Corwin

Let's see you do it then?

In THEORY you might eventually be able to select for the udder to be able to produce some sort of toxin, eventually. You would not, however, have a delivery system. Hence an organism that isn't 'venomous.' (Stomach acid is toxic if injected into the blood stream.... are we venomous?)

Again, random mutations are not part of selective breeding. (If you go into a selective breeding program with the intention of having a random mutation come along and give you exactly what you want, you're delusional and should be banned from such work. You might just as well pray for your desired result. It'll be just as effective.)

** edited to add **

Care to show me exactly where I'm 'wrong?'

Yeah I didn't think so.

Go back to the peanut gallery.

ps418

No. The irradiation does not simply kill bacteria, it mutates the crop DNA, producing new phenotypes that are then selected for breeding. Much of the food (thousands of different lines of plants) at your local supermarket has probably been created or modified by irradiation. Should these be banned from the US market, in your view?

Mutation techniques for plant breeding

Corwin

Yes.... along with the practice of doing cancer surgery with a husquavarna.

Mageth

In THEORY you might eventually be able to select for the udder to be able to produce some sort of toxin, eventually. You would not, however, have a delivery system. Hence an organism that isn't 'venomous.' (Stomach acid is toxic if injected into the blood stream.... are we venomous?)

Since a significant portion of the human population is lactose-intolerant, esp. as adults, and another (smaller) portion actually are allergic to cow's milk, one might say cow udders already produce a "toxin" for at least some humans.

So, hypothetically, the process may have been reversed. In human populations highly dependent on cow's milk, selection may have favored those who weren't susceptible to the "toxic" milk.

Again, random mutations are not part of selective breeding.

Really? Random mutations have no doubt been a part of selective breeding. Many of the beneficial crop enhancements that have occurred, and been selected for, over the centuries no doubt occurred due to mutations. A farmer notices that a particular potato plant produces particularly large tubers, or notices a corn plant which a common pest avoids (both due to mutations, though the farmer doesn't realize it), and selectively uses seeds from that plant to start next year's crop, and/or cross-pollenates that plant with other plants.

(If you go into a selective breeding program with the intention of having a random mutation come along and give you exactly what you want, you're delusional and should be banned from such work. You might just as well pray for your desired result. It'll be just as effective.)

No one said this was the process. All it takes is for a farmer to observe his crop (or flocks) and select particular plants (or animals) that exhibit desirable improvements.

ps418

Yes and no. It depends on what you mean by "part of." In any population of organisms there is genetic variation which has arisen through random mutation. Part of what breeding is is bringing together the desired mutations into a single individual or line of individuals. But you're doing it indirectly through the selection of phenotypes. There would be no point in breeding if there were no mutations around to select for.

Patrick

Corwin

And breed animals who exibhit those qualities to each other to strengthen the trait. This works especially well with recessives.

If a random mutation occurs, of course someone will take advantage of it. But it's amazingly rare and uncontrollable. You're just as likely to get a detrimental mutation as a beneficial one.

BioBeing

This is not entirely true. Useful applications of genetic engineering (retroviral therapy) are currently being used in the clinics. Limited numbers to be sure, but real clinical cases.

Mageth

If a random mutation occurs, of course someone will take advantage of it. But it's amazingly rare and uncontrollable. You're just as likely to get a detrimental mutation as a beneficial one.

Rare for one specimen, perhaps. But a farmer does not grow only one plant, and there is more than one farmer. If you extend it over thousands of farmers with crops reaching possibly millions of individual plants, then mutations will occur fairly often, both beneficial and detrimental. One farmer notices a mutation and selects for it. The improved plants could then be passed to neighboring farmers. The detrimental bit is a non-factor, anyways; you just select for the beneficial, and burn the detrimental to keep it from infecting your crop (another example of artificial selection/selective breeding).

And remember, the mutation may actually be detrimental in a wild population of the plant species, but beneficial to human use of the species, and thus artificially selected for. Or a mutation deemed detrimental by the farmer may be beneficial in a wild population, but loses its chance to be selected for because the farmer burns the plant or otherwise doesn't allow it to reproduce.

Actually, human selection may not be the only factor. A mutation could occur in a relatively small number of plants that allows those mutated plants to be even a little more resistant to a pest, though the farmer would not directly know this. The next infestation of that particular pest may decimate the rest of the crop and leave the remaining mutated plants, "naturally" selecting for that mutation.

ps418

To return to the OP, this article (PDF) makes the same point about the perceived dichotomy between natural and synthetic:

Patrick

Sr. Zonules

Thanks pat for your most recent post, that's the kind of thing I am looking for. :applause:

Corwin: First of all, I want to know what "pure" means. Surely a chicken is not purely pheasant. I also want to know how the mass diversity of life could come from just one type of being (prokaryotes), if you can't "add" any new traits. Last, I want to know (from YOU) what the difference is between "random" and "chaotic," and how the 2 are used when talking about pollen migration and natural genetic modification via the forces of evolution.

For y'all: Do you think that genetic modification will / can ever be fully understood and/or mastered by humans? and... what are key terms that people on both of the sides of the GMO debate completely mutilate? (e.g. random vs. chaotic) I believe this is one of the major problems of this debate.

-Z