Naked Science Forum

Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: Roland Williamson on 11/07/2009 08:30:02

Title: Why should GM seeds be sterile?
Post by: Roland Williamson on 11/07/2009 08:30:02
Roland Williamson asked the Naked Scientists:
   
Re: Banana Medicine by Harriet Dickinson
  
Love the site (http://www.thenakedscientists.com) - better get that in!
  
I am one of those totally torn by the issue of GM crops. I understand the argument (I think) but the leap forward from annual selection and breeding of crops is over shadowed by the unnecessary control by the developers whereby they retain control of the seeds. How can that benefit man? Politics has starved far more than ineptitude.
  
Regards, Roland Williamson.

What do you think?
Title: Why should GM seeds be sterile?
Post by: RD on 11/07/2009 16:48:30
The sterility is not just for economic reasons, (so the farmer has to buy new seed every year).

Theoretically sterility should prevent GM crops being mixed or crossbred with “natural” crops.

If you were a “GM-free” farmer you would not want your neighbours genetically modified crop being mixed with or crossbred with your “natural” crop. 
Title: Why should GM seeds be sterile?
Post by: LeeE on 11/07/2009 17:42:21
The most important reason is, as RD says, to prevent crossbreeding.  However, the problem is potentially far more serious than just contaminating non-GM crops; there is a risk of the GM crops not only interbreeding with non-GM crops and out-evolving them, and in effect, killing them off, but also interbreeding with dissimilar plants and killing them off too.  When I say 'killing them off' here I'm referring to the GM organism mutated crops supplanting the non-GM varieties in the same way that evolution works; the mutated plants might survive better than the original plants, leading to their decline and extinction.

The problem I have with GM crops, and GM meat too, for that matter, is that I think the testing period has been far too short.  I can't see an intrinsic problem with GM; it seems like a very good idea to me.  It's just that considering the importance of what we're dealing with here, and how it's such a fundamental part of our diets, I think a couple of decades is too short a testing period; I think they should have been tested for a couple of centuries before being declared safe.  We just don't know what the long term effects will be, not just on individuals but across generations.
Title: Why should GM seeds be sterile?
Post by: _Stefan_ on 11/07/2009 17:54:50
Why don't farmers/selective breeders have to jump through the same hoops? Their organisms are just as GM as scientifically GM organisms.
Title: Why should GM seeds be sterile?
Post by: Madidus_Scientia on 12/07/2009 03:00:42
Can we afford to wait a couple of centuries?

And as _Stefan_ says, we've already been genetically modifying our food for centuries. 2000 years ago a banana tree as we know it didn't exist, but after selective breeding we today have a pretty efficient fruit producing tree. If we can artificially GM our crops to produce more food faster then why not, with the worlds population as it is today we're going to need all the food we can get.
Title: Why should GM seeds be sterile?
Post by: LeeE on 12/07/2009 12:58:08
Selective breeding is not really the same as genetically modifying something.  With selective breeding you can only combine traits between organisms that can already interbreed whereas GM is most often used to combine traits from dissimilar organisms, ones that cannot naturally interbreed.  GM is not just about making selective breeding more efficient.

There are risks associated with selective breeding, of course; inbreeding being a classic example.  The scope of the risk though, is confined to organisms that can already interbreed, and if they can already interbreed it's likely that that specific combination has already occurred and failed, or succeeded.  With GM the potential scope for risk is unknown.

Can we afford to wait a couple of centuries?  Why has that factor become an issue now and did not arise before GM was possible?  Is it really just coincidence that GM became necessary only when it became possible?

The question is can we afford such a risk?  What is certain is that nothing works 100%.  There will certainly be GM programs that fail, and most of these will be found and discarded before going into 'production', but similarly, the detection process won't be 100% successful either and at some point it is almost inevitable that something dangerous will not be detected before the problems become apparent.  This has happened many times already in the field of pharmaceuticals, so why do people expect it to be different with GM?  Relatively few people need to take pharmaceuticals, especially on a long-term basis, but with food you're going to be hitting a lot more people with something they'll be using constantly.
Title: Why should GM seeds be sterile?
Post by: _Stefan_ on 12/07/2009 15:52:14
I don't think it means much whether 2 organisms can interbreed or not. When a new mutation occurs in one line, or an allele in one line has never been experienced by the other line, this is no different from introducing a trait from an entirely different species. And in both cases, the possible effects are not known.

