Posted on 07/18/2008 5:43:32 AM PDT by Soliton
Some bacterial cells can swim, morph into new forms and even become dangerously virulent - all without initial involvement of DNA. Yale University researchers describe July 18 in the journal Science how bacteria accomplish this amazing feat - and in doing so provide a glimpse of what the earliest forms of life on Earth may have looked like.
(Excerpt) Read more at sciencedaily.com ...
Life from non life ping!
Yes, now the new word is “morph.” We all descendantly, from these two meter backstoke bacteria, morphed into ourselves. LOL!
“We predicted that there would be an ancient ‘RNA city’ out there in the jungle, and we went out and found it,’’ Breaker said
Predictive ability of a theory is evidence that the theory is correct.
The RNA World (from 1974)
Virtually all biologists now agree that bacterial cells cannot form from nonliving chemicals in one step. If life arises from nonliving chemicals, there must be intermediate forms, “precellular life.” Of the various theories of precellular life, the most popular contender today is “the RNA world.”
RNA has the ability to act as both genes and enzymes. This property could offer a way around the “chicken-and-egg” problem. (Genes require enzymes; enzymes require genes.) Furthermore, RNA can be transcribed into DNA, in reverse of the normal process of transcription. These facts are reasons to consider that the RNA world could be the original pathway to cells. James Watson enthusiastically praises Sir Francis Crick for having suggested this possibility.
What the heck??? Where are the pictures of Adam and Eve?????
/s
RNA is still a complex compound, which has never been observed to form by inorganic means, AFAIK. Besides, even if RNA formed spontaneously, how would it suddenly become an enzyme? Enzymes are parts of the functional system of living cells. I.e. they are manufactured because they have a purpose. A “primordial soup” has no purpose.
If you are seeking truth, read this.
http://www.panspermia.org/rnaworld.htm
“An RNA-dependent RNA polymerase ribozyme is the foundation of the entire RNA World hypothesis,” Robertson said. “With that, you would have an RNA capable of making copies of itself; mutations or errors in some copies would result in variations that would be acted on by Darwinian natural selection, and the molecules would evolve into bigger and better ribozymes. That’s what makes this structure so interesting.”
There is nothing in the article but a variety of competing theories. No evidence at all. In fact, the focus of the article is that genetic molecules did not form by random processes on earth, but were seeded here from somewhere else...a concept which conveniently displaces the mystery to some extraterrestrial place. This not science, it is really just a new form of creation myth.
Indeed many of the protein enzymes we have still contain a small RNA section where the action happens.
I'm sorry that I didn't explain better. The article I asked you to read was to put the article I posted in perspective. ID/Creationist say that a cell is "irreducibly complex" and couldn't have evolved from less complex forms. Sir Francis Crick, who discovered DNA, predicted that if evolution was correct that RNA working as an enzyme could self replicate. This was one year before RNA enzymes were actually discovered. Since then there has been an hypothesis that before cells, there was an RNA world. The problem was that no one had found the right Ribozyme. That is what the article is about. They have found it! We have moved the evolution debate one major step forward to solving the life from non-life riddle.
Only two nucleotides? That only provides 16 combinations! It will be interesting to see the further levels of regulation that this entails.
A-A
A-U
A-G
A-C
U-A
U-U
U-G
U-C
G-A
G-U
G-G
G-C
C-A
C-U
C-G
C-A
WOW. Sixteen master keys that together can fit any riboswitch lock?
You can see why those who don’t understand think that design is necessary. It is elegantly simple, even beautiful.
Crick was right again.
Post 16...:-)
The time had come to ask how the DNA→ RNA→ protein flow of information had ever got started. Here, Francis was again far ahead of his time. In 1968 he argued that RNA must have been the first genetic molecule, further suggesting that RNA, besides acting as a template, might also act as an enzyme and, in so doing, catalyze its own self-replication.
Why did they have belly buttons and why did Adam have nipples?
I have no issue with design in and of itself; I am a Christian and do believe the laws of the universe were designed by God. I object to the suggestion of I.D. proponents (”cdesign proponentists”) that the universe was incompetently designed such that the mechanism in place for the evolution of life was a tool ill suited for the purpose and needs to constantly be superseded by miraculous intervention.
