Living Fossils

[randman]

Come on Jerry, the fact this bacteria hasn't changed in 3 biliion years pretty much blows evolutionist presumptions away as do other species exhibiting stasis.

Stasis is the opposite of what evolution predicted, and has not yet been adequately explained by evolutionists though some do try to deny its existence.

 

[npetreley]

Originally posted by Jerry Smith

Don't get angry Nick.

He don't know me vewy well, do he? Mad?!?! I'm having the time of my life. In fact, I really should be doing real work, but this is too much fun.

 

[npetreley]

Originally posted by randman
Come on Jerry, the fact this bacteria hasn't changed in 3 biliion years pretty much blows evolutionist presumptions away as do other species exhibiting stasis.

Stasis is the opposite of what evolution predicted, and has not yet been adequately explained by evolutionists though some do try to deny its existence.

When are you grade-school-educated creationists going to get it?

Speciation between mosquitos and mosquitos proves evolution.

Non-speciation between tigers and lions proves evolution.

Rapid change proves evolution.

Stasis proves evolution.

Stasis tells you that there's been little or no (or relatively constant, depending on the evolutionist) selective pressure, which proves evolution.

Lack of stasis and rapid changes in the fossil record tells you that selective pressure is not constant, but exploded at times, which proves evolution.

Genetic similarities between two creatures doesn't point to obvious similarities in their design, it proves they have a common ancestor, which proves evolution.

Generic similarities that you don't expect (I don't recall the example I read recently, but it was something on the order of man sharing some gene with bamboo that man doesn't share with chimps) do not disprove the rule. They simply point to another distant common ancestor between man and bamboo (or whatever it was), which also proves evolution.

The Bible plainly says we were created, but textual criticism says it came from multiple sources and changed over the years, which proves even the Bible evolves, which proves evolution.

Finally, in New Jersey, you drive on the parkway and park in the driveway, which also proves evolution.

So give up.

 

[Jerry Smith]

Originally posted by randman
Come on Jerry, the fact this bacteria hasn't changed in 3 biliion years pretty much blows evolutionist presumptions away as do other species exhibiting stasis.

Stasis is the opposite of what evolution predicted, and has not yet been adequately explained by evolutionists though some do try to deny its existence.

You forgot [rant] [/rant].

You are right that stasis is the lack of evolutionary effects. You are wrong in thinking common descent requires that evolution be constant for all species for all times. Think about what common descent and macroevolution mean. Think about what they are explaining and the theories at they are using for their explanations. Show me why those theories and explanations forbids the appearance of stasis over long times from occurring. When you have shown why the theories of common descent and evolution require that there never be any stasis, then I will feel obligated to provide an "explanation" adequate to answer the problem (not adequate to satisfy randman), and if unable to do so, will have to consider whether evolution has been falsified as a result.

 

[randman]

I never said evolution had to be at a constant rate, so don't interject an extreme straw man here.

What I do state is that stasis is the opposite of evolving, and when stasis occurs over millions and even billions of years, I have a hard time with the argument that conditions remained so much the same that there was no selective pressure.

Maybe for 100,000 years max, but not millions.

 

[Jerry Smith]

Originally posted by randman
I never said evolution had to be at a constant rate, so don't interject an extreme straw man here.

Ok, so lets see what you are saying...

What I do state is that stasis is the opposite of evolving, and when stasis occurs over millions and even billions of years, I have a hard time with the argument that conditions remained so much the same that there was no selective pressure.

If you have a hard time with that, maybe you could reconcile the apparent problem by asking yourself what would happen if in only certain lines of cyanobacteria (that did not go extinct, or did not give rise to other forms of life), there was selective pressure toward maintaining their simple and efficient forms and functions? In other words, could you ask yourself whether the environmental niche occupied by cyanobacteria could be a wide enough range of characteristics that there have been no changes to it that would impact cyanobacteria over the entire extent of their range?

