him to the local hardware store and bought him his first guitar.
In 1948 the family moved to Memphis, Tennessee, where Elvis restyled his hair into a ducktail-do to hide his teenage acne. He heard jazz in the legendary Beale Street, and then one day, the story goes, he drove past a sign that changed his life. It was an advert for the Memphis Recording Service, a ‘make your own’ record set-up charging four dollars for two songs. Elvis decided to record a couple for his mum, but the studio’s owner, Sam Philips, was so impressed by his vocal range that he signed Presley up to his record label, Sun Records. In 1954, Elvis released his first single, ‘That’s All Right’. According to Rolling Stone magazine it was the first rock ’n’ roll record ever made. A year later, fans rioted outside his concert in Jacksonville, Florida, when Elvis finished his show by cheekily announcing, ‘Girls, I’ll see you backstage.’
At 19 years old, Elvis was already well on his way to becoming an international sensation. With a sound and style like nothing before, a dangerously mobile pelvis and an electrifying stage presence, Elvis ushered in a new era of US music and popular culture. His gyrating hips were deemed so sexy that certain TV programmes refused to broadcast the bottom half of his body. Then in 1956, with a new record deal under his belt, he released ‘Heartbreak Hotel’. It was the first record to simultaneously reach number one in three different charts: the Billboard Country and Western chart, the Rhythm and Blues chart and the Pop chart. After that, the movies beckoned. Elvis released a string of 33 films and moved into the ultimate man cave, Graceland. By the time he was drafted into the US Army he had released 14 consecutive million-selling records. In 1967 he married Priscilla, and a year later returned to TV with his electrifying, sultry comeback special called simply Elvis. Black leather has never looked so good.
In the years that followed, he experienced some of his highest and lowest moments. He released ‘In the Ghetto’ and ‘Suspicious Minds’, but his health was starting to fail. The pounds were piling on and Elvis became addicted to prescription drugs. In 1973, amidst his busiest touring schedule ever, he divorced from Priscilla and overdosed twice on barbiturates. He suffered from migraines and glaucoma, slurred his way through his performances, and towards the end of his life had to be physically guided off stage by his minders. In the first eight months of 1977, he was prescribed more than 10,000 doses of sedatives, amphetamines and narcotics. Then, on 17 August 1977, his girlfriend Ginger Alden found him dead on the bathroom floor of Graceland. He was just 42 years old. President Jimmy Carter issued a statement crediting Elvis with having ‘permanently changed the face of American popular culture.’ Muhammad Ali called him the ‘sweetest, most humble and nicest man you’d want to know’ … but could we ever bring him back?
Americans for Cloning Elvis
Once upon a time, in the mid-to-late nineties, when mobile phones weren’t smart and the internet had more hand-drawn porn than crap cat pictures, there was a website called ‘Americans for Cloning Elvis’.2 Inspired by the birth of Dolly the sheep, it featured a grainy image of Elvis gyrating his hips awkwardly as if locked in some eternal digital spasm. The title, ‘Americans for Cloning Elvis’, was written in a retro, pixelated font, and underneath it was a call to arms. The website implored like-minded Elvis fans to sign a petition asking scientists to bring the rock legend back to life. It read:
We the undersigned, in our enduring love for Elvis, implore all those involved in cloning to hear our plea … The technology is here, and this petition is a testament to our will.
There are Americans, it seems, who would genuinely like to see Elvis cloned; either that or they’ve too much time on their hands and like signing petitions. Today, the website is still live and largely unchanged, and more than 3,000 people have added their name to the cause. How serious they are is up for grabs. They don’t, I’m fairly certain, hang out in secret laboratories practising nuclear transfer on embryos with quiffs, but they have at least thought about cloning the King. But what would it take? Where to start?
The plan would involve finding a source of Elvis’s DNA, decoding his genome then editing the parts of it that were unique to him into a regular human cell. The DNA-containing nucleus of this cell could then be used for cloning to create a baby that would effectively be Presley’s identical twin. At face value it’s not so different to the method being used by George Church to make a hairy elephant, but this is Elvis we’re talking about. Where mammoth DNA can be found with relative ease in the cells of thawing Arctic carcasses, there was only ever one Elvis Presley, and he’s currently pushing up the daisies at Graceland.
But you can, as my own experience has shown, buy snippets of famous people’s hair on the internet and through private dealers.3 A few clicks on Google turn up locks belonging to the likes of Princess Diana, Abraham Lincoln and Michael Jackson.4 Just as authenticity varies, so does price. Although I may have parted with the best part of $15 for something that looked suspiciously like a ginger pubic hair, a genuine tuft of Che Guevara’s hair is reported to have sold for $119,500. And when Britney Spears had her head shaved in 2007, her hairdresser tried to auction the locks online with a starting price of $1 million.5
But if you want to find anything to do with Elvis, there’s really only one place to go: the Loudermilk Boarding House Museum in Cornelia, Habersham County, Georgia. From the outside it looks unassuming, a pretty timber-built structure with twin gables and a big white veranda. But on the inside is the quirkiest, craziest collection of Elvis memorabilia that there is, comprising Joni Mabe’s ‘Travelling Panoramic Encyclopaedia of Everything Elvis’. Mabe, a talented artist and self-proclaimed ‘Queen of the King’, has been hoarding Elvis knick-knacks ever since the day the King ‘left the building’. She has five rooms of glitzy collectables stacked from sequinned floor to satin ceiling. Her collection, which toured the world for 14 years, is a haven for the kitsch and the retro. Aside from the more obvious costumes, tabloid clippings and bubble-gum cards, there are Presley prayer rugs, shoestrings and toenail clippers. There’s even the toe tag that Elvis wore as he lay in his Memphis funeral home.
