The Medicine We Fear Instinctively


Genetically modified mosquitoes could be the solution to Hawaii’s quickly disappearing avian population, including the island’s famous honeycreepers. PHOTOGRAPH BY RESOURCE HAWAII / ALAMY

Michael Specter writes frequently (but not exclusively) about frighteningly unpleasant, sometimes devastatingly horrible topics with grace not often found in technically rigorous writing. Here, in a short post, he addresses the prospects of a technology many rightly fear and its potential to address many rightly feared environmental (the one in the title below obviously catches our attention) and health challenges:



Every four years, thousands of environmentalists gather at the World Conservation Congress to assess the state of the planet, and to consider what might be done to protect it. This year’s meeting ends Saturday, and the news this past week, with a few exceptions, has not been cheerful. Four of the six great-ape species are critically endangered, which means they are one step from extinction, according to the International Union for Conservation of Nature, which organizes the congress. So are thousands of other species. The eastern gorilla—the world’s largest living primate—is in particular jeopardy.

The 2016 congress has been held in Hawaii, which is fitting, since the state is often referred to as the endangered-species capital of the world. President Barack Obama, who was born in Hawaii, addressed the conference as it began, shortly after signing a proclamation to create the world’s largest ecological preserve. The act will protect an area of the ocean surrounding the Northwestern Hawaiian Islands that is twice the size of Texas. Nonetheless,nearly ninety per cent of the Hawaiian native plants that the I.U.C.N. has assessed so far are threatened with extinction, and the avian population is quickly disappearing, too—including the island’s famous, melodious, and brightly colored species of honeycreepers. Climate change has played a role, and so have feral cats, invasive rats, and other non-native species. But mosquitoes, which carry avian malaria, are a principal reason that just forty-two of more than a hundred species of native Hawaiian birds remain. Most of them are endangered.

There were no mosquitoes on the Hawaiian islands until early in the nineteenth century, when they arrived on whaling ships. That meant that native birds had no exposure to the diseases that mosquitoes carry, and therefore no immunity. One way to protect the birds from malaria has been to kill mosquitoes with chemicals. But mosquitoes can breed in less than a teaspoon of water, and can do so nearly anywhere in Hawaii; their eggs are often inaccessible, hidden in rocks, caves, and the hollows of trees. Poison that can kill mosquitoes frequently also kills the plants and animals that surround them.

Science may offer a solution, however. There are now genetic technologies that, at least in theory, are environmentally benign, but could wipe out the mosquitoes that have decimated the birds of Hawaii—and those that endanger human health as well. That has many conservation ecologists tremendously excited. “These species are on the verge of extinction, and there may be a way to save them,’’ Ryan Phelan, the executive director of Revive & Restore, said. The group, based in California, seeks to apply genomic solutions to conserving endangered species. At the congress, Revive & Restore held two heavily attended workshops on issues of “genetic rescue.” “It is entirely up to the local community to decide whether these tools might be appropriate, but it’s important to remember the consequences of doing nothing,” Phelan said.

Any sentence that includes both the words “genetic” and “modify” causes controversy—often, as is the case with bird preservation in Hawaii, even before the facts are discussed. Many Hawaiians are particularly sensitive to what they see as the abuses of biotechnology. Critics argue that altering genes to save birds could cause extinctions and other unknown effects, and yet this technology may present the first genuine opportunity to protect these vanishing species.

There are essentially three genetic approaches that might save the birds of Hawaii. The first would be to introduce mosquitoes that have been genetically modified to become sterile, or are programmed to die quickly. This technique is not new: I wrote about the technology for this magazine in 2012, when the British company Oxitec, which stands for Oxford Insect Technology, embarked on an attempt in Brazil, among other places, to eliminate Aedes aegypti, the mosquito species that carries the viruses that cause dengue fever, yellow fever, Chikungunya, and Zika. The data from Brazil demonstrated clearly that, after the release of millions of sterile males, the number of mosquitoes capable of transmitting dengue fever fell markedly. (Only females bite; if they mate with sterile males, their eggs will never mature.)

A related approach involves…

Read the whole post here.


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