Not a silly question at all, a very important question.
In conventional breeding, the genes from the two parents are mixed up, so that a new creature is created that combines the traits of the two parents. This combination isn’t a simple halfway house, partly because the genes you get from one parent may not be expressed in that parent; you can get a gene for blue eyes, even if your parent has brown eyes. Also, there is a chance of mutation, that some new genes have been created, for example by errors on cell division, or exposure to a chemical. Most of these mutations make little or no difference, some or harmful, a few are improvements. Conventional plant breeding tries to create more mutations, in the hope that some of them will be useful.
Selective breeding is when people breed particular plants and animals together so that there offspring have more of the traits that you want. This is why there are so many breeds of dogs; dog breeders choose the parents hoping that the puppies will have particular characteristics. In itself this is not harmful. However, sometimes the breeding can also bring together harmful characteristics, which is why some breeds of dogs are prone to back or breathing problems.
In principle, GM is no different to any other kind of selective breeding, except that only small sections of DNA are moved around, rather than whole groups (or chromosomes). This makes GM safer than conventional breeding, as the chances of harmful genes being moved around at the same time by accident are less.
I’m with Les on this, scratty, although I am certainly not an animal breeder. Any breeding, whether conventional, selective or with the use of GM has the potential to improve or make worse, save or harm, or have no impact at all. The method is irrelevant, the change you are trying to make is the key.
I’d just like to chip in on one thing In response to the replies to Scratty’s question by Les and Julian. Altho’ we have much to learn about animal welfare, there is no reasonable room at all for doubt, that certain general kinds of industrially concentrated production cause greater harm and suffering to animals than do other possible techniques. Amid many complexities, this is the big issue with ‘factory farming’.
The kinds or degrees of any harm that might be inflicted on animals specifically by GM is a related – but quite distinct matter. And it depends on a range of factors. But one thing is sure. It is highly misleading to claim that there are no grounds at all for identifying particular possible concerns with GM. Of course – as with other such complex issues – there is room for disagreement. But to deny there is a specific issue here for GM is not helpful to reasonable debate. I’ll try to explain why.
For instance, it is perfectly possible that the availability of GM techniques will help encourage the world’s animal farming systems to go down a more industrially-intensive path than might otherwise be the case. This is the kind of self-reinforcing economic effect that I have raised in other answers in this Forum. These kinds of ‘positive feedback’ dynamic are an absolutely routine part of the way in which industrial systems develop.
Industrial intensive systems, by definition, involve putting a greater emphasis on intensifying conditions of production and concentrating dependence on particular kinds of inputs. Although not specific to GM, such pressures are certainly very strongly represented in the economic and industrial drivers for many GM technologies. It is these pressures that are responsible for particular adverse effects on animals, as in battery farming of poultry.
So, to the extent that GM helps exert a self-reinforcing effect in taking general animal husbandry technologies down a more industrially intensive (rather than, say, a more ecologically-sophisticated) path, then it is clear that GM techniques certainly could end up compounding the extent and degree of harm that industrial production can do harm to some animals.
So, let’s please not hear so many unqualified assertions that “GM is no different”. It could be. GM is as distinct in its economic and technological dynamics, as in its implications for ecology and food. We can legitimately debate whether these effects are positive or negative. But we shouldn’t try simplistically to rule out even the basis for any question that there are issues to be discussed here.