Amidst it all, however, are three possible sources of Elvis DNA.
The first is not just a strand, but an entire lock of Presley’s hair. Dyed black in alleged homage to fifties movie star Tony Curtis, Presley’s pomade-laden quiff required some serious maintenance at the hands of his personal barber Homer Gilland, who squirrelled away and then sold much of the discarded hair. Mabe bought her sample from him directly, so is convinced of its authenticity.
Although the hair on our heads is dead, the hair cells at the base of each strand are very much alive. These divide to generate new hair cells, which then migrate into the hair shaft and become infilled with keratin, the structural protein that makes hair hard. As the cells become keratinised, their DNA starts to break down, but fragments can sometimes still be retrieved many thousands of years later. Mitochondrial DNA has been recovered from the fur of woolly rhinos and mammoths and, in 2010, scientists recovered the full nuclear genome of a 4,500-year-old mummified Inuit … all from his hair. It’s reasonable therefore to assume that genuine Elvis hair, just decades old, could be a source of his DNA. Nor should Presley’s proclivity for hair dye be a problem. When researchers extract DNA from hair they bleach it first then rinse it with alcohol. The step is not cosmetic; rather, it removes any contaminating DNA present on the outside of the strand. In Presley’s case, this means that any DNA recovered would come from the man himself, and not his hairdresser or anyone else.
A second potential source of DNA comes from another keratinised structure, this time one that Mabe collected herself when she visited Graceland in 1983. Passing through the dimly lit Jungle Room, Presley’s green-carpeted ‘man cave’ of a den, Mabe became overwhelmed with the urge to literally feel what Elvis had felt. As her tour group moved on, she lingered behind to skim her fingers across the shag pile, only to feel them catch on what she thought was a wayward sequin. It was only when she examined her treasure outside in the broad daylight, that she realised she had found a toenail clipping. ‘It’s either from a second toe, or it’s a piece of the big toenail,’ she says. The sign of a true Elvis obsessive, Mabe has kept the toenail for more than 30 years. Just like hair, nails are also a good source of DNA, but the problem here, is that no one can be sure who the toenail belonged to. A lot of people partied in the Jungle Room, and even more have passed through it since Elvis shuffled off this mortal coil. ‘I call it the Maybe Elvis toenail,’ she says, in her glorious Southern drawl, ‘because maybe it’s from Elvis, and maybe it isn’t.’ Maybe the toenail is from Elvis, but maybe it’s from the guy who laid the carpet. If we’re talking about bringing back the King, ‘maybe’ isn’t good enough, which leaves option three.
Study photographs of Elvis pre-1958, and you’ll notice he has a wart on the back of his right wrist. Subsequent pictures clearly show the dark blob has gone. It was removed by Presley’s personal doctor, who then popped it into a test tube of formaldehyde and kept it for three decades until Mabe bought it from him for an undisclosed amount. The wart now has pride of place in Mabe’s museum, where it remains one of her most popular exhibits. She even sells T-shirts with the logo ‘The King is Gone but the Wart Lives On’. The wart is still in its original container, but the tube is now propped up on a bed of red silk in an old cigar box. ‘It’s as big as a black-eyed pea, but it’s real pus-y,’ says Mabe who seems to relish telling me the gory details. But could Elvis be de-extincted from it?
DNA can readily be retrieved from formaldehyde-preserved tissue but warts don’t make for the best starting material. Put aside for one moment the ‘yuk’ factor and the psychological trauma of finding you’ve been created from an unsightly blemish, there are other problems too.
Warts occur when a skin cell becomes infected with the human papilloma virus (HPV). Inside the cell, the viral DNA hijacks the host’s DNA, making copies of itself that can then invade and infect neighbouring cells. Infected cells divide more rapidly than non-infected cells, causing the wart to grow. Sometimes this abnormal growth gets out of hand, and an originally benign wart can become cancerous. It’s for this reason that Presley would have had his wart removed.
Were someone to extract the DNA from an HPV-infected cell they’d find a mix of human and viral genetic material. The human genome, at three billion base pairs, dwarfs the HPV genome, which consists of a runty 8,000. But size, as Napoleon undoubtedly said to Josephine, isn’t everything. It’s what that tiny genome could do that would be troublesome. If the Elvis/virus DNA mix was inserted into an empty egg and used for cloning, then every cell in the developing embryo runs the risk of having both Elvis DNA and virus DNA. Given HPV’s reputation for causing abnormal cell growth and cancer, this could have unpredictable and potentially dangerous consequences. The developing human embryo is a miracle of finely tuned genetic activity. Chucking an extra load of ‘alien’ DNA into the mix would be like throwing a spanner into a car engine. If you’re lucky, nothing much happens. If you’re unlucky, the engine dies. Warts are not a suitable source of DNA for cloning.
