Proof of Evolution?

[gipsy]

That's intelligent design

working with evolutionary principles ...

 

[Greg1234]

working with evolutionary principles ...

Evolutionary principles only show limited adaptation. http://www.christianforums.com/t7541198-16/#post56978429

 

[Wiccan_Child]

Evolutionary principles only show limited adaptation. http://www.christianforums.com/t7541198-16/#post56978429

There is nothing in the theory of evolution that places limits on how diverse life can become.

 

[gipsy]

Evolutionary principles only show limited adaptation. http://www.christianforums.com/t7541198-16/#post56978429

Depends on what you define as "limited" ...

 

[USincognito]

The problem with the "gill arch" fallacy is that the pharyngeal arches don't lead to any respiratory structures whatsoever....So anyone trying to defend evolution by citing vestigial structures and these recapitulated "gillslits" in the human embryo are doing exactly the same thing that they accuse the creationists of doing.....Changing the facts to suit their agenda....

The problem here is you're conflating a bunch of Creationist propaganda with outdated ideas.
1. Pharyngeal pouches do form gills in fish, but in terrestrial vertebrates they form a number of structures associated with the respiratory system including the eustachean tubes, and parts of the larynx.
http://en.wikipedia.org/wiki/Pharyngeal_pouch_(embryology)
2. Vestigial structures as understood by Creationists constitute a straw man. They aren't "useless" (they're reduced or changed in former function) and they aren't part of the long abandoned recapitulation hypothesis.
3. Recapitulation is long debunked, but again, the Creationist straw man of the debunking is wrong. Studies in embryology and evolutionary development show that certain embryo and fetal structures don't go through "previous stages" - ontology recapitulates phylogeny - but similar structures do develop from the same embryo and fetal parts and pieces. The proverbial pharyngeal arch is one example. Another is arm development in bats and mice. Haeckel was wrong, but less far off than Creationists claim.

If the fossil record does not show direct ancestry, why do so many evolution proponents act as if it does...

Another Creationist misconception. We don't need a single fossil to demonstrate common ancestry - at least since the 1950s and the discovery of DNA. Genomic and molecular comparisons of are more than enough to establish common ancestry of extant species. The fossils only help to "flesh out" the family tree and give some love to the extinct ones.

A logical question arises regarding whale ancestry: other organisms such as otters and crocodilians thrive in aquatic environments, but they have retained four limbs that are fully functional in both the land and the water...Why have these organisms not lost their hind limbs due to their aquatic habits?

It's always cute when Creationist apologists try and apply "logic" to scientific questions. Ironically though, you've chosen two poor examples. Otters and crocodilians are semi-aquatic. If anything, they haven't evolved back to a fully aquatic or marine reproductive cycle like Sirenians and Cetaceans to the ability to come back on land would be benificial no? And before you cite any other beings, amphibians have been successful for 300+ million years with such a reproductive strategy.

The only explanation off of the top of my head (and this truly is a wild guess, I am merely thinking practically) would be that since a whale has such greater mass than most fish, they would need greater support in the structures that provide locomotion, hence a bone structure more similar to a hand than a fin?

Odd you should cite locomotion because apart from lungs, mammary glands, etc., one of the indicators that whales are the descendants of fish who evolved into terrestrial tetrapods who eventually evolved back into dwellers in a marine environment is their method of locomotion. All fish swim side to side, but all terrestrial tetrapods move up and down. Guess what motion all aquatic mammals make when they move.

Pardon any unintended impertinence, but saying that most species don't fossilize seems awfully convenient for the evolution proponents...

It's not convenient, it's a simple fact. How many fossilzing bison or passenger pigeon skeletons do you find?

If all species we find are going to be at the terminus of a branch on the phyologenetic tree, then do we or can we really know for sure which organisms gave rise to which? If there are no examples of the organisms that are found at the bases of the branches, then how do we know that they were ever there to begin with?

See my comment above about genomic and molecular comparisons of extant species.

Why is the creationist idea that multiple generic "kinds" of animals were created, and then evolved--within their "kinds"--to show the diversity that we have today? Why is that creationism so invalid?

