Naked Science Forum
Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: MarianaM on 09/09/2019 11:56:38
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Paul is wondering...
I plant some vegetables.
I go out into the garden a couple of weeks later and my garden is a mass of green......weeds!
I don't need to water or feed the weeds. They are very robust.
Have our vegetables been so inbred that they are genetically weak? Do our vegetables need to be crossbred with weeds to be more robust?
What are your thoughts?
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The weeds in your garden have had millions of years to evolve into your local ecosphere. They may have evolved all sorts of subtle interspecies dependancies and specific predator poisons that confer particular robustness and precise adaptation to the local soil. Fresh airborne seeds represent a continuous invasion force of millions that can tolerate 99.99% casualties, and the soilborne sleeper cells can lie dormant for thousands of years (people have grown wheat from grains found in the Pyramids) and tolerate massive and reversed climate change (healthy 500-year-old bromeliads found under retreating glaciers).
Compare this with your very few, very expensive single-species vegetables, inbred in the last 50 years for maximum yield in fairly nonspecific soils with no competition.
Essentially, you have planted a few untrained civilians in a country already occupied by dug-in native guerrillas and open to airborne assault by an unlimited, battle-hardened, multinational suicide squad, all intent on consuming the available nutrients.
Every edible potato is an improbable triumph of The Few. Hence the need for an alert and dedicated ground crew and defence regiment.
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Fruit & Vegetables are working under a severe disadvantage - most of their energy goes into producing stores of energy - for humans.
- Breeding has increased the percentage of their energy that goes into the edible parts
- For example, domesticated wheat, corn and pineapples have far larger edible parts than their "wild" relatives.
- They need human help to protect them from wild predators
The only reason that potatoes survive in the wild is that they live in such an inhospitable environment that it kills anything that doesn't have a good underground storehouse.
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We have chosen food because it was big, nutritious and tasty.
That is a very strong evolutionary pressure.
Nature has chosen weeds that are robust.
That too is a very strong evolutionary pressure.
Why would we expect that weeds would not be robust (any more than we would expect crops to be inedible)?