New Form of Life!

[stig]

I nearly had an orgasm when I read this. Enjoy.

http://dvice.com/archives/2010/12/nasa-discovers-2.php

http://blogs.discovermagazine.com/n...-using-arsenic-and-no-this-isnt-about-aliens/

 

[JoeJoe]

Reminds me of one episode of The Big Bang Theory.

*Sheldon is building a model of DNA.
Mrs Cooper: Oh, well that looks awful fancy, what is that?
Sheldon: It’s my idea of what DNA would look like in a silicon based life form.
Mrs Cooper: But intelligently designed by a creator, right?

HAHAHAHA!!!


Yeah, after that I always thought it's theoretically possible to replace one element with another of the same group.

 

[EvilScientist Trainee]

And i came thinking this was some sort of 'new me' thread.

But these articles are quite awesome. The arsenic just substitute the phosphate group of DNA, but does the bacteria itself has the same protein coding as other beings?

The ATP and glucose things were just outstanding. Being a health sciences major, that's something quite remarkable, thanks for the read.

 

[EvilScientist Trainee]

Yeah, after that I always thought it's theoretically possible to replace one element with another of the same group.

Indeed, that's one strategy to create new drugs, or stabilize those who got many adverse effects.

But the DNA has that important spatial structure, which is important in many of processes that are DNA-based. I thought that a larger radius atom would screw the structure, but that bacteria has coped with it very well.

Edit: Sorry for the double post.

 

[EyeSeeCold]

I nearly had an orgasm when I read this. Enjoy.

http://dvice.com/archives/2010/12/nasa-discovers-2.php

http://blogs.discovermagazine.com/n...-using-arsenic-and-no-this-isnt-about-aliens/

How did you completely miss the biology joke!? You should've said "organism".

 

[stig]

How did you completely miss the biology joke!? You should've said "organism".

I thought of it... after I posted.

 

[Wish]

Under the microscope, the bacteria become around 50% larger if they grow on arsenic compared to phosphorus, and they develop large internal compartments called vacuoles. These might be the key to their success. Wolfe-Simon thinks that the vacuoles could act as a safe haven for unstable arsenic-based molecules – they might contain chemicals that steady the molecules, and they might keep out water that would hasten their breakdown.

A bacteria that develops membrane-bound organelles? As I understood it, prokaryotes contain little else than their DNA, various plasmids and ribosomes, within the cytoplasm.

 

[stig]

A bacteria that develops membrane-bound organelles? As I understood it, prokaryotes contain little else than their DNA, various plasmids and ribosomes, within the cytoplasm.

Here's a good associated read.
http://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry

A quote pertaining to your quote, Wish:

Arsenic, which is chemically similar to phosphorus, while poisonous for most Earth life, is incorporated into the biochemistry of some organisms.[3] Some marine algae incorporate arsenic into complex organic molecules such as arsenosugars and arsenobetaines. Fungi and bacteria can produce volatile methylated arsenic compounds. Arsenate reduction and arsenite oxidation have been observed in microbes (Chrysiogenes arsenatis).[4] Additionally, some prokaryotes can use arsenate as a terminal electron acceptor during anaerobic growth and some can utilize arsenite as an electron donor to generate energy. It has been speculated that the earliest life on Earth may have used arsenic in place of phosphorus in the backbone of its DNA.[5] A new study released by NASA has revealed that a bacteria in Mono Lake, California may employ such 'arsenic DNA' when cultured without phosphorus.

 

[walfin]

This is really cool, maybe we can put the bacteria on some other planet and see what happens.

Amazing that even arsenic pollution can have beneficial side effects.

 

[OrionzRevenge]

A bacteria that develops membrane-bound organelles? As I understood it, prokaryotes contain little else than their DNA, various plasmids and ribosomes, within the cytoplasm.

Not too much of a stretch when you consider the Cynobacteria have a lineage of 3.5 billion years and they developed a completely differentiated cell type (scattered approx. 1 every 10 along a peal necklace-like colony) to 'fix' Nitrogen (The original bottleneck element) from the nearly inert atmospheric form.

This was waaaayyy before eukaryotes arrived on the stage of Earth Life.

 

[EvilScientist Trainee]

Orionz, sorry if I skipped the bacteriology classes, but how does is the communication between these cyanobacterias work?

In other words, are they a single organism or a group of microorganisms? (Because I didn't knew that kind of communication occurred).

 

[OrionzRevenge]

Yeah ES-T, You're gonna have to grab some Microbiology MoJo. It's a mindfuck every five minutes.

The CynoBacteria AKA: Blue-Green Algae, are just bacteria with photosynthetic compounds in the matrix. They divide along the longitudinal axis and the bi-lipid layers don't completely sever. So in effect, you have single cells finding an evolutionary advantage to living communally... 3 and a half BILLION years ago.

