From what I have read, it seems clear that certain "features" or traits have evolved in DNA multiple times/instances in the history of life here, which may indicate that the evolutionary paths may not be infinite. Also (and consequently?) we still do not know with certainty if the original life forms emerged from the early chemical soup in a single, rare instance, or multiple times in multiple places. There are strong indications that all life had a common origin (from DNA's own "fossil" history) but I don't think that we can be 100% sure. Living in the same 'brane as we do with Mars, the possibilities for life variations may likely be finite and even predictably similiar to what we (continue to) find here. Maybe we've also been microbially cross-pollinating each other's worlds for some time (meteoritic impacts, etc.) and just don't know it yet...?
At any rate, it seems like a Herculean (if not impossible) task to avoid the biologic "Heisenberg uncertainty principle" (observer effect) when looking for life on Mars, unless, as was pointed out, we find something radically different. --- Seth Jarvis <SJarvis@slco.org> wrote:
Supposing that a Martian sample return mission is successful, and we find simple microbes with DNA that is analogous to terrestrial DNA, the questions do indeed become profound.
Does this mean that DNA is "standard issue" for all life, or does it hint that Earth and Mars were both seeded (how? when?) by the same source (what?)
If a putative Martian microbe does _not_ have recognizable DNA yet is nonetheless self-replicating, then things really get interesting. Life establishes itself in multiple ways, not just through DNA. The sky's the limit.
Moreover, the new measure of the rareness of life shows that life occurs anywhere it can get a toehold. If it's on multiple places in just our own solar system, then how reasonable is it to believe that it isn't everywhere else?
Some religious folks will shrug and say, "Cool! God's use of DNA clearly works better than the moldy micro-life you get without His intervention."
Others religious folks will have a fit, but there's absolutely nothing we can do about it; it's the same fit they've thrown since the dawn of reason.
Seth
-----Original Message----- From:
utah-astronomy-bounces+sjarvis=slco.org@mailman.xmission.com
[mailto:utah-astronomy-bounces+sjarvis=slco.org@mailman.xmission.com]
On Behalf Of Chuck Hards Sent: Thursday, December 07, 2006 11:55 AM To: Utah Astronomy Subject: RE: [Utah-astronomy] (From NASA) Mars - RecentGushingWaterandNewCraters
I understand- it's the educator in you and you probably can't help yourself! No offense taken.
Now, keep your educator's hat on, go ahead and speculate a bit...
Assuming life on Mars is found, and further assume that it is clearly related to terrestrial DNA- what do you see as being the fallout in society?
--- Seth Jarvis <SJarvis@slco.org> wrote:
No condescension was intended,
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