theyeti

The idea that abiogenesis isn't falsifiable is pure baloney. How else could your creationist friend post info about the supposed impossiblity of abiogenesis if it weren't falsifiable? One of the more hilarious antics of the creationists is how they claim that evolution (or abiogenesis, etc.) can't be falsified right after a long-winded diatribe whose purpose is to try to falsify it!

What is true is that in the broad sense, the idea that living things came from non-living things via natural means can't be falsified without an exhaustive search through all possible mechanisms, which is something that we've come nowhere close to acheiving, and in fact may never acheive. This means that any attempt to prop up a theistic scenario based on proving abiogenesis impossible will be inadequate. But whose problem is that? Creationist arguments of this kind fail because they rely on the fallacy of bifurcation, and never on positive evidence for their own claims which could be judged independently. If a theory can't be upheld on its own merits, and instead relies entirely on attacking another one, it doesn't do much good to complain when the other one won't roll over and die.

More importantly, specific abiogenesis scenarios can indeed be falisified, and in fact quite a few of them have been rejected as new evidence has made them look unlikely. It is in this manner that we constantly improve our theories and make progress toward better understanding. Contrast this to a theistic explanation, which could never be falisfied regardless of how specific the scenario or how exhaustively one searches, and will never progress past "goddidit" which is pretty much useless even if true. At best, a theistic scenario, from a scientific standpoint, can be considered no worse off than any other scenario for which there is also no evidence. Without some specific testable claims, it will never be a legitimate scientific alternative.

***

As for the content of the atmosphere, the current consensus is that it was somewhere between neutral and weakly reducing. You still get amino acids and the like in a neutral atmosphere, just less of them. And there are other sources of prebiotic molecules, like comets and hydrothermal vents, that would have been opperating regardless of the atmophere's content. The consensus is strongly against any significant amounts of free oxygen in the primordial atmosphere -- there are a few researchers who advocate the idea, but there are good reasons to reject it. You might want to point out to your friend that if there had been significant amounts of oxygen, then the atmosphere would have been oxidizing, not neutral. It may sound like a nit-pick, but it's inconsistent to argue that the atmosphere was both neutral and oxidizing. This is demonstrative of the sort of "shot gun" approach that creationists take -- simply tossing out a laundry list of claims without regard to consistency.

theyeti

Albion

You might also want to ask your friend about the relevance of a neutral rather than reducing atmosphere to the conditions at deep-sea hydrothermal vents.

caravelair

he claims to have some proof the hydrothermal vents could not produce significant amounts of amino acids, but we haven't gotten into that part of the conversation yet.

Wounded King

Are we talking about the falsifiability of abiogenesis in general or the specific abiogenetic event giving rise to life on Earth? Assuming there was only one such of course.

caravelair

we have been discussing a great number of aspects of the theory. abiogenesis in general, as well as specific scenarios. i'm finding that abiogenesis far more difficult to defend than evolution, partly because i've never had to do it in such detail before.

how do i deal with the claim that geological evidence of the "primordial soup" should be found, and has not been. i'm thinking that it's not as likely to leave a record as has been claimed, but i really don't know.

also, i know that this is a very active field of research, so if anyone could point out some recent developments, it would be appreciated. thanks, all.

Oolon Colluphid

Well, a search of PubMed for ‘origins of life’ brings up 833 hits...
You can also try for ‘RNA world’ and similar.

Cheers, Oolon

theyeti

???

Why does he think that a geoloical record of such should be found? What's his reasoning behind this?

theyeti

Nic Tamzek

It sounds like Wells is the source behind this...so:

Wells FAQ, Miller-Urey section
http://www.talkorigins.org/faqs/wells/#Miller-Urey

NCSE Wells article, Miller-Urey section
http://www.ncseweb.org/icons/icon1millerurey.html

caravelair

i'll be sure to ask!

caravelair

actually, i believe that he is indeed a fan of wells. thank you for pointing out those articles.