[Hollylane]

Originally Posted by dreadgeek

But Hollylane, that strawberry isn't in its natural state. Everything we eat, every fruit and every vegetable and every domesticated animal has been genetically modified. The difference between genetic engineering and what humans have been doing since we invented agriculture is two-fold:
1) Instead of doing things blindly we are being far more targeted and subtle with it.
2) We are able to across the species barrier in ways we couldn't before.

Other than that, the essence of what is happening is exactly the same. We are taking genes and selecting the ones we want/need for our purposes. When I say we are no longer doing things blindly I mean that in the past, all we could do was take one plant or animal that had traits we wanted and cross it with another planet or animal that had traits we wanted. The problem was that many traits don't breed 'true' and there could be genes that were 'hangers on' that might bring in traits we didn't want.

Now, if we want to breed for a particular trait, all we have to do is know what genes or combination of genes code for the appropriate protein.

The second issue, being able to cross the species barrier, I can understand a bit more but it still seems, to me, to rest on an essentialist view of living things. Even you say so below that you want a strawberry to only be a strawberry as if the insertion of a gene that makes a protein that prevents damage from freezing somehow makes it not a strawberry. The *only* reason why strawberries never hit on this neat little trick is that Nature never put that species in the position where the ability to resist extended cold was selected for. Plants have a different mechanism for surviving cold and, in the case of strawberries, it's called 'seeds'. But if strawberries had evolved in an environment where it was *always* cold (like under the ice pack) then they almost certainly would have hit on a similar trick. We are not, however, taking some essence of fish and putting it into a strawberry. We're simply taking a gene that, for reasons of historical contingency and evolutionary history, found itself in a fish and putting it in a strawberry where it does the same thing as it does in the fish. Nothing 'fishy' comes over because the protein *happens* to come from a fish, it isn't necessarily a protein that a fish and only a fish could ever have need of.

So why didn't the strawberry come up with anti-freeze on its own? Here I have to digress into evolutionary biology because it's the only way to make sense. I'm going to use two examples to explain evolutionary contingency, one real and one fanciful.

First the real:

The primate eye is actually built 'upside down'. What one would expect, if the eye had been designed by, say, an optical engineer that the light-sensing cells would be facing the source of light with all of the supporting infrastructure (blood vessels, etc.) behind the eye. That is not, in fact, how the primate eye is built. Instead, the light sensing cells are at the *back* of the eye and all the other structure of the eye is on top of it. This means that our eyes are less efficient then they otherwise could be. Now, if evolution could take steps backward the primate eye could have been rebuilt over evolutionary time so that it was more efficient (the eyes of cephalopods--squids and the like) are actually built the right way round. But evolution can't take back steps it can *only* work with what it already has.

The other example is the potential for human flight. The reason why we *can't* fly isn't that it is impossible for us to develop wings but that all of the things it would take for us to develop wings are simply not available to our species. Those pathways were closed off millions of years ago and there's no way to go back even though the ability to fly like bats would be mightily helpful to our species. Strawberries and fish haven't shared a common ancestor for hundreds of millions of years. The reason why the fish and the strawberry would never meet isn't that nature doesn't *want* them to but because there's no pathway by which they *could* meet. Not because there's something 'wrong' with it but simply because there's no selective benefit for either the fish or the strawberry to trade genes with one another.

Lastly, there's the issue of commonality of genes. While you look nothing like a banana you share 70% of all your genes with bananas. You are also not much like a fruit fly or a mouse (although you are, obviously, much more closely related to a mouse than a fruit fly) yet the very same gene that tells the developing human body "build eyes here" tells both the developing mouse or fruit fly to "build eyes here". To think about the implications of this try this thought experiment. If we took the gene, called 'eyeless', out of a human being and implanted it in a mouse what kind of eye do you think would grow? If you said "a human eyeball" you're wrong. It doesn't. The gene doesn't specify "grow this kind of eyeball here" instead it specifies "whatever kind of eye is appropriate for this species, it goes here". Do we know this to be true? Yes. How? Because we can and have taken that gene from a fruit fly, inserted it into the genome of a mouse where that gene had been 'knocked out' and pasted it in. Mice grew mice eyes where the gene specified it should. The same thing worked in reverse. A copy of the eyeless gene from a mouse, inserted into a fruit fly, caused the fruit-fly to grow a fruit-fly eye in the specified location.

Was there anything 'mouse-like' about the gene? No. In fact, there's a gene--the HOX gene--that specifies the body plan for almost everything living on the planet that *isn't* a bacteria.

DNA is DNA. There's no such thing as 'fish' DNA which is different from and incompatible with banana DNA. DNA either codes for a protein or tells another strand to start or stop.

I'm not saying we should go full-speed ahead with genetic engineering but I am saying that there is a lot of confusion and, in my mind, needless fear of the technology. I am not, let me be clear, defending Monsanto or any other agribusiness. I am talking solely about the scientific questions of genetic engineering.

At the end of the day, selective breeding and genetic engineering are the same kind of thing. Selective breeding is walking, genetic engineering is ballet.

Cheers
Aj

I do understand the science and technology behind it all Aj, I can even dig deep, and find a way to relate to how you feel about it.

For me, I want more of what I would be likely to find at the Portland Farmer's Market, and less of what I find primarily at places like Fred Meyers. Without going into my whole belief system here, I'll just say in other words, I'd like zero ballet, and a lot more walking when it comes to my food. Personally, I don't believe that because we can do something, means that we absolutely should do that something.

Maybe, just maybe, these pathways don't exist in nature, for a multitude of reasons.

On a side note...

I truly appreciate the thought and care that you put into your response. Though I don't agree with you in this instance (not about the facts you presented, just on how we use science and technology where food is concerned), I frequently do agree with you. On many occasions, you have brought up things that send me diving down a rabbit hole looking for more information, thus expanding my mind.