GM vs. selective breeding - what's the difference?

Discussion in 'CycleChat Cafe' started by Globalti, 30 May 2008.

  1. Globalti

    Globalti Legendary Member

    Okay, okay, I know GM means taking genes from one species and inserting them in another, whereas selective breeding is a much slower process where you just give Mother Nature a guiding hand.

    But in the end aren't both processes achieving exactly the same effect? If so, what should we have to fear from GM as long as we took precuations to ensure the resulting hybrid didn't rampage out of control?
  2. Night Train

    Night Train Maker of Things

    Greater Manchester
    I think slective breeding is just making the best of the attributes of a particular species whereas GM is crossing of species that wouldn't/couldn't happen by any natural means. I know that some plant species are crossed to get sweeter and more edible crops but it is still a close relationship between the two.
    It would be very difficult to get animal and vegetable to cross by any natural means for example. Or human and animal for that matter though there are people who have a preference for that sort of thing.

    The other aspect of it is slective breeding automatically filters out those that would not work, are faulty or are non fertile but GM, it would seem, doesn't.
  3. Maz

    Maz Legendary Member

    GM food is a definite no-no.
    Have you ever seen the B-Movie Attack of the Killer Tomatoes?
    Is that what you want? IS THAT WANT YOU WANT?! Coz that's what'll happen!
  4. wafflycat

    wafflycat New Member

    middle of Norfolk
    Wot Night Train said. Selective breeding is simply doing it 'naturally' taking the best naturally occurring attributes and breeding them on in a natural way. GM is utterly different in that it is used to produce things that would not be occurring in the normal environment e.g. cress that glows in the dark as it's had firefly DNA inserted into it...Obviously fireflies are shafting cress all the time naturally to produce mutant offspring ;)

    The main worry I have about GM where DNA from a species that would never naturally be found in a.n.other species is the potential increase in risk of diseases from one species crossing over into another. And as has been shown in many cases, where a disease crosses the species barrier, it can become more virulent.
  5. jonesy

    jonesy Legendary Member

    I agree.

    I think we need to get the 'super weed' risk into perspective. Almost by definition domesticated plants are less suited to the natural environment than their wild relatives. e.g. the fruits and seeds are bigger than they need be, which imposes a significant energy penalty. Domestic grains are more tightly bound to the stalk to make them easier to harvest in one go, reducing their ability to seed themselves. Stalks are often shorter, making them more vulnerable to mildew etc. You often see wheat, barly etc growing 'wild' on the fringes of fields where it has been grown the previous year, but never in places like woodlands or natural grasslands where they will be out-competed by hardier wild species.

    GM modifications are intended to make the crops even more suited to our needs, which is likely to make them even less suited to the wild. For example, the genes for herbicide resistance offer no evolutionary benefits in environments where the plants aren't sprayed, which is most places where wild plants grow, so why would they spread? They are likely to involve some cost to the plant, even if only in additional energy consumption, so the artificial modification is likely to die out naturally within a few generations of 'escaping' into the wild. Let's not forget that changing one or two genes is extremely crude compared to natural evolution and therefore very unlikely to come up with something able to compete in the wild with naturally evolved competitors. (Invasive species like Japanese Knotweed aren't GM of course, instead they are an essentially natural species placed into an environment where they have few pests and competitors, so aren't a valid example of a problem specific to GM).
  6. Night Train

    Night Train Maker of Things

    Greater Manchester
  7. Night Train

    Night Train Maker of Things

    Greater Manchester
    My main concern with GM is the speed of the advancing research. With selective breading there has been a long slow process to get what is desired and during this process much is learnt about the side effects of selecting the wrong crosses.
    With GM it is such a quick process to, say transplant a jelly fish gene into a tomato or a bit of human gene into a pig, that there little time spent investigating the potential side effects and long term problems that may happen.

    Also in terms of human genes, at what point do we need to apply human rights to the hybrid that is produced never mind the issues of ownership.
    Currently a company can claim ownership of a hybrid that contains a tiny amount of human genes. If that percentage of human attribute is increased at what point does it become more human then not.

    If someone has a child that is modified to provide cells to help another does that child become the property of the research lab?
  8. red_tom

    red_tom New Member

    East London
    Norman Borlaug is your man.

    There's an argument that whilst there are people starving in the world then the benefits that the potential increases in yield that GM could bring far outweigh the risks. I think this is something that we, in a country where food is abundant, often overlook.
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