Because "kinds" is meaningless and it doesn't give a valid reason as to why a red fox and hyena or a white truffle and bakers yeast aren't related phylogenetically. The "kind" argument or the "limits of preloaded genome" (an ad hoc argument and not scientific anyway) amount to little more than a line in the sand drawn at high tide. Here's the test, take a step outside of the barnyard or zoo and pick, say, 15 beings at random. Then provide a scientifically viable explanation as to why they aren't related and show your work.

Would anyone consider this phylogenetic tree acceptable?

A shout out to Wiltor for not only showing why it's not acceptable, it doesn't reflect the reality of the taxonomy done since Linneaus. There simply is no comparison of any particular taxon that would exclude it from being included into another taxon lower than "life on earth".

 

[Jro]

Because "kinds" is meaningless and it doesn't give a valid reason as to why a red fox and hyena or a white truffle and bakers yeast aren't related phylogenetically. The "kind" argument or the "limits of preloaded genome" (an ad hoc argument and not scientific anyway) amount to little more than a line in the sand drawn at high tide. Here's the test, take a step outside of the barnyard or zoo and pick, say, 15 beings at random. Then provide a scientifically viable explanation as to why they aren't related and show your work.

Fencerguy, I'd be interested in hearing why you don't think 15 critters could be related as well.

 

[Fencerguy]

The problem here is you're conflating a bunch of Creationist propaganda with outdated ideas.
1. Pharyngeal pouches do form gills in fish, but in terrestrial vertebrates they form a number of structures associated with the respiratory system including the eustachean tubes, and parts of the larynx.
http://en.wikipedia.org/wiki/Pharyngeal_pouch_(embryology)
2. Vestigial structures as understood by Creationists constitute a straw man. They aren't "useless" (they're reduced or changed in former function) and they aren't part of the long abandoned recapitulation hypothesis.

never said they were useless.....

3. Recapitulation is long debunked, but again, the Creationist straw man of the debunking is wrong. Studies in embryology and evolutionary development show that certain embryo and fetal structures don't go through "previous stages" - ontology recapitulates phylogeny - but similar structures do develop from the same embryo and fetal parts and pieces. The proverbial pharyngeal arch is one example. Another is arm development in bats and mice. Haeckel was wrong, but less far off than Creationists claim.

How did my argument against recapitulation differ from what you have said......Here I notice you working off of your preconceived notions of what creationists believe...

Another Creationist misconception. We don't need a single fossil to demonstrate common ancestry - at least since the 1950s and the discovery of DNA. Genomic and molecular comparisons of are more than enough to establish common ancestry of extant species. The fossils only help to "flesh out" the family tree and give some love to the extinct ones.

interesting, you said common ancestry of extant species, there is no issue here; you have failed to address my arguement that a single common ancestor for all subsequent organisms lacks sufficient evidence to be valid. Of course extant species have common ancestry, but how common is that ancestry? I doubt that it all goes back to a single organism....
The reason that you don't need the fossil evidence is because you already believe that it is irrefutably true.....

It's always cute when Creationist apologists try and apply "logic" to scientific questions. Ironically though, you've chosen two poor examples. Otters and crocodilians are semi-aquatic. If anything, they haven't evolved back to a fully aquatic or marine reproductive cycle like Sirenians and Cetaceans to the ability to come back on land would be benificial no? And before you cite any other beings, amphibians have been successful for 300+ million years with such a reproductive strategy.

And it's always amusing to me when evolutionists try to talk down to me like some uneducated rube.....because they can't fathom that I might have a legitimate idea that might differ from theirs

Do you think that this guy would fit into the whale evolution chain?
So otters and crocodiles are forbidden from evolving any more aquatic features simply because they still reproduce on land......interesting logic....
Since penguins reproduce on land, why are their hind legs not better adapted to terrestrial behavior?

Odd you should cite locomotion because apart from lungs, mammary glands, etc., one of the indicators that whales are the descendants of fish who evolved into terrestrial tetrapods who eventually evolved back into dwellers in a marine environment is their method of locomotion. All fish swim side to side, but all terrestrial tetrapods move up and down. Guess what motion all aquatic mammals make when they move.

And? Locomotion seems to be a characteristic that they have in common, it does not necessarily mean that they are descendents....

It's not convenient, it's a simple fact. How many fossilzing bison or passenger pigeon skeletons do you find?