So it looks like Elvis’s iconic coiffure, or part of it, is the best place to begin our quest to bring back the King. After the best part of half a century, Presley’s genome would be expected to have broken into millions of shorter fragments, but this shouldn’t be a problem. In 2014, scientists working for the Channel 4 documentary Dead Famous DNA took a sample of Elvis Presley’s hair and managed to extract DNA from it. They didn’t try to decode the entire genome; rather they read the sequence of some of the snippets that they recovered (of which more later). But if they or anyone were to sequence enough fragments enough times, eventually the whole genome could be decoded and reassembled inside a computer. Stored in digital form, it would be the longest recording Presley ever made.
But it wouldn’t be complete. In 2004, researchers announced that they had finished sequencing the human genome. It was, the then-US president Bill Clinton said, ‘the most wondrous map ever produced by human kind.’ One of the most significant scientific milestones of all time, people compared it to the invention of the wheel or the splitting of the atom. The culmination of more than a decade’s work by thousands of scientists across the globe, it promised unparalleled insights into human development and disease, and to pave the way for the development of new therapies. But it wasn’t complete. When they set out to decode the human genome, researchers decided to focus on only the most active, gene-dense regions, the so-called euchromatin, because, they reasoned, these were likely to be the most important bits. The remainder of the genome, a small gene-light fraction of the total DNA known as the heterochromatin, was thought less important. It was also fiendishly tricky to decipher, so researchers decided to leave it well alone. The result: when the human genome sequence was finally ‘finished’ and published in the journal Nature, the heterochromatin was missing, and the sequence they had for the euchromatin was full of holes, around 340 of them. According to one of the partners in the project, the National Human Genome Research Institute, the human genome was as complete as it could be ‘within the limits of today’s technology’. It’s like saying my family holiday to France was complete when we got to Dover and missed the ferry – the technology required to get us across the Channel was simply not there at the time.
Since then, DNA sequencing has improved. Its cost has dropped and the technology itself has become widely available. But even the most thoroughly sequenced genomes are still incomplete. Although researchers have made inroads into sequencing the difficult-to-read heterochromatin, the best-sequenced human genomes are still only around 95 per cent complete. The problem is that parts of the genome are full of repetitive, stuttering snippets of code. Imagine buying a thousand copies of Richard Dawkins’s The God Delusion,6 then putting them through a shredder7 and trying to reassemble them. The word ‘God’ will be repeated many times, but it’s hard to know which ‘God’ went where. Just like the human genome, it’s hard to reassemble these tricky bits into the correct order.
Also, there are mistakes. We’re only human after all. The official human genome sequence had an overall error rate of less than one error per 100,000 base pairs. That means that, although around 2,999,970,000 letters of the code are correct, 30,000 or so of them will be wrong. It’s for this reason that geneticists like to check and double check their sequencing data. They call it ‘coverage’. If a genome has 30x coverage – pretty much the best that there is – it means that most parts of the genome will have been double checked 30 times or more. But other parts of the genome will have been checked fewer times than this, and some regions will not have been read at all. A completely complete human genome, it seems, is wishful thinking.
If we were trying to clone a generic human, then these inconsistencies and omissions would probably count for little; most single letter changes to the genome have no effect, and gaps in one genome could be filled in with appropriate sequences from another. But because we’re trying to clone a specific human it becomes a potential problem. The plan, remember, is to sequence Presley’s genome then edit the parts of it that were unique to him into a regular human cell. But if these unique Elvis sequences lie in parts of the genome that either can’t be read or have been read incorrectly, we run the risk of missing them altogether.
Essence d’Elvis
That Elvis was one of a kind is a claim without doubt, but his DNA was reassuringly mundane. Scientists have sequenced bits of celebrity genomes, including DNA sequences from Charles Darwin, Isaac Newton and Elvis Presley, and found them to be made of the same four chemical letters – A, C, G and T – that make up all our genomes. They are not bigger, studded with stars or decorated with dollar bills. But they are all unique.
In 2012, researchers announced that they had sequenced and compared the genomes of 1,092 different people from around the globe. These weren’t celebrities, just everyday people, and the goal of the study, called the ‘1000 Genomes Project’, was to understand what makes people’s genomes different. What they found is if you compare any one person’s genome with that of a non-relative, there are around three million differences, or ‘variants’. That means there are around three million genetic differences between you and me, between me and Elvis, and between Elvis Presley and any non-related person on the planet. Our genetic sequences differ at about one place in every 1,000 or so letters. Most of the differences are small. An A may be substituted for a T. Perhaps a G is left out somewhere. Maybe there’s an extra C hiding away somewhere else. If the human genome were a book, then everybody’s book would contain the same chapters, paragraphs, sentences and words, arranged pretty much in the same order. But my book might be missing an apostrophe on page 521,8 while on the next page your book might say the word ‘pants’ instead of ‘parts’. Every now and then, however, bigger changes crop up. Whole paragraphs might be duplicated, and words might be repeated. A person with Down’s syndrome, for example, has an entire extra copy of chromosome 21, while a person with Huntington’s disease, a brutal and incurable neurodegenerative condition, has many extra copies of the sequence ‘CAG’ hiding inside a particular gene.
The differences occur because when regular cells divide – to create new cells, to build body parts, to help injuries heal – they don’t always do it perfectly. In an ideal world, when one cell splits into two, the genome is duplicated then divvied up identically. Each ‘daughter’ cell receives an exact copy of the original ‘parent’ genome. But the copying mechanism isn’t perfect, and mistakes, or ‘mutations’, creep in. When a mutation occurs in a sperm or an egg cell it is passed on to the next generation. The result, your genome, contains about 60 ‘new’ mutations that you inherited from your parents and many older mutations from further back in your family tree.9 In addition, our genome is constantly under assault from DNA-damaging radiation, pollutants, chemicals and the like; and although most of this damage is patched up, we continue to accrue changes to our genetic code with every day we are alive.