Also, when selective breeders produce new strains traditionally, they have no idea how safe it is for the environment or to eat, because they are new.

The GM issue needs to be examined in perspective.
Title: Why should GM seeds be sterile?
Post by: Don_1 on 13/07/2009 08:23:31
I must agree with LeeE, GM and selective breeding are different. You cannot take a trait present in wheat and get it into a tomato by selective breeding, but you can by GM.

It is not simply the long term effect on the plant concerned, but also the long term effect on other plants/insects/wild animals which may be indirectly linked to that plant. Even in the short term we have seen problems with GM maize pollen killing Monarch butterfly larvae. Any break in the natural food chain can have dire consequences.

To my way of thinking, selective breeding is OK up to a point since it is something which nature will allow, but GM is contrary to natural crossbreeding and has the potential to result in something which could be dangerous to those which rely on it and have a knock-on effect both up and down the food chain.
Title: Why should GM seeds be sterile?
Post by: _Stefan_ on 13/07/2009 09:28:13
Given enough time, you could selectively breed to produce almost any trait. We know this because it's already happened through evolution as well as artificial selection. There are also countless examples of convergence.

The GM butterfly-killing-crop was engineered to produce a pesticide as far as I recall. Any plant that produces a pesticide could have had this effect, GM or not.

As Lee said earlier, there's nothing intrinsically bad about GM.

Please, put GM in some perspective.

By the way, I am not advocating against research into the safety of GM.
Title: Why should GM seeds be sterile?
Post by: LeeE on 13/07/2009 17:36:53
As I said in my first post, I do think that GM is a good idea; the problem is that there has been insufficient time to adequately test it.  The motives for it's early roll-out and aggressive promotion have nothing to do with saving the Earth, it being claimed by some that it is now our only viable option; it's being pushed out so aggressively, even to the extent that attempts have been made to restrict non-GM alternatives, purely to turn a profit.
Title: Why should GM seeds be sterile?
Post by: Don_1 on 13/07/2009 17:54:01
The incident with the monarch butterfly, I think, is evidence enough that much, much more evaluation of GM crops and their effect on other plants/insects is imperative before any GM plant is released into the open environment.

The big problem at the moment, is that most research is being done by, or funded by the companies keen to promote their GM products. It is, therefore, not so much biased as blatantly predestined to come out in favour of GM.
Title: Why should GM seeds be sterile?
Post by: LeeE on 13/07/2009 18:23:07
Heh - a bit of an after thought, but I just thought I'd better mention that it is not the seeds that are sterile but the plants that grow from them.
Title: Why should GM seeds be sterile?
Post by: thedoc on 18/05/2010 18:54:10
Go to the podcast page. (http://www.thenakedscientists.com/HTML/podcasts/show/2010.05.16/)
or [chapter podcast=2580 track=10.05.16/Naked_Scientists_Show_10.05.16_6279.mp3](https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.thenakedscientists.com%2FHTML%2Ftypo3conf%2Fext%2Fnaksci_podcast%2Fgnome-settings-sound.gif&hash=f2b0d108dc173aeaa367f8db2e2171bd) Listen to the Answer Now[/chapter] or [download as MP3] (http://nakeddiscovery.com/downloads/split_individual/10.05.16/Naked_Scientists_Show_10.05.16_6279.mp3)
Title: Why should GM seeds be sterile?
Post by: echochartruse on 23/05/2010 22:59:23
In Australia there is documented evidence that GM crops cross pollinate
http://www.associatedcontent.com/article/270081/genetically_modified_crosspollination.html
so we may lose the original strain forever.