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Naive questions (largely because this is a whole area of science I'm ignorant to, but I am curious): If plants could benefit from more efficient photosynthesis

Naive questions (largely because this is a whole area of science I'm ignorant to, but I am curious): If plants could benefit from more efficient photosynthesis, over the span of the billions of years they've been doing it, wouldn't they have evolved to do so? Sure, it may benefit us in some way to assist, but how does the plant benefit? The fact they're green and not other colors could be a significant evolutionary advantage... or wouldn't we expect to see other a large diversity of other colour plants? Why did green win out and not some other colour that absorbs different areas of the light spectrum? If one of the laws of nature is survival of the fittest, what do we humans know that makes us think that our ability to tinker with evolution without negative consequences is a wise decision?

mkaziz 11y ago
To your last point: Evolution is prone to local maximums. We evolved to think beyond them.
- astazangasta 11y ago
  You're talking about a "local maximum" sustained over half a billion years and trillions of organisms. It's much more likely that this is just optimal for plants.
  - balabaster 11y ago
    Exactly - if an infinite number of monkeys sat typing at an infinite number of typewriters, eventually, one would produce the entire works of Shakespeare...
  - oldmanjay 11y ago
    That's a logical fallacy on its face given the nature of evolution. If there is no pressure to improve then there is no reason for an improvement to take hold, but that in no way implies that a given mechanism is perfected along any access, just good enough.
murbard2 11y ago
The article gives at least one answer to that question: the over concentration of chlorophyll can be valuable when competing against other plant. This is a case where evolutionary fitness doesn't align with the goals of agriculture. This is one out of two typical answers which are 1) The fitness function is different, so there would be a trade-of but we don't mind it. 2) The biochemistry needed is very complicated, requiring many steps and is unlikely to be discovered by evolution.
- balabaster 11y ago
  If the plant doesn't use all the extra chlorophyll as the article suggests, then what purpose does it serve when competing against other plants. From what I gleaned from the article, this in my mind is akin to a track athlete having 50 pairs of shoes outperforming an athlete that only has 1. If the athlete can't use all 50 pairs of shoes at once, then what benefit do they offer? Can you clarify your interpretation of that statement because I don't get it.
  - murbard2 11y ago
    I didn't exactly get it either, because if they didn't absorb the photons with the extra chlorophyll, it's not like it would go to the other plants anyway... I just assumed there is a more complicated reason involving competition that the article didn't bother going into.
    - balabaster 11y ago
      So it didn't really answer the question...
      - deleted 11y ago
        [deleted]
      - murbard2 11y ago
        It hinted at an entire class of explanations.
Blahah 11y ago
There are two parts to the answer. Firstly, some plants have evolved to do photosynthesis more efficiently. One of the projects in the article (the one I work on) is to take a particularly efficient kind of naturally occurring photosynthesis - C4 photosynthesis - and copy it over to species that don't already have it. Sugarcane is an example of a plant with very efficient photosynthesis. Secondly, there are relatively few evolutionary innovations in photosynthesis for several reasons. The main one is that the global environment is constantly changing - the atmosphere is very different now than it was 1.6 billion years ago when photosynthesis first evolved. The atmosphere started out with no oxygen, so photosynthesis first evolved to handle that scenario. But photosynthesis releases oxygen by breaking up water molecules, so it gradually oxygenated the atmosphere and depleted the carbon dioxide. Modern conditions with very high oxygen and low carbon break a lot of the assumptions that were fixed into the early photosynthetic system, so improvements tend to be workarounds because evolution mainly builds on what is already there. The thing that humans have that evolution doesn't is the ability to reason about the system. Evolution is like an optimisation algorithm working within constraints, and humans are like software engineers that can change the constraints.
- Blahah 11y ago
  I forgot to add a second reason why there are few innovations in photosynthesis. In most ecosystems, photosynthesis is not the limiting factor. Other things like water, space, mineral nutrients and predation are more important, so there is no evolutionary pressure for photosynthesis to improve. But in agriculture we solve those problems - we provide space, water and nutrients, and we keep pests and competition away. Then photosynthesis becomes the limiting factor.
Sven7 11y ago
It isn't wise. Every time somebody figure's out how to optimize for one variable, everyone starts optimizing and we end up with great productivity for a brief bit and then the California drought. We have been lucky so far cause scaling up takes time.

