Yes. Well, maybe. If the life is similar it could mean that life arises similarly independantly because life can arise in only so many ways. No way to know really. With such a small sample (two worlds) no definitive conclusions could be reached. You'd need a much bigger number of worlds to be able to draw that conclusion.
True, but I do think that there would be differences if life arose independently. Even on earth, convergence abounds (including
the molecular level), so clearly there are more than one ways to achieve certain functions - and there's considerable variation even in sequences that carry out the same function
and came from a common ancestor (like ribosomal RNAs). Not to mention the genetic code, which is pretty much arbitrary.
So even assuming that independently originated life on Mars invented the same nucleic acid-based heredity and protein-based metabolism using the same nucleotides and amino acids, I'd say there is some chance that we could tell whether they arose independently.
(Though if the common ancestor was far enough back - say, before the invention of the genetic code - then it would be much more problematic to distinguish between convergence and homology)
No, they don't Naraoia --- unless you're talking about some other microbes.
I was talking about microbes in general.
BTW, these
kinds of microbes are involved in the sulphur cycle on earth, and sulphur is, among other biological functions, a vital ingredient of proteins. Of
every single protein, in fact, because the synthesis of all proteins
begins with the addition of a
sulphur-containing amino acid... So you're not entirely right even there.
And honestly, would your reaction have been different if they found a new community of oxygen-producing or nitrogen-fixing bacteria?
(My main point wasn't that microbes are useful anyway - it was why on earth you posted in this thread if you're not interested in them.)
)
