Thinking genes

Written by      

Te Papa

What makes for an open, enquir­ing mind? How much is down to nature, how much to nurture? Were the technology available, would you choose genes for your children that enhanced their ability to consider and weigh up challenging alterna­tives? Or genes that made it more likely they adopted a fixed outlook of your choice?

Sculptural double helixes, inter­active displays, illuminated informa­tion panels, repeating audio-visuals, specimens behind glass—all these make “The Genetic Revolution”, showing at Te Papa until January 2006, a stimulating and engaging experience. But the real star of the show is the humble question mark. What do you think? Not only that, have you considered the views of others?

It is none too soon to ask. Few areas of debate seem to arouse pas­sions and antipathies quite like the mind-boggling possibilities present­ed by recent advances in genetic science. The elimination of genetic disorders; cloning; pharming; gene therapy; designer babies; GM/GE crops—each is a battleground atop a minefield straddling a fault line.

“The Genetic Revolution”—ac­tually the American Museum of Natural History’s “The Genomic Revolution”, rechristened and given a touch of local flavour—allows those so inclined to exercise their critical faculties rather than their prejudices. The exhibition offers basic information about actual and potential applications of the emerg­ing biotechnologies, and a range of viewpoints concerning these. It also offers viewers the chance to have their say at automated polling stations, where they can consider questions like those posed above and compare their responses with others’.

The exhibition opens as might be expected: with the decipher­ing of the template for human life known as the human genome, and the double-helical structure of the genomic material—deoxyribonu­cleic acid, or DNA. Here we learn that the human genome, i.e. a single individual’s DNA, is composed of as many as 3.2 billion units of chemical code, each unit being a pair of nucleotide bases—either adenine–cytosine (A–C) or thym­ine–guanine (T–G). A copy of the genome is packed into the nucleus of every dividing cell in the body.

Nearby, dramatic claims for the future scroll across the wall: “We will each carry our individual genome on a wallet-sized computer card.” “Doctors will be able to tailor pharmaceutical treatment to our individual genetic characteristics.” “Gene therapy will make most com­mon surgery of today obsolete.”

From an array of monitors, ex­perts and commentators deliver at­tention-grabbing one-liners: “We’ll have, in a very short time, the entire set of information for how to con­struct a human being from scratch.” “My greatest fear is that there will be an attempt to use the knowledge before we completely understand it.” “We’re slightly afraid to use ge­netics. I think the real problem we’ll face will be a disuse of genetics, not a misuse.”

Moving on, there’s a chuckle to be had from learning that humans have 28 per cent of genes in com­mon with baker’s yeast and 83 per cent with zebra fish (not to men­tion 99.9 per cent with each other). Nearby, the genetic contribution on the one hand, and the environmen­tal on the other, to such qualities as musical ability, athletic prowess and longevity are considered.

But what, precisely, is a gene? The answer can be found in a display entitled “How Genes Work”, which delivers a step-by-step biol­ogy lesson. First up is an introduc­tion to the many different types of cell in the human body (among which red blood cells are alone in not being endowed with a copy of the genome). Next come chromo­somes, the bundles-23 pairs of them (one set from the father, one from the mother)—into which the DNA in the cell nuclei is packed. Then we have DNA itself and the tiny, discrete segments of it known as genes, each featuring a unique sequence of base pairs, which code for how the body develops and functions. Finally, we learn about the translation of genes into proteins—the workhorses that carry out specific bodily functions.

So far so good. But with the genome’s entire sequence of base pairs unravelled, and the processes by which it gives rise to physical attributes starting to be understood, we have only just begun. Such knowledge opens many doors. It also raises a multitude of vexing questions, as much of the remain­der of the exhibition is at pains to make clear.

Take gene therapy. Medical sci­entists can potentially fix numerous genetic disorders by using viruses to deliver so-called corrective DNA to particular cells in a patient’s body. Few would dispute the value of such treatment. But what about gene therapy for purely aesthetic “improvements”, such as eye and hair colour? Or “correcting” human eggs and sperm, perhaps eventually removing particular genetic traits from entire populations?

Or consider genetic enhance­ment—the screening of multiple embryos in the laboratory and the choice of one free of genetic muta­tion known to cause disease. If you have no qualms about this, what about customising babies in the womb for traits unrelated to health, such as muscular strength, singing ability or, again, purely aesthetic qualities—especially given the pos­sibility that “fixing” or “ordering up” one characteristic might well have an undesirable knock-on effect on others? More fundamentally, should one human be allowed to alter another’s genetic make-up?

Passing a panel that raises the spectre of the early-20th-century eugenics movement, we enter a section given over to case studies of people for whom genetic testing has allowed an inherited disorder, or a genetic predisposition to a severely debilitating condition, to be de­tected and diagnosed and, in most cases, effective treatment to be devised. Alzheimer’s disease, phe­nylketonuria (a metabolic disorder that results in mental retardation), Huntingdon’s disease (a degenera‑tive brain disorder)—who wouldn’t do anything to avoid such a fate?