With seven billion people on the planet and counting, the individual genetic variants that you carry are unlikely to be unique to you. I may have a ‘C’ instead of a ‘T’ towards the end of chromosome 2, but you might do too. But you won’t have all of the other 2,999,999 genetic variants that make me me. ‘Almost none of your variation is unique to you,’ says geneticist Gilean McVean from the University of Oxford, one of the leaders of the 1000 Genomes Project. ‘What is unique about you is the combination of the variants that you have.’ Hidden somewhere amidst the three million genetic variants lurking in Elvis Presley’s genome is the genetic essence of Elvis, the collective spattering of idiosyncratic nucleotides that helped to make him the person that he was.
In the last few years, geneticists have begun to link combinations of these variants to all sorts of diverse characteristics, such as height, obesity and mathematical ability. The combined action of many, many variants scattered across our genome are now thought to influence everything from the way we grow to the way we behave to the diseases we develop. ‘It’s like a background genetic effect,’ says McVean. ‘It could very subtly influence everything from the shape of your nose to whether or not you like gherkins.’ It’s these tiny differences, these individual foibles and features, that in part help to make us who we are. My personal collection of genetic variants could help explain why my nose looks like a blob of pasty-coloured modelling clay, and why, while I welcome the gherkin, I eschew the cornichon. Even though on their own, the vast majority of Presley’s genetic variants will have had little or no effect, put them altogether and there you have it: the genetic essence of Elvis. ‘The constellation of factors that make up Elvis are a result of many, many weak influences across the genome,’ says McVean.
That means if we want to create a genetic replica of Elvis we can’t skimp on the detail. If there are three million genetic differences between Presley’s genome and that of a mere mortal, then to de-extinct the King, we’re going to have to edit each and every single one of them into a human cell. It’s too big a job for that darling of the gene-editing world, CRISPR, so geneticists would instead have to turn to CRISPR’s big brother, MAGE, which can bulk-edit multiple changes into a genome simultaneously (see Chapter 2). The Presleyfied genome would then be injected into a human egg that had had its own nucleus removed, and that cell would then be coaxed to start dividing in a dish.10 A few days later, a healthy looking embryo would then be transferred into the uterus of a surrogate mother, who would then be advised to stock up on DVD box sets and put her feet up. All going well, nine months later, a healthy baby boy – let’s call him GElvis (short for Genetically engineered Elvis11 ) would be born. But how much like Elvis would he be? To what extent would his carefully crafted DNA influence the way he turned out?
Seeing Double
We know that Elvis was born a twin, and although it’s unknown whether his stillborn brother was identical or non-identical to him, two things are certain. First, twins of any kind are incredibly special. I should know; I have twins of my own. And second, through the scientific study of twins we can glean insight not just into how GElvis might turn out, but how we all end up the way we do.
With identical DNA, or near as damn it, GElvis would effectively be Elvis’s identical twin. And as anyone who has watched The Shining will tell you, identical twins can sometimes be spookily similar. Not only do they look alike, they sometimes share the same mannerisms, interests and habits. For the most part we presume that these similarities are down to the fact that not only do they have the same genes, but they also grow up in the same environment. They have the same parents, live in the same household and attend the same school. Much to my own twins’ disgust, they also share the same bedroom and, more often than not, the same mismatched socks.
But sometimes, identical twins that grow up separately can also end up alike. In 1979, US psychologist Thomas J. Bouchard came across the Jim-twins. Adopted by different families when they were just four months old, the twins grew up unaware of one another’s existence. Then Bouchard reunited them when they were 39 to discover that not only did the two brothers look alike, they shared a whole list of unexpected similarities. Both bit their nails, folded their legs the same way and dangled keys from their belts. Both were married to women called Betty, divorced from women called Linda and had owned a pet dog called Toy. One named his first son James Alan Lewis, the other James Allen Springer. They both drank Miller Lite, smoked Salem cigarettes and holidayed on the same beach in Florida. And to top it all, they both drove the same colour and make of Chevy.
All in all, as part of the now classic Minnesota Study of Twins Reared Apart, Bouchard studied the fates of more than a hundred twins or triplets brought up separately. Overall, the study revealed that an identical twin reared away from his or her co-twin had about an equal chance of being similar to their sibling in terms of personality, interests and attitudes as one who had been reared with their twin sibling. The similarities between the Jims, the study suggested, were down to their genes. Put simply, the environment didn’t seem to make much difference at all. Going by this example, it wouldn’t matter if Elvis and GElvis were born 40 years apart, one into rags in a Tupelo shack, the other into riches in a high-tech hospital; their different environments and upbringings would count for little. Perhaps GElvis would also marry a Priscilla and have his own Lisa Marie. He might live in a big flashy pad in Memphis and even be prepared to fly 1,000 miles for a sandwich.12
But it is, of course, more complicated than that. If the environment didn’t matter then factors such as parenting, education and diet would count for little … which would be nonsense and take away the God-given right of teenagers to blame their parents for everything. When people looked at the Jim twins more closely, they realised that they were actually far more different than was initially assumed. One was a talker, the other a writer. One sported a Beatles-style mop top, the other a Robert de Niro-style do. Much to the probable alarm of one Jim’s second and current wife, his brother had married a third time. The Jim-twins were such a scoop that the media downplayed their differences and instead focused on their ‘spooky’ similarities. Where the men lived, there were loads of guys that drank Miller Lite, smoked Salems and drove Chevys. The Jim-twins habits weren’t eerily similar; most of them were mundanely routine.