 

[npetreley]

Originally posted by Jerry Smith

In other words, could you ask yourself whether the environmental niche occupied by cyanobacteria could be a wide enough range of characteristics that there have been no changes to it that would impact cyanobacteria over the entire extent of their range?

1. You're deliberately leaving out mutation and treating this as if only selection is involved. Hey, if you want to play "leave out the data" we can have some very stimulating volleys on who can be the most intellectually dishonest, but it won't have any content worth reading.

2. Speaking of which, by all means please argue that the enviornment has provided a nearly constant level of selective pressure on cyanobacteria for 3 billion years. The consequences of such an assertion would be marvellous to explore.

 

[chickenman]

of course you are forgetting that we can't actually measure the rate of mutation and genetic change between ancient and modern cyanobacteria, becuase we don't have the DNA of its precambrian forms. So you can't say that they are genetically identical, perhaps they are morphologically similar, but that does not preclude changes in their genomes.

 

[Jerry Smith]

Originally posted by npetreley

1. You're deliberately leaving out mutation and treating this as if only selection is involved. Hey, if you want to play "leave out the data" we can have some very stimulating volleys on who can be the most intellectually dishonest, but it won't have any content worth reading.

Ok, Nick, I will elaborate about the selective pressure so that you can see explicitly what it means in terms of mutations.

One individual or community of cyanobacteria may have a mutation. The mutation may or may not confer advantage for that individual or community that is makes it more fit for a certain range (narrower than the over-all range of cyanobacteria). If it does, we can expect the line stemming from this individual or population to diverge from the broader group of cyanobacteria.

Another possibility is that the mutation will be deleterious in its range (narrower than or coincident with the broader range of all cyanobacteria). If this is the case, this line will probably die out.

At the rate of reproduction of the cyanobacteria as a whole, we can always expect large populations that are non-mutant to continue in the broader range of cyanobacteria. Preserving the non-mutant line.

While it is unreasonable to expect no evidence at all of mutations having occurred an being preserved in the cyanobacteria adapted to the broad range, we can only expect the extinction of cyanobacteria that have only micro-evoloved if there is selective pressure of some kind making them unfit for survival in the broad range. As long as the basic cyanobacteria physiology is well suited to the environmental constraints of its own particular niche, and as long as its niche isn't drastically altered in a way that will impact the cyanobacteria's simple function, selective pressure does remain to keep cyanobacteria simple.

2. Speaking of which, by all means please argue that the enviornment has provided a nearly constant level of selective pressure on cyanobacteria for 3 billion years. The consequences of such an assertion would be marvellous to explore.

Levels have nothing to do with it. Selective pressures are environmental factors: they are conditions, not "levels of pressure". As long as there is water and light, there will be selective pressure on simple photosynthesizers to keep being simple photosynthesizers.

 

[Jerry Smith]

Originally posted by chickenman
of course you are forgetting that we can't actually measure the rate of mutation and genetic change between ancient and modern cyanobacteria, becuase we don't have the DNA of its precambrian forms.

We can measure "rate of mutation" in a lab, and we can see evidence that the genome of cyanobacteria has gone through some changes in the last 3 billion years by looking sequencing it and looking for tell-tale signs of mutations. I have little doubt that this has been done. Nick doesn't seem to understand how selective pressure can keep basic morphology and physiology relatively constant even in the presence of mutations.

 

[RufusAtticus]

For unicellular creatures, the morphology of sticky-outtie bits is less important for competition and survival than the biochemical pathways that influence innner stuff like metabolism and reproduction.

 

[npetreley]

Originally posted by Jerry Smith

One individual or community of cyanobacteria may have a mutation. The mutation may or may not confer advantage for that individual or community that is makes it more fit for a certain range (narrower than the over-all range of cyanobacteria). If it does, we can expect the line stemming from this individual or population to diverge from the broader group of cyanobacteria.

