How does cross- breeding plant species affect the integrity of the eco-system?

Question

About a year and a half ago I read in a book by, Clair Palmer

that many ecologists consider cross-breeding plants,

(i.e. broccoflower, grape tomatoes, etc.) hazardous to the integrity of the eco-system and it's biodiversity. Could someone please expound on this? Book or e-zine references

would be great also. Thanx.

Answer 1

If you introduce a hybrid plant into an environment where the original plants flourished, they will cross-breed and there could be unpredictable results. Clair Palmer questions the ethics of selective plant breeding in a similar way to the pro-life activists view on stem-cell research.

Answer 2

I disagree with the idea that cross breeding plants is hazardous to the environment.  At least with the two given examples, it isnt.  The only thing that could be bad would be if we bred an extremely invasive weed/vine or something and it was prolific.  

We are changing the appearance/dna of many types of plants through natural selection, we have been doing it for 1000's of years actually.  But does this really harm the ecosystem?  Most of the time, the original plants still remain in the world somewhere (example, corn came from breeding teosinte, but both plants still exist)...  Plus, most of the breeds we have created through natural selection wouldnt be able to exist in a natural environment without people in most cases.  So I say no harm done.

Answer 3

Cross-breeding is a specialty that nature (Gaia) seldom entertains.  The first example is the "mule", which cannot mate to have offspring.  It is the human-induced mating of a female horse with a male donkey.  Nature predominantly rejects cross-breeding.

When humans cross-breed other life forms, whether it is flora or fauna, it disrupts the natural exchange of genes.  Genetic mutations and natural limited cross-breeding do occur, and are controlled by success or failure criteria that either reward or penalize the new life form due to environmental and biological conditions.  But when humans cross-breed life, it is then protected by humans until it can be propagated, and that then changes the inter-relationships of all living forms in bio-diversity.  Anything out-of-place in the natural scheme of things either perishes or kills other life forms until it can find its niche.

There is a reason why every natural feature of life exists, and that is the key to survival that Charles Darwin and Cooke before him explained (Charles Darwin's grandfather, Erasmus Darwin, who died before Charles was born, was also an evolutionist).   The natural "acceptance" of change is based on successful interaction, such as, a three-legged horse would not be successful any more than a two-headed snake, although they might survive for some time.

When humans interfere with natural genetics that are quite successful, it disorganizes the natural success characteristics.  In foods such as corn and wheat, which are really grasses, humans have found that they can make supplies for consumption by modifying their genetics through "bio-engineering" called "hybridization", but those newly created "grains" cannot be consumed by the creatures (such as small birds) who had once depended upon them, and the counter-action to humans is that grasses cause cavities and diabetes in humans!

Similarly, human changes to bovine cattle have resulted in cow milk being a chief nourishment for humans, but cow milk is "designed" to produce thick bones in calves and an infant animal's growth from a human baby size to a 500 to 1000 pound animal in six months or so.  It is not natural for cows to provide milk incessantly year after year, as milking-cows do.  Worse, ranching cattle can destroy most of the ecosystem and cause erosion: though not as bad as sheep, as large heards they eat grass until there is no food for other animals, they trample stream banks which puts soil into the streams that kills fish, their meat is high in fat and cholesterol which is bad for human health, and human "husbandry" has led to larger cattle than is traditional.  By favoring certain animals, humans have killed off other animals because they were considered to be "less desireable", and yet, animals have a way of "symbiotically" assisting each other in ways unexpected, such as carnivores culling genetically weaker animals so they do not share their genes.

The food values to such fruit as tomatos, peaches, apples and vegetables exist because of certain reasons.  A watermellon is a great water source, but it only grows in sandy soils where there is ample water.  Humans can change such plants to perform their life functions in ways that may take a century or more to analyze.  We often do not know of the potential effects of changing the genetics of anything because results take so long to witness.

In hybridization, which is how corn and wheat came from grasses, people used the best of several same-genetic species to produce a different "superior" result, such as large thick kernals that grow vertically for six inches to a foot.  Natural "corn" was but a grassy "feather" of seed barely five inches tall.

But when mixing unlike species, the entire process is to create an organism that is no longer functional according to the organism's original success formula.  Hybrid corn uses a whole lot of water, for instance, much more than its original ancestor varieties.  Hybridization of the potato led to diseases the natural smaller potato did not suffer from, because the composition of the root became more watery and susceptible to fungi due to its genetic changes.  Plant disease can often spread to differing species when one plant is a host to a disease, such as the potato was.

Each organism has a biological "plan".  Trying to mix an abalone with a croccodile (pardon me for taking this from an actual joke out of the 1950s) to produce a "crock-a-baloney" is impossible, yet, mixing vegitable types to produce a different kind of food source can make a monster out of a plant that can kill off indigenous plants (tumbleweeds have killed indigenous grasses across the west as much as cattle have) and yet, if it will not survive as a "partner" in the eco-system, it will rob other plants of their nutrients and moisture.

As to food value to humans, certain fruits and vegitables and nuts have certain nutrients we need that other fruits and vegitables and nuts do not provide.  By mixing genetics, we have no idea if it will reduce the values we need, compromise the benefits or even over-produce nutrients we need so that they are too potent.  Toxicity is also a factor.  All of these conditions are "unknowns" even when laboratory analysis over several years finds no adverse affects: it can take a century or more to really see the result of cross-breeding.  It is best to stick with traditional foods that humans developed on: nuts, fruits, vegitables, and small game animals that are natural to the environment.