Glimpses Of Earliest Forms Of Life On Earth

Science Daily ^ | July 18, 2008

[Sopater]

“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.

Really... Well, I predict that scientists will study this bacteria through thousands, then millions, and eventually billions of generations, and in the end they will still be bacteria.

Someone mark the date that I made this bold prediction... 7/18/2008.

[Coyoteman]

Well, I predict that scientists will study this bacteria through thousands, then millions, and eventually billions of generations, and in the end they will still be bacteria.

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

[Sopater]

Are you trying to pretend that all bacteria are the same?

Certainly not. I'm simply stating that bacteria only reproduce bacteria.

[allmendream]

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?

[Soliton]

Really... Well, I predict that scientists will study this bacteria through thousands, then millions, and eventually billions of generations, and in the end they will still be bacteria.

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?

[Sopater]

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?

What I find amazing is how easily you are impressed with such weak evidence.

[allmendream]

In what way do you consider the evidence weak?

[Sopater]

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.

[Sopater]

How do you explain that the fossil record demonstrates an evolution from bacteria (prokaryotes) to more complex forms over billions of years?

I don't because it doesn't.

[allmendream]

No e.coli ever observed has the ability to digest citrate except the citrate plus strain that was observed to evolve in the lab. This is a complex metabolic pathway, the kind of increased complexity that many claim is impossible; now that it has been observed suddenly it is dismissed as not a big deal, but it is.

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.

[Sopater]

No e.coli ever observed has the ability to digest citrate except the citrate plus strain that was observed to evolve in the lab.

Tell that to this guy: Cloning and DNA Sequence of a Plasmid-Determined Citrate Utilization System in Escherichia coli

This is a complex metabolic pathway, the kind of increased complexity that many claim is impossible; now that it has been observed suddenly it is dismissed as not a big deal, but it is.

Actually, E.coli does have the ability to digest citrate. The only problem was that it can't get it into it's mouth. According to Lemski's article, he himself said:

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)

[Soliton]

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?

[allmendream]

The ability to digest citrate was cloned into the non citrate metabolizing e.coli by introducing plasmids that made the necessary enzymes.

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.

[Sopater]

The very next sentence says:

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.

You continue to amaze me.

[Sopater]

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?

[Soliton]

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?

[Coyoteman]

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."

[Sopater]

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."

It would be "catastrophic" for me... ;-)

However, how does an animal become "buried in sediment at the bottom of a body of water" without being consumed by other organisms? It has to happen by rapid burial by sediment.

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.

[allmendream]

Once again, it is the difference between acquiring a set of tools and making them yourself.

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?

[Coyoteman]

However, how does an animal become "buried in sediment at the bottom of a body of water" without being consumed by other organisms? It has to happen by rapid burial by sediment.

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).