TheBelgian blue is an ugly but tasty cow that has 40% more muscle than it should have. It is the product of random mutation followed by selective breeding—as, indeed, are all domesticated creatures. But where an old art has led, a new one may follow.By understanding which genetic changes have been consolidated in theBelgian blue, it may be possible to design and build similar versions of other species using genetic engineering as a short-cut.And that is precisely what TerryBradley, a fish biologist at the University of Rhode Island, is trying to do. Instead of cattle, he is doing it in trout. His is one of two projects that may soon put the first biotech animals on the dinner table. The other project is led byAquaBounty.
It is one thing to make such fish, of course. It is quite another to get them to market. First, it is necessary to receive the approval of the regulators. InAmerica, the relevant regulator is the Food andDrugAdministration ( FDA、, whichAquaBounty says it has been petitioning for more than a decade and which published guidelines for approving genetically engineered animals in 2009.AquaBounty has now filed its remaining studies for approval, and hopes to hear the result this year.DrBradley has not yet applied for approval. The FDA、is concerned mainly with the healthfulness of what people put in their mouths, and it seems unlikely that the new procedures will yield something that is unsafe to eat.But what happens if the creatures escape and start breeding in the wild For that to be a problem, the modified fish would have to be better at surviving and reproducing than those honed by millions of years of natural selection. On the face of it, this seems unlikely, because the characteristics that have been engineered into them are ones designed to make them into better food, rather than lean, mean breeding machines. But there is a chink in this argument.As MarkAbrahams, a biologist at Memorial University in Newfoundland, points out, it is not just the fish that have been modified by man, but also the environment in which they could escape. Many of the creatures that eat salmon and trout, such as bears and some birds, have had their ranks thinned by human activity.DrAbrahams thinks it possible that fast-growing salmon could displace the natural sort in places where predators are rare. AquaBounty is addressing such concerns by subjecting developing eggs to high pressures. The result, if all goes well, will be that animals follow plants down the biotech route. Whether people will actually want to buy or eat the new fish is a different matter— though they buy the meat ofBelgian blue cattle at a premium. Perhaps clever marketing could make "double-muscled" fish into a premium product, too. If people will pay extra for meat from a monstrosity like theBelgian blue, anything is possible. What concerns MarkAbrahams most is that the modified fish will ______. A、escape into the wild to breed abundantly B、break the rule of natural selection C、generate unknown harm to human body D、replace natural fish as a result of less predator
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