So if modern species aren't fossilizing, how did any previous species fossilize? wouldn't it make sense that some huge catastophe (even a global one) would lead to the burial of many many organisms that then became fossilized. And besides all that, if many more species do not successfully evolve new funcitonal stuctures, wouldnt there be many many more of those organisms in the fossil record?

See my comment above about genomic and molecular comparisons of extant species.

see my above comment about your above comment; just because you observe this about extant species does not mean that this principle is equally applicable to non-extant species......so any extrapolations are not scientific, since none of these studies can be done on the previous species........And this also fails to address why we wouldn't find any of the species that are at the bases of the phylogenetic branches....

Because "kinds" is meaningless and it doesn't give a valid reason as to why a red fox and hyena or a white truffle and bakers yeast aren't related phylogenetically. The "kind" argument or the "limits of preloaded genome" (an ad hoc argument and not scientific anyway) amount to little more than a line in the sand drawn at high tide. Here's the test, take a step outside of the barnyard or zoo and pick, say, 15 beings at random. Then provide a scientifically viable explanation as to why they aren't related and show your work.

First you will have to provide some definition for "related" because an evolutionist and creationist might differ on the connotation of "related"
And why do I have to prove that 15 random organisms aren't related?

A shout out to Wiltor for not only showing why it's not acceptable, it doesn't reflect the reality of the taxonomy done since Linneaus. There simply is no comparison of any particular taxon that would exclude it from being included into another taxon lower than "life on earth".

Umm, what? care to clarify why my phylogenetic tree is unacceptable?

 

[Hespera]

never said they were useless.....





irrefutably true.....

And it's always amusing to me when evolutionists try to talk down to me like some uneducated rube.....because they can't fathom that I
might have a legitimate idea that might differ from theirs

So otters and crocodiles are forbidden from evolving any more aquatic features simply because they still reproduce on land......interesting logic....

So if modern species aren't fossilizing, how did any previous species fossilize? wouldn't it make sense that some huge catastophe (even a global one) would lead to the burial of many many organisms that then became fossilized.

i trust you know I am on your side personally, but not, you know, argumentively..!

so let me give you some friendly advice.

evolutionists try to talk down to me

so dont set yourself up in some of the(amusing) ways that you do!

quit talking about "irrefutable". its tiresome nonsense.
quit using the term 'evolutionist". seriously. it stereotypes you in a way you dont really want

Now as to your questions...

So otters and crocodiles are forbidden from evolving any more aquatic features

Surely nobody said this. There is an extinct crocodile with a fish like tail and paddle like feet. Nobody can guess how far an animal might evolve.

So if modern species aren't fossilizing, how did any previous species fossilize

They are.

You do know that technically , all something has to do to be a fossil is to be buried. Bury your cat and dig it up quick and you have a living fossil!

All manner of things, organic and otherwise get buried. Some will be preserved, some wont. Anyone who has seen how a cow skeleton disintegrates in the pasture in a couple of years knows that skeletons dont necessarily get preserved, but a few do. And far far fewer are ever seen again.

Back to not sounding like a rube. Your question is really kind of for a knee high to ask. Instead of asking like you think its all nonsense, try doing some reading.

wouldn't it make sense that some huge catastophe (even a global one) would lead to the burial of many many organisms that then became fossilized.

No. flat out no. Paleontologists get really tired of this one. just no.
dont sound like a rube and you wont get talked down to.

Please?

 

[USincognito]

never said they were useless.....

I didn't say you said that and I'm sorry I phrased my response inelegantly. Let me clarify that particular response - The Creationist straw man is that evolution says vestigial structures are "useless", but it does not (at least since the 1800s). They are reduced or changed in former function.

Is that better?

How did my argument against recapitulation differ from what you have said

Umm, I was noting that you bothered, for some reason, to resurrect the long dead corpse of a debunked argument that isn't debunked for the reason most Creationists think it is and was pointing out that modern embryology and Evo-Devo provides a lot of evidence for evolution. Since recapitulation hasn't been offered as an evidence for evolution for 130+ years, I think the more germane question is why you brought it up at all?

Here I notice you working off of your preconceived notions of what creationists believe...