mkaziz 11y ago

To your last point: Evolution is prone to local maximums. We evolved to think beyond them.

astazangasta 11y ago
You're talking about a "local maximum" sustained over half a billion years and trillions of organisms. It's much more likely that this is just optimal for plants.
- balabaster 11y ago
  Exactly - if an infinite number of monkeys sat typing at an infinite number of typewriters, eventually, one would produce the entire works of Shakespeare...
- oldmanjay 11y ago
  That's a logical fallacy on its face given the nature of evolution. If there is no pressure to improve then there is no reason for an improvement to take hold, but that in no way implies that a given mechanism is perfected along any access, just good enough.

murbard2 11y ago

The article gives at least one answer to that question: the over concentration of chlorophyll can be valuable when competing against other plant. This is a case where evolutionary fitness doesn't align with the goals of agriculture. This is one out of two typical answers which are 1) The fitness function is different, so there would be a trade-of but we don't mind it. 2) The biochemistry needed is very complicated, requiring many steps and is unlikely to be discovered by evolution.

balabaster 11y ago
If the plant doesn't use all the extra chlorophyll as the article suggests, then what purpose does it serve when competing against other plants. From what I gleaned from the article, this in my mind is akin to a track athlete having 50 pairs of shoes outperforming an athlete that only has 1. If the athlete can't use all 50 pairs of shoes at once, then what benefit do they offer? Can you clarify your interpretation of that statement because I don't get it.
- murbard2 11y ago
  I didn't exactly get it either, because if they didn't absorb the photons with the extra chlorophyll, it's not like it would go to the other plants anyway... I just assumed there is a more complicated reason involving competition that the article didn't bother going into.
  - balabaster 11y ago
    So it didn't really answer the question...
    - deleted 11y ago
      [deleted]
    - murbard2 11y ago
      It hinted at an entire class of explanations.

Blahah 11y ago

There are two parts to the answer. Firstly, some plants have evolved to do photosynthesis more efficiently. One of the projects in the article (the one I work on) is to take a particularly efficient kind of naturally occurring photosynthesis - C4 photosynthesis - and copy it over to species that don't already have it. Sugarcane is an example of a plant with very efficient photosynthesis. Secondly, there are relatively few evolutionary innovations in photosynthesis for several reasons. The main one is that the global environment is constantly changing - the atmosphere is very different now than it was 1.6 billion years ago when photosynthesis first evolved. The atmosphere started out with no oxygen, so photosynthesis first evolved to handle that scenario. But photosynthesis releases oxygen by breaking up water molecules, so it gradually oxygenated the atmosphere and depleted the carbon dioxide. Modern conditions with very high oxygen and low carbon break a lot of the assumptions that were fixed into the early photosynthetic system, so improvements tend to be workarounds because evolution mainly builds on what is already there. The thing that humans have that evolution doesn't is the ability to reason about the system. Evolution is like an optimisation algorithm working within constraints, and humans are like software engineers that can change the constraints.

Blahah 11y ago
I forgot to add a second reason why there are few innovations in photosynthesis. In most ecosystems, photosynthesis is not the limiting factor. Other things like water, space, mineral nutrients and predation are more important, so there is no evolutionary pressure for photosynthesis to improve. But in agriculture we solve those problems - we provide space, water and nutrients, and we keep pests and competition away. Then photosynthesis becomes the limiting factor.

Sven7 11y ago

It isn't wise. Every time somebody figure's out how to optimize for one variable, everyone starts optimizing and we end up with great productivity for a brief bit and then the California drought. We have been lucky so far cause scaling up takes time.