You are not logged in.
If we look at our ecosystem - it's one huge domestic war - organisms uses most of energy on competition, fight...
It's mainly energy from the cleanest, never ending source - the sun.
In the times of threat of energy crisis, overpopulation, one of our hope could be increasing the effectiveness of this changing solar energy into needed sugars, proteins.
The other thing is that we are geting closer to the concept of creating completely new ecosystems, like on Mars, where this effectiveness of development of ecosystem is essential for the whole project.
I would like to initiate a discussion about the possibility of such increase of effectiveness: is it possible and how much we could increase it?
One way I see to do it, is by selection of organisms - to create a very precise ecosystem, in which organisms almost haven't opposite interests.
We could replace some organisms with handicapped ones by eg removing sequences coding some proteins too(evolution couldn't repair it quickly) .
The tool we could use to remove some organisms, could be chiral life:
http://virology.wordpress.com/
Let say, we have this Noe's ark to select, modify ...
Let's think if it would be possible to such a stable, more effective ecosystem?
How to make it make it, so the proportion of organisms would be automatically keep on the appropriate levels?
So that evolution, climate differences wouldn't spoil everything...?[/url]
Offline
It is a curiosity that plants on Earth are green. This means that chlorophyll is scattering (rejecting) the green portion of the Sun's spectral light, and so plants appear green. But the green part of the Sun's spectrum is actually the most energetic part, so why do plants reject it? Is it too much for them? There is a "Purple Earth" theory which says that green plants evolved in competition with purple photosynthesisers which absorbed green and rejected red and blue light.
See: http://www.physorg.com/news95510352.html
Especially read the posted comment below about the chlorophyll molecule and its similarity to the hemoglobin molecule -- Mg versus Fe. Hemoglobin alternates red and blue in the transport of oxygen.
Hmmm. Maybe those early purple plants used something similar to hemoglobin for photosynthesis and then made the jump to animal life by eating their green competitors ....
In any event, Mars, being further out and very red, might do well with infrared absorptive plants, which might thus look violet-black (rejecting UV light).
[color=darkred][b]~~Bryan[/b][/color]
Offline
A further thought: plants on Earth with variegated leaves, like euonymous, self-regulate their light absorption. If you grow one of these in full sun, its leaves get lots of creamy-white patches, which is its way of reducing its light intake (it begins to reflect white light, which means the full spectrum is rejected). If you grow it in full shade, all the creaminess leaves the leaves (arghh) and they get dark, because the plant is trying to maximise absorption of the available energy. So it is actually a shade-loving plant which is nonetheless able to compensate for an overdose of sunshine by scaling back its own photosynthesis.
Plants on Mars should have broad leaves (to maximise exposure), with strong heliotropic powers (angling to the Sun) and dark dark chlorophyll (for maximum infrared absorption). The leaves should be thick and high in sugars to defend against cold and to retain moisture, with very small pores to reduce evaporation. Perhaps the plant will prepare for the night by folding down its leaves against the stem or trunk. No part of the plant should be brittle, because it must withstand dust storms and winds. It must have an aggressive root system to seek out moisture and it must be ready to "make hay while the sun shines". It might have tubers or bulbs deep underground for storing nutrients and reserve fluids. I think I have just described an uber-succulent for arctic conditions! A deciduous cactus perhaps.
[color=darkred][b]~~Bryan[/b][/color]
Offline
It's extremaly difficult to make corrections like "just exchange Fe with Mg" - it require almost completely new bichemical cycles, and adjust them to work perfecly... for a few hundret years we will base on Earth organisms.
But maybe we have on Earth placec with similar light spectrum like on Mars, or we could try to find these ancient organisms...
The reason of this thread was a bit different...
Any life we want to take there ... the best would be if it wouldn't be contaminated with unwanted things like viuses, microorganisms, etc. because they would reduce effectiveness of ecosystem we need...
