Marker-Assisted Breeding
Jan. 5th, 2010 03:40 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
deaneA lot of people are frightened by GM (genetically modified) food. Most of that fear is overblown as there's nothing done in the GM labs which couldn't also happen as a result of traditional breeding techniques or natural evolution. For example, in nature there are a variety of ways for genes to jump between species, without any help from humans. It's possible that tomorrow one of the genes which create carcinogens in tobacco will cross over to corn, giving us killer corn. Possible, but extremely unlikely.
Because traditional plant and animal breeding techniques speed up the rate at which genes are mixed, that necessarily means an increase in the chances of getting killer corn or exploding cows. GM techniques speed up the process even more, which increases the risk. But we're still talking about a minute probability.
In some ways GM is actually safer than traditional breeding or even leaving nature to run its own course. A traditional breeder mixes entire genomes in an effort to transfer a handful of key traits, without knowing anything about the bulk of those genomes. In trying to add drought resistance a plant breeder might inadvertently introduce a host of dangerous genes into a previously harmless plant. Nature is even worse: it doesn't care if it breeds killer corn, just so long as that improves the corn's chances of survival. By contrast, GM labs are extremely selective in the genes that they transfer, only using those whose effects they understand (or think they do!) and actively filtering out those which could cause harm.
However, even with the all that care, the fact that GM techniques do in days what traditional breeding takes decades to accomplish, and evolution millennia, means that the risks of a bad outcome, while still minute, are higher. Against that tiny chance of danger must be weighed the certain deaths of millions who would starve without the improved productivity of GM crops.
Marker-assisted breeding may provide a useful middle ground. Modern genetic techniques are used to quickly identify plants which have the desired genes. These are then cross-bred in the traditional way, without any of the laboratory techniques which generate so much angst. The offspring are then genetically surveyed and any which did not pick up the desired genes are eliminated. This approach allows traditional breeding to be more targeted and to achieve results more quickly. As our understanding of the genomes of various plants and animals grows, marker-assisted breeding should become safer than traditional breeding since we will know exactly what is being bred.
Marker-assisted breeding will still be slightly more dangerous than letting nature run its course, and it won't be capable of delivering nearly as many benefits as GM, but by eliminating the laboratory techniques which seem to worry it might allow at least some of the benefits of GM to be spread more widely.
Because traditional plant and animal breeding techniques speed up the rate at which genes are mixed, that necessarily means an increase in the chances of getting killer corn or exploding cows. GM techniques speed up the process even more, which increases the risk. But we're still talking about a minute probability.
In some ways GM is actually safer than traditional breeding or even leaving nature to run its own course. A traditional breeder mixes entire genomes in an effort to transfer a handful of key traits, without knowing anything about the bulk of those genomes. In trying to add drought resistance a plant breeder might inadvertently introduce a host of dangerous genes into a previously harmless plant. Nature is even worse: it doesn't care if it breeds killer corn, just so long as that improves the corn's chances of survival. By contrast, GM labs are extremely selective in the genes that they transfer, only using those whose effects they understand (or think they do!) and actively filtering out those which could cause harm.
However, even with the all that care, the fact that GM techniques do in days what traditional breeding takes decades to accomplish, and evolution millennia, means that the risks of a bad outcome, while still minute, are higher. Against that tiny chance of danger must be weighed the certain deaths of millions who would starve without the improved productivity of GM crops.
Marker-assisted breeding may provide a useful middle ground. Modern genetic techniques are used to quickly identify plants which have the desired genes. These are then cross-bred in the traditional way, without any of the laboratory techniques which generate so much angst. The offspring are then genetically surveyed and any which did not pick up the desired genes are eliminated. This approach allows traditional breeding to be more targeted and to achieve results more quickly. As our understanding of the genomes of various plants and animals grows, marker-assisted breeding should become safer than traditional breeding since we will know exactly what is being bred.
Marker-assisted breeding will still be slightly more dangerous than letting nature run its course, and it won't be capable of delivering nearly as many benefits as GM, but by eliminating the laboratory techniques which seem to worry it might allow at least some of the benefits of GM to be spread more widely.
(no subject)
Date: 2010-01-06 03:54 am (UTC)