So just how different are identical twins? We know that identical twins grow into very different adults. They may look similar but they have their own distinct personalities, and physical idiosyncrasies that become magnified with age. They have different preferences and habits, and often develop different diseases. Just like the rest of us, they are a product of genes and the environment, but what’s up for grabs is the relative importance of each of these factors. To what extent are particular characteristics, such as, say, burger-eating or musical talent, influenced by our genes and how much are they influenced by the environment? It’s a conundrum that scientists have been trying to solve ever since Darwin’s cousin, Francis Galton, first started looking into it over a century ago. They call it the ‘nature versus nurture debate’ and twins are at the heart of it. In the last 50 years, more than 14 million twin pairs have contributed to thousands of studies trying to tease apart the relative roles of DNA and upbringing in everything from personality to piles, gun-ownership to gout.
The rationale is this. Identical twins, formed when a single fertilised egg splits in two, share virtually all of their genes. Non-identical twins, created when separate sperm fertilise separate eggs, share around half. Twins tend to grow up together, so share the same environment. So if a characteristic that you’re interested in, lip-curling, for example, is similar in both types of twin, then genetics can’t play much of a role. The environment is more important. But if identical twins are more similar than non-identical twins at, say, hip-swivelling, then it must be down to their genes. All in all, more than 2,700 twin studies have assessed more than 17,000 different characteristics, and the results are quite remarkable.
It turns out that pretty much whatever feature you decide to look at, the test results of identical twins are more similar than those of non-identical twins. Everything, it seems, has a genetic component. That certain diseases or physical traits tend to run in families comes as no big surprise, but twin studies also reveal that our DNA influences intelligence, obesity and addiction. But the studies go further still. Bizarre though it may seem, twin studies also hint that genetics sways certain life events and lifestyle choices. Your DNA influences whether or not you will fly or flunk at school, marry or divorce, end up a billionaire or go bankrupt. It even plays a role not just in musical ability, but in how much practice you put in.
But just because everything has a genetic component it doesn’t mean that genes control our destiny. Twin studies also reveal that, while almost everything is influenced by our DNA, nothing is 100 per cent determined by it. Whatever characteristic you choose to look at, the environment always plays a role too. Nature and nurture operate in a ‘pushmi-pullyu’ sort of way. Some features are more influenced by genetics, others by the environment.
By studying twins, researchers can estimate the relative influence of genetics versus the environment. They call it heritability: the proportion of observed variation in a particular characteristic that can be attributed to genetic rather than environmental factors. Height and eye colour, for example, are strongly influenced by genetics, as are intelligence and obesity, while addiction, migraine, life events and my own Achilles heel, the hangover, are more influenced by non-genetic factors, like how many tequila shots your ‘best friend’ buys you.
We know that Elvis divorced Priscilla, that he became overweight, suffered from migraines and took too many prescription drugs. But from twin studies we should surmise not that GElvis would end up the same, rather he would be more or less likely to share certain characteristics. From estimates of heritability, we can conclude that GElvis and Elvis (and indeed all identical twins) would be more likely to be similar in terms of appearance and jumpsuit size, and more likely to be different in terms of headaches, drug habits and marital status. But it doesn’t mean that GElvis will become obese or that he won’t divorce. Obesity, for example, may well be one of the strongest genetically influenced characteristics there is, but that doesn’t mean the environment, or, more specifically, the number of burgers in it, doesn’t play an important role too.
Geneticists suspect that this pervasive influence of genetics is caused by the interaction of many genes, which on their own have little effect. Despite what you might have read in the media, there is no ‘gene for’ heart disease or happiness, any more than there is a ‘gene for’ having a quiff or being sexy. With the occasional exception, there are no ‘genes for’ anything specific.13 What there are, however, are our unique three million variants; the bits of your genetic code that make it distinct from mine, that subtly influence whether or not you will develop a particular characteristic or disease. When scientists studied snippets of Presley’s DNA for the documentary Dead Famous DNA they found that he carried a number of these disease-linked variants. Presley’s were related to obesity, migraine and glaucoma, conditions he is known to have suffered from. But it wasn’t, as the show pontificated, the smoking gun explaining Presley’s ill health. Data from the 1000 Genomes Project suggests that we all have around 5,000 or so of these disease-linked variants lurking somewhere in our genome. I have them. You have them. But we don’t all go on to develop the diseases they are linked to. Apart from the odd exception, our genes and genetic variants don’t predestine us to ill health, or anything else for that matter; they just slightly skew the odds that we will turn out one way or another. We are swayed by our genes, not fated by them. Genetics, we can conclude, isn’t destiny. It isn’t even Destiny’s Child.