The obvious advantage derived by this arrangement was the ability for 1 out of every 10 or so cells to sacrifice its ability to 'be fruitful & multiply' in order to convert gaseous Nitrogen into Nitrates and Nitrites - to be released into the ambient aquatic environment in order to be taken up by hungry fellow cells in the colony.

I'm not sure of the actual trigger mechanism that tells the decimated members to differentiate into Nitrogen Nodules, but I'd almost be willing to bet the simplest is the actual. Thus, I would imagine starvation levels of NO2/NO3 in the solution IS the trigger.

Like a Queen Ant discovering that her colony has recently suffered a near-fatal invasion by noting the lack of solider ant scent on the female 'maids' that feed her and cart off her eggs to the nursery. Thus, the lack of this scent prompts her biology to lay soldier eggs till this scent is back to normal levels.

Or how a zygote knows where to put a leg or an arm by the concentration of signal 'scent' it smells.


I'm not a fan of the currently popular notions about the "Selfish Gene" POV or approach to evolution, and I see this as just another example of what I call Cooperative Evolution.

 

[walfin]

Sometimes I wonder if an alien species with a high degree of specialisation would look at us and think we are like cyanobacteria. Especially with all our valuing of individual freedoms etc.

I think given a choice, I would prefer to be cyanobacteria living in a bacteria colony, even "celibate" cyanobacteria that cannot reproduce, than a human red blood cell with its "brain" removed.

/irrelevant stuff

 

[Agent Intellect]

I'm not a fan of the currently popular notions about the "Selfish Gene" POV or approach to evolution, and I see this as just another example of what I call Cooperative Evolution.

Cooperation fits into the selfish gene paradigm. If being cooperative increases fitness, then the genes that promote cooperation will be selected for. Cooperation happens on the organismal level; selfishness is the gene(s) that promote cooperative behavior doing so in their own "self interest" (to be passed on to offspring due to surviving longer).

I think an interesting look at cooperation comes from colonies of Physarum polycephalum - a type of slime mold that act almost like a brain, in that it can solve problems and process information. It certainly has implications for the evolution of the brain.

 

[OrionzRevenge]

Cooperation fits into the selfish gene paradigm. If being cooperative increases fitness, then the genes that promote cooperation will be selected for. Cooperation happens on the organismal level; selfishness is the gene(s) that promote cooperative behavior doing so in their own "self interest" (to be passed on to offspring due to surviving longer).

I think an interesting look at cooperation comes from colonies of Physarum polycephalum - a type of slime mold that act almost like a brain, in that it can solve problems and process information. It certainly has implications for the evolution of the brain.

IMO

I agree when Richard Dawkins published his work in 1976 it offered a novel approach or POV towards the mechanics of selection. Yet, I fear the path it leads one down can lead to misinterpretation. Albeit Dawkins takes pains to point out the altruism his approach implies, I think that there is something intrinsically wrong with an approach that doesn't hold to Spock's Credo in ST2: "The good of the many out-weigh the good of the one."

In the example above, the 'Proto' Cynobacteria Nitrogen Nodules are sterile and can not have passed along this advantage. Thus, the adaptation was selected for species-wide.


http://en.wikipedia.org/wiki/The_Selfish_Gene

In the foreword to the book's 30th-anniversary edition, Dawkins said he "can readily see that [the book's title] might give an inadequate impression of its contents" and in retrospect thinks he should have taken Tom Maschler's advice and called the book The Immortal Gene

I also agree that Slime-Molds are Awesome!

 

[Agent Intellect]

In the example above, the 'Proto' Cynobacteria Nitrogen Nodules are sterile and can not have passed along this advantage. Thus, the adaptation was selected for species-wide.

The Cyanobacteria that have the ability to turn into nitrogen nodules could pass on the genes for this advantage. If there was a colony that had the mutation for such a transformation, and a colony that did not, when the conditions favored the change, the colony that has the mutation would survive and propagate while the one that doesn't would die off. Hence, the genes for nitrogen nodule transformation could be considered selfish by the selfish gene standards.

Some places where such a paradigm might break down is in horizontal gene transfer (which it could still apply to, if one considered that genes capable of this were selected for), endogenous retroviruses, and segregation distortion/sex-linked outlaws (when it comes to long-term survival).
http://en.wikipedia.org/wiki/The_Selfish_Gene

I also agree that Slime-Molds are Awesome!

Any complex dynamic network of organisms are awesome - what's more interesting, though, is that something like a slime mold is thought of as a mindless aggregate of cells. This is also what the brain is, yet cognition, emotion, and even consciousness can arise from the same basic principles as the communication of a colony of slime mold - molecules binding to receptor tyrosine kinases and g-protein coupled receptors. Even the cyanobacteria talked about above show specialization and differentiation within a colony (just like in an organ like the brain); the evolutionary implications are what's awesome!

 

[stig]

You know, enabled forum reps would be great right about now. OR and AI (AI? LOL).. I enjoyed your commentary immensely. Thanks for the informed contributions that I simply couldn't get through google.