Has NASA Discovered Evidence for Extraterresterial Life?

[HeLiXe]

Arsenic-based life tastes like chicken, but I hear it's not good for you.

Arsenic based life is chicken non organic anyways

 

[HeLiXe]

Ivan Semaniuk made a good point in a sound bite.

He suggested it is not so much that this bacterium is making As-DNA, simply that As is getting substituted for P in the existing DNA.

Kind of like hemoglobin taking up CO instead of O, only more permanent (probably better examples of substitutions out there).

This is interesting.

 

[Orion1]

DNA substitutions...

Ivan Semaniuk made a good point in a sound bite.

He suggested it is not so much that this bacterium is making As-DNA, simply that As is getting substituted for P in the existing DNA.

If the bacterium strain GFAJ-1 of the Halomonadaceae family of Gammaproteobacteria is introduced into an environment that is Phosphorus poor and Arsenic rich and the As-DNA substitutions are the result of quantum chemistry, then if this strain is introduced into an environment that is Phosphorus poor and Nitrogen rich, then by quantum chemistry would the strain substitute Nitrogen for Phosphorus as N-DNA?

Similarly, if this strain is introduced into an environment that is Carbon poor and Boron rich, then by quantum chemistry would the strain substitute Boron for Carbon as B-DNA?

Definitely not, especially because Si-life would not be expected to function at the temperatures and pressures present on Earth. Furthermore, it's still not clear whether the organism actually functions using As-DNA instead of P-DNA.

There is the possibility that these substituted R-DNA strands are completely non-functional and inert molecules and completely incapable of transcription and replication.

 

[cronxeh]

So this announcement turned out to be somewhat boring. To me it was more along the lines of adaptation over a paradigm shift. Its nice to know that chemicals are relative to life, only the dynamics of evolution are essential in the long term.

 

[Orion1]

R-dna...

To me it was more along the lines of adaptation over a paradigm shift. Its nice to know that chemicals are relative to life, only the dynamics of evolution are essential in the long term.

If there is a paradigm shift in terms of quantum chemistry then the minimum qualification for R-DNA would include period 1,2,3 elements:
R-DNA (H,(B,C),N,O,P,S)

Then the maximum paradigm shift would include period 2,3,4 elements:
R-DNA (Li,Si,P,S,As,Se)

Including no paradigm shift to a complete paradigm shift, exactly how many different R-DNA substitution combinations are there?