Offline
I have to add that I thought mainly about eliminating (micro mainly) organisms that practically only parasitize, not contributing anything positive into the ecosystem, like eg viruses, locust ...
We couldn't restrict to system plants + us... soil have to be fertilized, fragments has to be decomposed, some reactions has to be made, plants has to be pollinate, etc, etc ...
We need trees too (oxygen), we have different environments, specifications of places...
Whereas most of the higher organisms in this moment, instead of farm animals, are rather keepsake of nature, they rather don't influence on our ecosystem...
The question eg is, if we can manage with that viruses helps control some populations...
Offline
It is a curiosity that plants on Earth are green. This means that chlorophyll is scattering (rejecting) the green portion of the Sun's spectral light, and so plants appear green. But the green part of the Sun's spectrum is actually the most energetic part, so why do plants reject it? Is it too much for them? There is a "Purple Earth" theory which says that green plants evolved in competition with purple photosynthesisers which absorbed green and rejected red and blue light.
Actually, it's not that simple. You get the most energy per photon from high frequency light, such as blue. You can do the most chemical work with blue.
Plants don't just use one pigment, or even just two. Photosystem 2 uses chlorophyll A and photosystem 1 uses chlorophyll B. (Numbers and letters are in order of discovery.) But plants also have other pigments that do more work, such as pumping hydrogen ions into a thylakoid for use in the by ATP synthase to make ATP.
However, upon a closer look you may be right. The absorption spectra of chlorophyll is remarkably opposite that of retinal, the photo-dye in halobacteria. Halobacteria are purple, salt-loving bacteria.
Offline
The required tool should be available in a few dozens of years (chiral life)
Let's focus on a possibility of eliminating some parasite...
What would it result in?
Here is the list of general parasites positive effect, I can think of...
Please expand it and discuss...
1. Population control - when the density of some organisms is growing, it's easier for its parasites to expand - this factor influence stability of the ecosystem.
The question is if without it, some specie could dominate its ecological niche?
Maybe it could be set that it would be automatically controlled by concurrency, food access,...?
Maybe such domination wouldn't be so bad?
Maybe without this control factor, ecosystem would achieve different point, which would be stable?
2. Stress increase - the elimination of weak organisms.
It improve selection, required to evolution. But after a few billions of years, a few thousand shouldn't be so important...
If it would be planned well, evolution shouldn't throw it out from the stable point...
Removing of weak organisms, makes place for new too, which probable would have positive influence on the effectiveness of ecosystem, but needs some energy to grow earlier.
So the removing of the parasite should make the population older, but I think that it wouldn't affect the effectiveness much...?
3. Stress increase - elimination of weak cells
Small amount of radiation can have positive results, perhaps because it helps to remove damaged (weaken) cells, thanks of what there should be smaller probability of cancer...
Summarizing - cells are being more frequent replaced - it's energetic cost, but thanks of it, organism should be more healthy and live longer...
So reduction of this stress among animals looks positive from our point of view (it increase selection of organisms too), but about people - energy isn't a priority - we should choose it as optimal as possible...
There should be many ways of replacing stress from infections.
We could eg use radiation - I think we should study this technique precisely.
I was thinking about using our immune system - teach him a very delicate autoimmune reaction, but it could be very dangerous.
Anyway we would have to give immune system something to do - living in the sterile environment can lead to autoimmune diseases (hygiene hypothesis).
Offline
1. Population control - when the density of some organisms is growing, it's easier for its parasites to expand - this factor influence stability of the ecosystem.
The question is if without it, some specie could dominate its ecological niche?
Maybe it could be set that it would be automatically controlled by concurrency, food access,...?
Maybe such domination wouldn't be so bad?
Maybe without this control factor, ecosystem would achieve different point, which would be stable?
If all else fails humans can control population of large plants with a little effort. In any event if left to itself a new equilibrium would develop, but it might be one we wouldn't like.