Are you trying to pretend that all bacteria are the same? What about this:
The Phyla of Bacteria (from Bergey's Manual of Systematic Bacteriology 1st ed.)
| Name of Phylum | Number of Species | Number of Genera |
| Aquificae | 27 | 12 |
| Xenobacteria | 29 | 11 |
| Chrysogenetes | 1 | 1 |
| Thermomicrobia | 13 | 6 |
| Cyanobacteria | 78 | 62 |
| Chlorobia | 17 | 6 |
| Proteobacteria | 1644 | 366 |
| Firmicutes | 2474 | 255 |
| Planctomycetes etc. | 13 | 5 |
| Spirochaetes | 92 | 13 |
| Fibrobacter | 5 | 3 |
| Bacteroids | 130 | 20 |
| Flavobacteria | 72 | 15 |
| Sphingobacteria | 76 | 22 |
| Fusobacteria | 29 | 6 |
| Verrucomicrobia | 5 | 2 |
Yes, and bacteria that previously didn’t have the metabolic pathway to digest citrate have been shown to be able to EVOLVE this capability. Pretty amazing that evolution stuff, no?
How do you explain that the fossil record demonstrates an evolution from bacteria (prokaryotes) to more complex forms over billions of years? Did creation take 3.5 billion years?
In what way do you consider the evidence weak?
I just don’t see variation within a baramin as strong evidence for the ToE. Especially when the “trait” that has been identified as a variation already exists in other similar species, and even in the same species. Call me when scientists have been able to observe a change such as bacteria reproducing a protist of some kind.
The rise of eukaryote was thought to take about a billion years, so if such was observed to happen in the lab over a few decades it would make us all rethink how evolution happens rather than being what one would expect.
Indeed such a rapid evolution is only proposed by Creationists who think all modern species were derived from a few pairs of animals loaded onto Noah's ark.
E. coli is not wholly indifferent to citrate. It uses a ferric dicitrate transport system for iron acquisition, although citrate does not enter the cell in this process (37, 38). It also has a complete tricarboxylic acid cycle, and can thus metabolize citrate internally during aerobic growth on other substrates (39). E. coli is able to ferment citrate under anoxic conditions if a cosubstrate is available for reducing power (40). The only known barrier to aerobic growth on citrate is its inability to transport citrate under oxic conditions (41–43).(emphasis added)
So your understanding of the fossil record isn’t that it starts with blue-green algae and increases over time to show the emergence of bacteria and protazoa and invertebrates and vertabrates and fish and amphibians and reptiles and mammals?
This is quite different than e.coli evolving the ability on its own. The difference between writing a new book and being given an already existing book to read. People said no “new book” could be written using evolutionary means, yet such has been demonstrated. The existence of a different book with the same “message” doesn't discount the fact that this was indeed a “new book” written by an evolving strain of e.coli; not an existing book given to e.coli by way of a plasmid.
From the paper....
The inability of Escherichia coli to utilize citrate as the sole carbon and energy source has been recognized for 60 years and provides the basis for an often-used distinction between Cit- E. coli and many similar but Cit+ bacterial species.
The recent discovery of naturally occurring plasmids that confer a Cit+ phenotype on E. coli strains (14, 15, 35) has provided an explanation for the periodic isolation of bacteria that would have been called E. coli except for their ability to utilize citrate.So the only reason that these other bacteria are NOT called "E. coli" is due to their ability to utilize citrate.
My understanding is that the fossil record is an historic record of catostrophy causing rapid burial of various organisms. Do you have a different understanding?
You would be correct only if you consider getting stuck and buried in mud or quicksand, or being buried in sediment at the bottom of a body of water, as "catastrophic."
Plasmids are often swapped between bacteria, and an e. coli may well come across a plasmid that has the enzymes to digest citrate (yet without the ability to absorb citrate it probably looses it just as fast); this is hardly the same as developing the ability on its own WITHOUT being given a plasmid. Do you understand the difference?
Even the mud or quicksand scenario is rarely likely to result in fossilization since creatures rarely die by submersion and are more likely to die on the surface due to starvation, dehydration, heat exhaustion, or attack by predatory animals. All resulting in eventually being consumed by other organisms.
Your examples are more the exception than the rule when it comes to fossilization.
Fossilization is rare for precisely this reason. The reasons you give are why forest floors and open environments are so poor at creating fossils.
However, becoming immersed in mud or quicksand is not that difficult to imagine for animals that fall into a pond or river. And its easy to see the nature of the sediment surrounding a fossil. For the vast majority of terrestrial fossils that's just what we get, silt and fine sand (ignoring volcanic deposits for the moment).
That's an artistic rendition. In actuality I have no idea what they really looked like or whether or not they had belly buttons.
You posted the picture. I thought you were trying to make a point. Sorry!
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