You can EXPECT nothing of the sort. If a mutation has an advantage (assuming that's even possible), what you can EXPECT is that you can't really EXPECT anything. It could die immediately due to competition with the more numerous ancestors. It could compete for resources with its prior generations and "starve them off" by being "more fit" to consume those resources. It could reproduce more than its ancestors. It could go to market and buy some roast beef. The fact is, you have no freakin' idea what to expect because there are so many other unknown factors.

Originally posted by Jerry Smith

At the rate of reproduction of the cyanobacteria as a whole, we can always expect large populations that are non-mutant to continue in the broader range of cyanobacteria. Preserving the non-mutant line.

First, once again you can EXPECT nothing of the sort. The fossil record is replete with examples of prolific forms of life that are today extinct.

Second, unless you're going to argue that cyanobacteria were created in the form the are today and were 3 billion years ago, the cyanobacteria are by definition mutants, themselves. In evolution, is no such thing as a non-mutant line.

Originally posted by Jerry Smith

As long as the basic cyanobacteria physiology is well suited to the environmental constraints of its own particular niche, and as long as its niche isn't drastically altered in a way that will impact the cyanobacteria's simple function, selective pressure does remain to keep cyanobacteria simple. ... As long as there is water and light, there will be selective pressure on simple photosynthesizers to keep being simple photosynthesizers.

You are implying that selective pressure is somehow magically preventing mutations from occurring, and that's pure unadulterated bullhockey. Selective pressure is what (theoretically) may contribute to a mutation being more or less successful, but it doesn't prevent the mutations from occurring. Yet we see no evidence whatsoever that mutations occurred, beneficial or not. The evidence just ain't there, and (according to your dating system) it has had 3 billion years worth of chances. Considering the reproduction rate of cyanobacteria, that's a lot of chance for evolution to occur. Yet while everything else was evolving into men, apes, and dolphins, the cyanobacteria just sat there and forgot to participate in this grand scheme, right? How logical.

 

[Jerry Smith]

snipping to interesting

Originally posted by npetreley
You are implying that selective pressure is somehow magically preventing mutations from occurring, and that's pure unadulterated bullhockey.

Nope. I'm implying that selective pressure is killing off varietys that deviate significantly from the successful line.

Selective pressure is what (theoretically) may contribute to a mutation being more or less successful, but it doesn't prevent the mutations from occurring.

You are right about one!

Yet we see no evidence whatsoever that mutations occurred, beneficial or not.

Where have you looked? Have you looked for psuedogenes in the genome of cyanobacteria for instance? If you haven't looked, you probably won't find.

The evidence just ain't there, and (according to your dating system) it has had 3 billion years worth of chances.

I have learned better than to take your word for evidence "not being there". You've called wolf too many times before.

[/quote]Considering the reproduction rate of cyanobacteria, that's a lot of chance for evolution to occur. Yet while everything else was evolving into men, apes, and dolphins, the cyanobacteria just sat there and forgot to participate in this grand scheme, right? How logical. [/QUOTE]

What would have occupied the Cyanobacteria's niche if Cyanobacteria hadn't been there?

 

[LiveFreeOrDie]

Originally posted by npetreley
You are implying that selective pressure is somehow magically preventing mutations from occurring, and that's pure unadulterated bullhockey. Selective pressure is what (theoretically) may contribute to a mutation being more or less successful, but it doesn't prevent the mutations from occurring.

You are making a fundamental mistake, Nick. Individuals mutate. Populations evolve. While it is indeed true that every individual organism is an inexact copy of its parents, that does not mean that the gene pool of the population as a whole changes significantly if at all. It's your typical bell curve behavior. Individuals may lie anywhere along the bell curve, but the genetic composition of the population as a whole may never drift far from the mean.

So while the individual cyanobacteria went mutating along, a stable selective environment kept the population's gene pool as a whole centered around the same mean.

Seeing as this is Rufus' area of expertise, maybe we should defer to him if you need an additional explanation.

 

[seebs]

It's actually pretty convincing to me to note that, while it's easy to discuss ways to outcompete feral cats (such as domestication), it's very hard for me to suggest a way to outcompete cyanobacteria... Suggesting that it's at a local maximum.