Meteorites Delivered The 'Seeds' Of Earth's Left-hand Life, Experts Argue is a Science Daily article peppered with a tale about space travel. The travelers were amino acids and the vehicles meteors. The crash landing may explain one of life's unusual features- chirality. As the author explains with rare exceptions "left-handed "L-amino acids" dominate on earth." A five to ten per cent excess in L-amino acids, observed on surfaces of meteorites, inspires confidence in this chirality explanation. Add some meteorite amino acids to the much famed primordial soup, cook in some desert like temperatures, add some water and presto- you get ingredients for a cell.

Given a spate of recent comments advising on the wisdom of doubting the religious persuasions of one's parents and even getting the parents themselves to indulge in this doubt-fest, I thought it might be a good opportunity for some to practice what they preach. After all most religions have an origins story to go with their value systems and other religious matters. Religious critics have their own origins story. Life emerged through tentative but unidentifed processes, formed an initial cell and evolved from there. So this is an opportunity for abiogenesis enthusiasts to weigh in with their own doubts. If you don't have them express them anyway. If doubting one's own religious convictions is healthy, doubting an origins story, which does not live up to its empirical billing, is healthier still.

A new analysis of the Martian rock that gave hints of water on the Red Planet — and, therefore, optimism about the prospect of life — now suggests the water was more likely a thick brine, far too salty to support life as we know it.

The finding, by scientists at Harvard University and Stony Brook University, is detailed this week in the journal Science.

"Liquid water is required by all species on Earth and we've assumed that water is the very least that would be necessary for life on Mars," says Nicholas J. Tosca, a postdoctoral researcher in Harvard's Department of Organismic and Evolutionary Biology. "However, to really assess Mars' habitability we need to consider the properties of its water. Not all of Earth's waters are able to support life, and the limits of terrestrial life are sharply defined by water's temperature, acidity, and salinity."

["¦.]

The water activity of pure water is 1.0, where all of its molecules are unaffected by dissolved solute and free to mediate biological processes. Terrestrial seawater has a water activity of 0.98. Decades of research, largely from the food industry, have shown that few known organisms can grow when water activity falls below 0.9, and very few can survive below 0.85.

Based on the chemical composition of salts that precipitated out of ancient Martian waters, Tosca and his colleagues project that the water activity of Martian water was at most 0.78 to 0.86, and quite possibly reaching below 0.5 as evaporation continued to concentrate the brines, making it an environment uninhabitable by terrestrial species.

"This doesn't rule out life forms of a type we've never encountered," Knoll says, "but life that could originate and persist in such a salty setting would require biochemistry distinct from any known among even the most robust halophiles on Earth."

The scientists say that the handful of terrestrial halophiles — species that can tolerate high salinity — descended from ancestors that first evolved in purer waters. Based on what we know about Earth, they say that it's difficult to imagine life arising in acidic, oxidizing brines like those inferred for ancient Mars.

-Here

Mike has highlighted the importance of proteins. Proteins are involved in all sorts of cellular functions including their own synthesis. Each step in the pathway to protein synthesis involves proteins. That includes the regulation of genes (whether or not a gene coding protein will be expressed), the transcription process and translation. It takes proteins to generate proteins. The proteins involved in the synthesis of other proteins are synthesized by the same cellular mechanisms they become part of.

There are two ways of analyzing the role of proteins. Proteins illustrate the interdependence of cellular functions and the dependence of cells on the proper coordination of its separate parts. That in turn is evidence of downward causation- a paradigm favorable to ID.

But we could continue to approach the matter of life's origin solely from a reductionist perspective. After all reductionism has led to success in other fields and provides an inductive argument for its continued utilization in origin of life research. Spinning wheels can keep an occupant in the same place but rabbits have another means of advancing.

Awhile back I offered what I considered to be an inductive argument for ID here:

http://telicthoughts.com/inductive-argument-for-id/#more-1609

Even though it wasn't an argument from ignorance, it was criticised as being such. Recently, MiKe Gene has brought up the topic of proteins here:

http://telicthoughts.com/an-amazing-design-material/

What I consider to be interesting is that we can make an inductive argument for ID in regards to proteins. First, let's review the form of an inductive argument:

(1) All known Bs are Cs.
(2) X is B.
(3) Therefore X is probably C.