We realise now that nature and nurture don’t act in isolation. Musically gifted children, for example, are likely to have musically gifted parents who are likely to provide their offspring with both the genes and the upbringing to help musical talent flourish. But there’s more to it than that. Our DNA, it seems, may help shape qualities such as musical aptitude, appreciation and motivation, which in turn may help shape the desire to practise and perform. This in turn may attract praise from a parent, a teacher or a screaming crowd, which in turn may help shape the desire to practise and perform … and so on. Nature and nurture don’t go it alone. They interact with one another. The environment isn’t something that just happens to us. Because of our genes, we may be more likely to search, avoid, flourish or flounder in certain situations. ‘We select environments that are correlated with our genetic propensity,’ says geneticist Robert Plomin from King’s College London. ‘People create their own experiences, in part, for genetic reasons.’ So it wasn’t his DNA that predetermined that life-changing moment in 1953 when Elvis walked into Sun Records to cut his first record, nor was it those long evenings singing on the front porch with his family. Instead, Elvis’s genes and his environment had been dancing an intricate bossa nova for all of his life.
With identical DNA, any variants related to musical ability that Elvis had would also be in GElvis’s genome. By immersing him in music, his parents could help GElvis to play to this innate genetic strength, but it would be no guarantee of rock ’n’ roll stardom. From twin studies we must draw the conclusion not that our DNA dictates our talents, but that we should encourage our children to try different things, find out what they enjoy and what they are good at, and then support them all the way. With a favourable genetic undertow, they will then be more likely to excel. Finding your mojo is about learning to play to your genetic strengths, not flogging a dead genetic nag.
Identical But Different
Armed with an intimate knowledge of his own genome and the variants in it, GElvis might choose to use this unusual heads-up to his advantage. Knowing that he carried variants linked to disease and had a ‘twin’ with health problems, he might decide to do things differently. He might exercise regularly and choose low-fat spread instead of peanut butter. He might ditch the burgers and have a doctor keep an eye on his cholesterol. One thing’s for certain, though; the world that GElvis would grow up in would be very different to 1930s Mississippi. And that would lead to another subtle layer of biological differences that in turn, could influence the way he turned out.
It’s called epigenetics and trust me, it’s a great word to throw into pub banter if you’re looking to impress your friends. Epigenetic changes are those that affect the way genes work without ever altering the sequence of the DNA itself. So identical twins with identical DNA are not the same epigenetically. They may have the same genes but the way those genes are switched on and off is different.
The most commonly studied epigenetic change is one called methylation, where a tiny bundle of atoms called a methyl group attaches to any one of 20 million different locations in the genome and switches genes off. Inexpensive, off-the-shelf ‘chips’ can be used to reveal where the methyl groups land, and in the last few years there has been a surge of studies comparing the methylation patterns of identical twins. Of particular interest are twin pairs where one sibling has a particular characteristic, schizophrenia or cancer for example, and the other one doesn’t, and what tends to be found is that the two siblings have different methylation profiles. It’s jumping the gun to presume that these changes trigger schizophrenia or cancer or any of the other characteristics to which they have been linked. It is, of course, more complicated than that. For most of these disorders, we don’t yet know if the methylation patterns are the cause or a consequence of the disease. But what we do know is that the environment is a big driver of epigenetic variability.
Pesticides, pollutants, alcohol, smoking and diet all influence our epigenetic profile, which in turn affects gene activity, sometimes with lasting effect. The experiences of pregnant mothers, we realise, can shape the epigenomes of their unborn offspring. In one well-studied strain of mouse, the Agouti yellow, subtle changes in the mother’s diet determine whether her offspring will turn out thin with brown fur, or fat with yellow fur. And in another classic animal study, researchers found that the pups of neglectful, inattentive rat mothers ended up with more methylation around key stress-related genes, turning them into skittish, jumpy, stressed-out adults.
People who smoke have different methylation profiles to non-smokers, and although when they kick the habit their profiles return to ‘almost’ normal, certain changes can last for decades. It’s thought these ‘hard to shift’ methylation patterns could help explain why ex-smokers remain at an increased risk of cancer and respiratory problems years after they’ve stubbed out their last cigarette. The experiences of a pregnant mother can influence the epigenome.
Life experiences shape methylation patterns, which in turn influence the activity of our genes, which in turn have the potential to shape our behaviour, lifestyle choices and health. Identical twins, some studies have suggested, start off with similar epigenetic profiles, which then become more different as the years go by and the siblings live increasingly separate lives. But what’s amazing is just how different the epigenomes of identical twins can be at birth. Jeff Craig and Richard Saffery from the Murdoch Childrens Research Institute, Melbourne, have studied identical twins born prematurely and found that their epigenetic profiles are already different at 32 weeks – a full two months before most ‘regular’ babies are born. This is because although the unborn siblings may share the same environment – their mother’s womb – the experiences they encounter inside it are different. One twin might be squashing the other or be closer to the mother’s heartbeat. One twin might have a slightly narrower or longer umbilical cord, skewing the flow of nutrients from mother to child. Although the differences might seem insignificant, Craig believes they have the power to wreak significant change. Talk to the parents of identical twins and they’ll very often tell you how their babies’ personalities were different from day one. Very often identical twins are born different weights. Sometimes they are born with different hair or eye colours, or one twin might be healthy while the other has some sort of medical problem. Early life experiences, linked to epigenetic change, could be responsible for some of these changes. And the effects could be long-lasting, too. Craig suspects that sometimes, the time we spend in our mother’s womb may lay the biological foundation for diseases that we develop decades later.
