\u201cA normal gene gets passed on to 50 per cent of the offspring,\u201d says Harvey-Samuel. \u201cWith a gene drive, the idea is you change it in such a way that it\u2019s passed to more than 50 per cent of your kids. It doesn\u2019t necessarily need to get to 100 per cent to be effective, but the closer you are to 100, the faster it will spread through the population.\u201d<\/p>\n
Another scientist compares it to creating a coin with two heads. A gene drive beats the normal odds.<\/p>\n
Other non-GM approaches are being considered to deal with the malaria issue. For example, scientists have infected male mosquitoes with the\u00a0Wolbachia<\/em>\u00a0bacterium, making the females they mate with infertile. Millions have been released on Hawaii.<\/p>\n But Harvey-Samuel believes no one single method will save Hawaii\u2019s native birds. His work is at a very early stage, and it could be many years before there are any genetically modified mosquitoes ready to be released. Even then, the team would have to pass numerous regulatory hurdles in Hawaii.<\/p>\n That doesn\u2019t stop scientists opposed to GM organisms being alarmed. At a recent conference of the IUCN (International Union for Conservation of Nature), they proposed there should be a moratorium on any releases into the wild.<\/p>\n The motion failed, and instead delegates agreed one that creates the first global framework on whether, and how, what the IUCN calls \u2018synthetic biology\u2019 should be researched for the benefit of nature conservation.<\/p>\n \u201cThe policy should not be interpreted as supporting or opposing synthetic biology,\u201d the IUCN says.<\/p>\n \u201cIt provides a framework for case-by-case decision-making, establishing a mechanism to guide how, when, and under what conditions synthetic biology applications might be approved and introduced.\u201d<\/p>\n Nevertheless, many conservationists are unhappy about the current direction. \u201cThere is no evidence that these technologies will help protect or restore nature,\u201d says Franziska Achterberg, head of policy at Save Our Seeds, one of a number of organisations that supported the moratorium proposal.<\/p>\n She says there are only two examples where wild species have been successfully genetically modified, and neither have provided conservation benefits. One is the creation of what biotech company Colossal calls a\u00a0dire wolf\u00a0\u2013 in reality, a grey wolf with some genes that have been tweaked, Achterberg points out.<\/p>\n \u201cLook at what IUCN experts say about this,\u201d she says. \u201cIt is an engineered grey wolf that could threaten wild wolves if it got out.\u201d<\/p>\n The other example Achterberg highlights is the American chestnut. The species is Critically Endangered in North America, where scientists have attempted to create a tree resistant to blight.<\/p>\n \u201cInitially, the American Chestnut Foundation supported this work, but by 2023, they felt it wasn\u2019t going anywhere,\u201d she says.<\/p>\n The argument of \u2018Frankenstein\u2019 creatures getting out into the wider environment is understandable.<\/p>\n But Harvey-Samuel is developing GM mosquitoes for an island situation, and the same is true of Paul Thomas at the University of Adelaide \u2013 his work is looking at creating a gene drive that inactivates female fertility in mice. Why mice?<\/p>\n Because where they \u2013 and other rodents, especially rats \u2013 have been released onto remote islands, they have caused conservation havoc, feeding on ground-nesting seabird eggs and even the chicks, literally eating them alive.<\/p>\n Of course, conservationists have successfully eradicated invasive rodents using poison baits on large islands such as South Georgia and small ones like Lundy in the Bristol Channel, but this has never been a completely satisfactory method.<\/p>\n \u201cIt\u2019s expensive, labour-intensive and involves the release of toxins that result in secondary poisonings,\u201d says Thomas. His laboratory work is at least five to 10 years away from producing anything that could result in an animal that could be used in the field, and he doesn\u2019t have any specific islands in mind where it could have practical applications.<\/p>\n But there are obvious examples: Socorro and San Jos\u00e9 off the coast of Mexico; Gough Island in the South Atlantic; and\u00a0Floreana in the Gal\u00e1pagos archipelago\u00a0are just four of many. Thomas also believes that genetic modification can be done in such a way that limits, or even eliminates, broader concerns.<\/p>\n \u201cWe are actively trying to develop the technology so that it\u2019s specific for a particular target population,\u201d he says. Invasive rodents on a small island tend to have all come from a small number of founder individuals, and are therefore genetically homogenous.<\/p>\n \u201cThe idea is to find a genetic predisposition on the island population that\u2019s not in those on the mainland,\u201d he says. Another idea would be to create an in-built obsolescence within the gene drive \u2013 \u201cforming it in such a way that it breaks down over time.\u201d<\/p>\n None of this satisfies the sceptics. Joann Sy, scientific advisor at Pollinis, which was the moratorium proposal\u2019s main sponsor, says it all represents an unwelcome and unnecessary \u201cparadigm shift\u201d in the way conservation is carried out worldwide.<\/p>\n As Sy says: \u201cIt is very dangerous because we see this as reshaping how we intervene in nature and reframing the purpose of what we do. We would like to refocus the conversation on protecting nature and how we do that.\u201d<\/p>\n Some 30 years on from the height of fears about GM crops, today they\u2019re grown over some two million km\u00b2, an area nearly four times the size of France. They are grown in 27 countries, with the US, Brazil and India the three biggest adopters of the technology.<\/p>\n Many groups, such as Greenpeace, which made headlines around the world when activists destroyed a field of GM maize in Norfolk in 1999, no longer actively campaign on the issue. But there is still criticism.<\/p>\n GM crops have failed to deliver on the original promises made by biotech firms, it is argued, with some conservationists saying they are a distraction from truly sustainable farming. In short, they haven\u2019t destroyed the world \u2013 but they haven\u2019t saved it either.<\/p>\n Paul Thomas understands the concerns of people about GM animals negatively impacting nature conservation: \u201cResponsible development of what we\u2019ve got is important.\u201d<\/p>\n But time is running out for Hawaii\u2019s honeycreepers. At some point, the state authorities must decide either that the use of GM technology can be their saviour, or that adopting such a policy is taking playing God too far.<\/p>\nThe GM debate<\/h2>\n
Eradicating invasive species<\/h2>\n
A \u201cparadigm shift\u201d in conservation<\/h2>\n