2. Stress increase - the elimination of weak organisms.
It improve selection, required to evolution. But after a few billions of years, a few thousand shouldn't be so important...
If it would be planned well, evolution shouldn't throw it out from the stable point...Removing of weak organisms, makes place for new too, which probable would have positive influence on the effectiveness of ecosystem, but needs some energy to grow earlier.
So the removing of the parasite should make the population older, but I think that it wouldn't affect the effectiveness much...?
Mars will be an island as well as a distinct environment from Earth. We'd want to let mutations and recessive genes be expressed. While we may need or want to make a few directed modifications nature would likely do a better job of molding existing genetics into the ideal form for Mars.
Offline
The problem is not with larg plants, but with all microrganisms...
About recessive genes - that could be not enough.
We may look for the solution in their introns - there should be some ancient mechanisms...
Anyway - the less parasites, the larger chance of success...
I have a serious discussion about this topic on
http://www.scienceforums.net/forum/show … hp?t=27078
Offline
SF writer, Greg Bear (http://www.gregbear.com/blog/display.cfm?id=982), pointed me out that we need viruses - the point is that we use some parts (eg capsid) of REV (retrovirus which is in our DNA) in some essential mechanisms, so we can't replace it to something neutral.
But over this millions of years, this capsids have been optimized for our purposes. Maybe it's good point for viruses to begin evolution, but there is still a long way, counted in thousands-millions of years. Viruses for evolution requires friendly environment - cells. Ours has quite good protection, much better then when viruses evolved last time.
We can also think about transforming only eg human, and use original bacterial flora, which could be compatible (after teaching the immune system)?
I've received a long letter from Steve Winter. One of many things he mentioned was that " there was a study where a group fed some bacteria chiral food, and it eventually evolved the ability to eat the food".
It's large problem, but I think they should have much more problems with evolution of interactions (like aggressiveness) with chiral organism, and in supported by us chiral ecosystem, they should be dominated...
And they usually die with the carrier.
But the largest benefit from chiral life are viruses - let's say that we can manage with microorganisms, but elimination of viruses looks hopeless
http://virology.wordpress.com/
And the lack of them should slow down the evolution of bacterias, making the creation of stable ecosystem easier.
What are the costs of such project?
The most of the cost is to transform a few cells of each needed specie - I think that required technology should be standard in a few dozens of years.
Then we have to replace seeds for a few fields, clone some cattle ... and humans for adoption...
The replacement process can be very slow.
And the income ... HEALTH ... crop production ... pests ... maybe to be or not to be for natural Martian life until terraforming
Offline
Hi Jarek, everyone.
I was hoping an ecologist would post a reply to your post but it doesn't look like that will happen so I will take a stab at it.
If we want the Martian ecology to take advantage of all the energy and physical resources avalible to it, competition IS very efficient.
We have not had much success with planned ecologies. Biosphere 2 was the biggest attempt and its ecology was so simple that it crashed. Many species overran the planned limits and humans had to become top level preditor, painstakingly squishing bugs for hours a day to try to keep things in ballance.
Having said that in general, I have some specific comments to things you said...
The sun is not never ending. It is building up Helium ash in its core and is slowly burning hotter. In around 800 million years we will have a run away green house effect and lose our oceans. (See "The Life and Death of Planet Earth" by P. D. Ward & D. Brownlee for the details of how the Earth's ecology & geochemic cycles will react to the increasing insolation.)
Even if we somehow set up a stable 'super efficient' ecosystem where there was little competition between lifeforms it won't last. Mars is a high radiation environment and any genetic drift will select for organisms that compete more efficiently than the handicapped critters we want.
Parasites are perhaps the ultimate in wasteful creatures but they are key in limiting populations that grow too dense allowing more variety in species. And variety is the key concept needed for viable ecosystems.
I think we would be better off selecting (and perhaps bioengineering) critters that are more tolerant of Martian conditions and let them create their own ecosystem.
Warm regards, Rick
Offline