Transferred not as a twin but as a singleton into the womb of a surrogate mother, the first nine months of GElvis’s life would be unavoidably different to that of his DNA donor. Instead of competing for resources and space like normal twins, GElvis would have his embryonic abode all to himself. And where Presley’s mother lived in poverty in 1930s America, GElvis’s surrogate would enjoy an altogether more contemporary lifestyle, with plentiful food and state of the art medical care, all of which would drive variation in the epigenome of her unborn baby. After birth, as GElvis grew up in this twenty-first-century world of ours, his diet, family, friends and experiences would be unlike those of his famous clone. This would drive further change in his epigenome, and although the exact repercussions are impossible to predict, it’s safe to say that they would conspire to make Elvis and GElvis less alike, rather than more similar. But more than that, Craig and colleagues have found epigenetic differences in cells taken from naturally conceived twins and twins created via IVF. His results suggest that the very act of creating a child artificially in a lab may be enough to drive epigenetic change. A product of gene editing and cloning, GElvis would be conceived not under a duvet, but in a petri dish. Far from identical, Elvis and GElvis would be epigenetically different from their initial moment of creation.
An Infinite Number of Elvises
So, all of us – Elvis and GElvis included – are a product of nature and of nurture, with epigenetics bridging the gap between the two, but it’s still not enough to explain how we turn out the way we do. There’s another factor at work.
In 2013, Gerd Kempermann of the Dresden site of the German Centre for Neurodegenerative Diseases and colleagues took 40 genetically identical mice and raised them all in the same identical environment. If nature and nurture are all there is, he reasoned, then each of the mice should turn out the same. But it didn’t quite pan out that way.
The team housed their mice in a five-storey rodent ‘des res’ kitted out with flower pots, plastic tubes and toys, then recorded their movements over a three-month period. What they found was that although the patterns of movement were similar at the start of the experiment, by the end of it, they were very different indeed. Some animals were bold and explored a lot, while others had no such wanderlust. ‘The animals developed different personalities,’ says Kempermann. Genetically identical pups grew into very different adults.
Kempermann thinks the differences are a consequence of the way each individual animal interacted with its environment. A slightly more active mouse, for example, might explore more than a less active one. It might bump into more of its cagemates, climb on a flower pot, tumble down a tube. This might fuel its adventurous spirit, make it better at climbing, more likely and able to seek out new experiences. All of the mice lived in the same environment but they experienced it very differently. ‘Over time, the rich environment lost its sameness,’ says Kempermann.
It’s the same for children growing up in the same family. ‘If you ask parents if they treat their kids differently, they say no. But if you ask their children the same question, you’d swear they’re growing up in a different family,’ says Robert Plomin. ‘“It’s not fair!” is the norm.’ Supposedly shared environments, such as home and school, and common life events, such as birth and bereavement, are experienced differently not just by twins, but by all family members. It’s this non-shared environment, unique to the individual, that must have caused Gerd Kempermann’s mice to end up different, and that helps to shape each and every one of us, too.
In addition, our lives are full of uncertainty and chance. Bill Clinton, famously, was inspired to go into politics after shaking the hand of John F. Kennedy. And I, less famously, was inspired to take up writing many years ago after I injured my knee dancing to Sinitta’s ‘So Macho’ in a Glaswegian nightclub, and for months was unable to go out partying with my friends. Serendipity, unpredictable by its very nature, plays a major role in the way our life stories are written. Who knows what would have had happened if Presley’s vocal cords had been nobbled by a random throat infection in his early years? Or what if Elvis’s natural twin, Jesse, had survived? Perhaps the boys would have been too busy scrapping or trading bubble gum cards to take much interest in music. The fact is, even if you created an infinite number of GElvises, turned back time and brought them up in a carbon copy of Presley’s 1930s America, they’d still all end up different.
Jailhouse Rock
Although it’s technically possible to decode Elvis Presley’s genome from his quiff, Presleyfy a human cell and create a baby from it, that child will never ‘be’ Elvis. At this point, depending on where they work, the scientists involved could have broken several laws, not to mention social and ethical taboos. Under the UK Human Tissue Act of 2004, it is illegal to analyse, without consent, the DNA of someone that has been dead for less than 100 years. A somewhat arbitrary cut-off, this means that researchers at the UK’s University of Leicester who are working to decode the genome of a different king – King Richard III – are several hundred years in the clear, while anyone trying to sequence Elvis’s genome on British soil could find themselves doing the ‘Jailhouse Rock’.
Human reproductive cloning is widely banned (see Chapter 2) and in 2002, after an in-depth review on the subject, the President’s Council on Bioethics wrote to the then US president, George W. Bush, to advise him that ‘cloning-to-produce-children is not only unsafe but also morally unacceptable, and ought not to be attempted.’ It smacks of eugenics, relegates the creation of human life to a manufacturing process, and leads to a weird and uncomfortable world in which a father could become ‘twin brother’ to his own ‘son’.
To top it all, the tiny, cloned human embryo would have been genetically modified. Every cell in the developing clone’s body would be derived from the original Presleyfied egg, which means that when the clone grows up and thinks about having tiny Presleys of his own, the three million laboratory-engineered changes would also be present in his sperm. These changes would then be passed on from one generation to the next.