There is an inherent weakness in any inductive argument: How do we know our sample of Bs is large enough to allow a valid inference to C? And the answer is: We never know. That doesn't stop us from using inductive arguments in order to draw probabilistic conclusions. What it means is that we should realize the weakness, and be cautious about our conclusions. With that in mind, here is the following argument: Read the rest of this entry »

From Robert Shapiro:

Since then, so-called prebiotic chemistry, which is of course falsely named, because we have no reason to believe that what they're doing would ever lead to life "” I just call it 'investigator influenced abiotic organic chemistry' "” has fallen into the same trap. In the proceedings of the National Academy of Sciences about two months ago there was a paper "” I think it was theoretical "” they showed that in certain hydro-thermal events, convection forces and other attractive forces, about which I am unable to comment, would serve to concentrate organic molecules, so that organic molecules would get much more concentrated in the bottom of this than they would in the ordinary ocean.

Very nice, perhaps it's a good place for the origin of life, and interesting finding, but then there was another commentary paper in the Proceedings by another invited commentator, who said, Great advance for RNA world because if you put nucleotides in, they'll be concentrated enough to form RNA; and if you put RNA in, the RNA will come together and form aggregates, giving you much more chance of forming a ribosome or whatever. I looked at the paper and thought, How did nucleotides come in? How did RNA come in? How did anything come in? The point is, you would take whatever mess prebiotic chemistry gives you and you would concentrate that mess so it's relevant to RNA or the origin of life "” it's all in the eye of the beholder. And almost all of prebiotic chemistry is like this; they take chemicals of their own selection.

People were talking about Steve Benner and his borate paper where he selected, of his own free will, the chemical formaldehyde, the chemical acid-aldehyde, and the mineral borate, and he decided to mix them together and got a product that he himself said was significant in leading to the origin of RNA world, and I, looking at the same thing, see only the hands of Steve Benner reaching to the shelf of organic chemicals, picking formaldehyde, and from another shelf, picking acidaldehyde, etc. Excluding them carefully. Picking a mineral which occurs only in selective places on the Earth and putting it in in heavy doses. And at the end getting a complex of ribose and borate, which by itself would be of no use for making RNA, because the borate loves to hold onto the ribose, and as long as it holds onto the ribose it can't be used to make RNA. If it lets go of the ribose, then the ribose becomes vulnerable to destruction by all the other environmental agents.

The half-life of pure ribose in solution, a different experiment and a very good one, by Stanley Miller is of the order of one or two hours, and all of the other sugars prominent in Earth biology have similar instability.

Prompted by a TT blog comment and being curious, I looked for a blog entry alleged to show how blogger Chu-Carroll had demonstrated David Berlinski's cluelessness. I came upon Berlinski's Bad Math, a commentary on Berlinski's article On the Origins of Life. I came away disappointed for rather than showing bad math on the part of Berlinski it instead demonstrated Berlinski's failure to hold to faith based outcomes believed to have occurred in a storied prebiotic setting in which putative self-replicating molecules replicated their way to living cells through unknown and unidentified chemical pathways. From the link:

Read the rest of this entry »

Abiogenesis and evolution are different topics. Evolution is supported by a massive amount of evidence and abiogenesis is not. Evolution has many well-established mechanisms while abiogenesis has nothing more than a myriad of speculations supported by slim amounts of circumstantial evidence. Evolution comes with a track record of success; abiogenesis does not. There is a Theory of Evolution; there is no Theory of Abiogenesis. Evolution is a core element of biology; abiogenesis is largely ignored. Since the two are not equally supported or understood, why treat them the same by reacting to a denial of abiogeneis as if it were a denial of evolution?

FREEMAN DYSON:
First of all I wanted to talk a bit about origin of life. To me the most interesting question in biology has always been how it all got started. That has been a hobby of mine. We're all equally ignorant, as far as I can see.That's why somebody like me can pretend to be an expert.

A LITTLE BUNNY:
The most significant unanswered question in biology is the origin of life. How did life first appear on this planet? Not only has this question escaped a non-teleological explanation for decades, it is the most crucial question in biology. The origin of life speaks to the essence of life, and that, in turn, builds context for the rest of biology, including evolution. All else follows from the initial states provided by the original cells and the context they set for subsequent evolution. In comparison, the rest of biology is a footnote.

I've finally posted my 50th entry in the Biotic Reality section of my web page. Enjoy.

A Scientific American article by Paul Davies entitled Are Aliens Among Us? raises some good origin of life issues. I'll focus only on the first page of the linked article in this blog entry and reserve the right to target the remainder of the article in the future.

Davies notes that the origin of life has remained resistent to scientific attempts to solve its mysteries. In fact we are unable to answer basic related questions such as how life originated and precisely when this happened. It is true that there is a consensus that puts the earthly figure at about three and a half billion years ago give or take a couple hundred million years. However, an absence of hard evidence does not lend encouragement.

Davies points out two schools of thought. Life could be the result of some extremely unlikely circumstances. So unlikely as to mean earth could be the only place in the universe where life is found. But alas there are many other universes some argue and this would change the implications of the odds existing in this particular universe.

Read the rest of this entry »