But while you might wish to be tested—even for a disease for which there is currently no treat­ment—what about family members not so keen yet whose susceptibil­ity would also be revealed? And who should have access to your test results? Employers? Health insurers? Immigration officials?

Such ethical dilemmas aside, the benefits genetic science can deliver in the medical arena are manifest and likely to receive some kind of endorsement, however qualified, from all but the most sceptical. More controversial are the rap­idly proliferating applications biotechnologists are coming up with in the food and agricul­tural sectors.

The range of products under research, being developed or already on the market is impres­sive. Some are aimed at improv­ing nutrition: low-cholesterol hens’ eggs; pigs with lean meat; golden rice, a rich source of vitamin A, without which many people die or go blind every year. Others are developed either for resistance—corn that produces its own pesticide to protect it from borer; herbi­cide-resistant soya, corn and canola—or for tolerance—char­donnay grapes that grow in the cold; crops that thrive where drought, heat or salt or toxic metals in the soil are too much for conventional varieties.

Yet others are engineered for a particular growth pat­tern: fast-growing, cheaper­to-produce Atlantic salmon; slow-growing, low-mow grass; slow-ripening fruit and veg­etables with a long shelf life and loads of taste. Then there are the medical applications: bananas containing vaccines for hepatitis, cholera and influenza; tobacco plants that produce antibodies against bacteria that cause tooth decay; mosquitoes incapable of carrying the ma­laria parasite.

The benefits on offer are dazzling, although many con­cerns have still to be addressed. Aren’t there more “natural” ways of feeding the hungry and improving people’s diets? Won’t constant exposure to a pest-resistant crop result in the pest developing its own counter resistance? What happens when GM fish escape into the wild, or wind-blown pollen from GM plants is spread across the countryside? Wouldn’t plants producing pharmaceutical agents release drugs into the environment, where they could be eaten by animals, accumu­late in the water supply or end up in other plants, including food crops?

Cloning offers yet more fas­cinating possibilities: herds of genetically identical transgenic livestock expressing foreign proteins in their milk for the purpose of mass-producing drugs, vaccines and nutritional additives; pigs with internal organs suitable for human transplantation; recently extinct animals raised from the dead. As for human cloning, although this is widely prohibited it is probably only a matter of time before someone gives it a try. But as we learn from a panel on cloning deceased pets, it is inevitable that a clone will behave differently, and even look different, from its original. (Consider how twins—naturally occurring clones—develop unique personalities and physi­cal features.) Fortunately, as for pets, so for dictators. Any attempt to recreate a beloved despot or tyrant is doomed to failure. The most likely ap­plication of human cloning is helping infertile and same-sex couples have children.

Several displays provide a local perspective. One panel is packed with quotations from the often-heated debate in New Zealand over genetic engineering. Here, too, are such memorable images as MAdGE’s four-breasted dairy-woman and a can of Clarkie’s Corn Cover-Up. Visitors are encouraged to write their own views on a label and hang it on a hook for others to see.

For insight into genetic science as it pertains to Maori custom­ary concepts, turn to the three TV monitors provided. Nearby, read about a Bay of Plenty whanau who teamed up with scientists to tackle a form of hereditary stomach cancer. This involved writing down the whanau’s whakapapa (against its usual custom) as well as drawing up a contract to ensure its ethical be­liefs would be respected and that it would retain ownership of all DNA samples taken.

A selection of plant and animal specimens, including moa bones, pressed plants, a small tank of mudfish, another of stick insects, and several stuffed birds, illustrate aspects of genetic research into the evolution, variety and origins of living things. I was interested to learn that New Zealand’s wrens are probably the most ancient passer­ines (perching birds) on the planet; and that reproduction in the largest genus of New Zealand stick insects is entirely asexual.

Back near the entrance to the exhibition, those who book a place in the Learning Lab can find out just how easy it is to extract DNA by doing it themselves. At coloured tables representing the four nu­cleotide bases, they take part in a short practical in which they add detergent, enzymes and ethanol to a dollop of liquefied strawberry in a test-tube and see the stuff of life materialise before their very eyes.

To get the most out of “The Ge­netic Revolution” you will need to concentrate and have your reading glasses on. But the quality of many of the written displays, and the variety of other media employed, so leaven what could easily have been text-book stodge that anyone with a little curiosity and an interest in learning can easily lose themselves for an hour or two. The more who visit, the better equipped society will be to reach wise decisions about genetic manipulation. Those who are fixed in their attitudes to GM will find little here to please them. This is an exhibition for the sane and thoughtful. May they prevail.

More by