It wouldn’t be the first time scientists have edited heritable genetic changes into human embryos. In April 2015, Chinese researchers announced that they had used CRISPR to repair a defective disease-causing gene in human embryos. The preliminary research, performed deliberately on non-viable human embryos (because the scientists never planned to let the embryos grow into babies) was a step towards trying to correct the single mutated gene that causes beta-thalassemia, a potentially fatal blood disorder. Despite the good intentions, the research played into a heated debate. A month earlier, researchers writing in the journal Nature called for a global moratorium on the genetic modification of human embryos, citing ‘grave concerns’ over ethics and safety concerns that it seems were justified. When the Chinese researchers ran their experiments, the gene editing didn’t go as well as they had hoped. Sometimes CRISPR failed to cut the DNA, other times it cut it in the wrong spot, potentially creating new problems. The technique only worked properly in a fraction of the embryos tested and when it did, the embryos sometimes ended up being a mix of edited and non-edited cells, and not the pure genetically modified embryo of design. As present technology stands, genome editing, it seems, is not without risk.
So we create GElvis despite the grave societal and moral peril to us and him, and for what? To create someone that looks a bit like Elvis but who, inevitably, will be a different person with a different life story. Cells can be cloned. ‘Selves’ cannot. From the moment it is created, every new life is unique, and it only becomes more unique as time goes on. And that, my friends, is the wonder of you.
Elvis truly was one of a kind. Geneticist Neil Hall from the University of Liverpool has calculated how many more babies Gladys and Vernon Presley would have to have had before they produced one that was genetically identical to Elvis. His calculation takes into account the random divvying up of the two sets of 23 chromosomes that happens when cells divide to make sperm or egg, as well as the swapping around of genetic material within chromosomes that accompanies the process. He estimates that Gladys and Vernon Presley would have to produce another 41, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000, 000,000 children before Gladys popped out a natural Elvis clone. That’s 41 followed by 126 zeros. ‘This is a ridiculously large number and quite possibly a massive underestimate,’ says Hall. It also doesn’t take into account the fact that after a third child, married couples rarely have sex again, or that Gladys and Vernon are, in fact, dead. To put the number in context, the number of atoms in the observable universe is thought to be around 4 with 79 zeros after it. ‘Presley’s number,’ as it shall henceforth be known, is 48 zeros bigger than that. It’s mind-bogglingly huge, and a testament to the uniqueness that was Elvis.
There is, however, another way to bring some much-needed ‘Elvisity’ back into the world. Let me explain. When Elvis died, in 1977, it’s estimated there were around 170 Elvis impersonators. By the year 2000, that number had increased to around 85,000. Plot the figures on a graph, take into account projected population growth, do some dubious stats and what we find is that by 2043, 1 in 4 of us will be an Elvis impersonator. If you’re reading this book on a bus please look at the person sitting next but two to you. Now imagine them with a glistening, three-inch quiff. Now stop staring. I think they’ve noticed. More excitingly still, extend the line on the graph to its logical conclusion and what we see is that by 2050, every living man, woman and child on the planet will be an Elvis impersonator. We may be able to ‘de-extinct’ a person with the same genetic code as Elvis, but it won’t be Elvis. We can’t recreate Elvis. We shouldn’t recreate Elvis. We don’t NEED to recreate Elvis. His music is still with us and one day soon we’re all going to be singing it. Ladies and gentlemen, put on your jumpsuit, fasten your cape and fashion your hair into an Elvis-style quiff. You have a little over a decade to learn the lyrics to ‘Suspicious Minds’. But in the meantime, Elvis really has left the building.
NOTES
1 ‘Burning Love’ was my request. My husband wanted ‘Heaven Knows I’m Miserable Now’ by the Smiths.
2 The website still exists and can now be found at americansforcloningelvis.bobmeyer99.com.
3 On a more macabre and unpalatable note, body parts from dead celebrities are also up for grabs. Napoleon’s penis, for example, is said to be in the possession of one Evan Lattimer, daughter of a New Jersey urologist who bought the item at a Paris auction in 1977. Apparently removed at autopsy by Napoleon’s doctor, the shrunken member is said to be around 4cm (1.5in) long. Josephine probably wasn’t that disappointed when he said ‘not tonight’.
4 Presumably pre-Pepsi commercial.
5 But no one bought it.
6 Just to wind up the creationists.
7 Just to wind up Richard Dawkins.
8 Unforgiveable!
9 This is largely the fault of the men in your family. Men make lots of sperm, while women make comparatively few eggs. So the cells that divide to produce sperm do so much more frequently than the cells that divide to make eggs. Men make more mistakes. It’s scientifically proven.
10 ‘Presleyfication’ is a sadly under-used piece of made-up jargon. It refers to the act or process of modifying a human genome so that it becomes the same as Elvis Presley’s.
11 Just so we’re all reading from the same page, let’s pronounce the ‘G’ in ‘GElvis’ softly, like the ‘G’ in ‘gene’.
12 On 1 February 1976, Elvis famously flew round-trip Graceland to Denver in his private jet so he could buy an 8,000 calorie ‘Fool’s Gold’ sandwich made from a hollowed-out loaf filled with a jar of peanut butter, a jar of jam and a pound of bacon.
13 There are several thousand single-gene diseases, so called because they are caused by defects in single genes. So there is a ‘gene for’ Huntington’s disease and cystic fibrosis. But the vast majority of human diseases and characteristics are complex, caused by poorly understood combinations of multiple genes and other factors.