Pal, listen, I've been dealing with what Creationists believe since you were in grade school. That's not an appeal to authority or age or anything like that, so before you reply to this paragraph, please read and absorb the one above.

interesting, you said common ancestry of extant species, there is no issue here; you have failed to address my arguement that a single common ancestor for all subsequent organisms lacks sufficient evidence to be valid. Of course extant species have common ancestry, but how common is that ancestry? I doubt that it all goes back to a single organism....

Another cute effort at spin. Chew on this zen master. If genetic and molecular analysis can demonstrate common ancestry between, say, a human, chimpanzee, rabbit, chicken, tuna, lamprey, squid, sponge, etc. - all extant species - doesn't that axiomatically demonstrate common ancestry? If you want to check out all the sources demonstrating common ancestry for all Metazoans, check out this website.
Animals

The reason that you don't need the fossil evidence is because you already believe that it is irrefutably true.....

Hah...

Here I notice you working off of your preconceived notions of what creationists believe...

Irony meter explosion!

And it's always amusing to me when evolutionists try to talk down to me like some uneducated rube.....because they can't fathom that I might have a legitimate idea that might differ from theirs

Thinking your idea is legitimate is not the same as demonstrating it. Feel free to do so.

Do you think that this guy would fit into the whale evolution chain?

I don't know. You see the determination of where fossils belong phylogenetically isn't determined by a superficial representation, laymans opinions or gut feelings. They are determined by multivariate analyses of what often are minute differences in shape, form and function of the preserved bones. Provide me with the name of that fossil, I'll run it through Google Scholar, see what papers have been published on it and then I'll get back to you.

So otters and crocodiles are forbidden from evolving any more aquatic features simply because they still reproduce on land......interesting logic....

But pathetic straw man. I think my response above covered all the bases.

Since penguins reproduce on land, why are their hind legs not better adapted to terrestrial behavior?

Oh please, Creationists should never throw back these hypotheticals out. Why do terrestrial tetrapods have their trachea and esophogus in the same tube? Why do bipedal humans suffer from back problems? Why do blind cave fish develop failed eyes at all? Why do Cetaceans not have gills? Evolution explains all of these questions, but Creationism does not.

And? Locomotion seems to be a characteristic that they have in common, it does not necessarily mean that they are descendents....

Again with the myopia. If Cetaceans have the body motion - along with mammalian characteristics like viviparousness, mammary glands, lungs, endothermy, etc. etc., how could that not indicate common ancestry with other mammals that share those same characteristics? To suggest that God just made them to look exactly like mammals that evolved to live in marine environments is merely an ad hoc argument and not scientific.

- spilling the reply here.. see below.

 

[USincognito]

So if modern species aren't fossilizing, how did any previous species fossilize?

I didn't say that so you're beating up on a straw man. Try again.

wouldn't it make sense that some huge catastophe (even a global one) would lead to the burial of many many organisms that then became fossilized.

No. The vast majority of fossils are marine invertebrates. Limestone and chalk are little more than vast graveyards. Those fossils were created by simple sedimentation of the bodies of dead beings and sand, silt, etc. covering them.

And besides all that, if many more species do not successfully evolve new funcitonal stuctures, wouldnt there be many many more of those organisms in the fossil record?

No. Fossilization of non-marine organizims is rare. That's why I pointed out the American Bison and Passenger Pigeon. They are animals that lived in the millions for the former and hunted nearly to extinction for the former, and billions and hunted to extinction for the latter. Yet we don't see bones of either lying around St. Louis or Butte waiting to be fossilized.

see my above comment about your above comment; just because you observe this about extant species does not mean that this principle is equally applicable to non-extant species

See my above comment in response to your above comments. Your objection is untennable.

First you will have to provide some definition for "related" because an evolutionist and creationist might differ on the connotation of "related"

Please, don't act like that. You know exactly what I mean. Phylogenetic relationships established via the study of morphological, genetic and molecular characteristics - i.e. common ancestry.

And why do I have to prove that 15 random organisms aren't related?

Because all the evidence demonstrates that all life is related via common ancestry and it's up to you who advocate ICR's "orchard" of life so much that you post a graphic of it so show that the tree of life is falsified. It's one thing to post a hypothetical line drawing made by Creationist hacks, it's quite another to pick 15 beings at random and show how they aren't related.

Here's a tip, I posted a challenge for Creationists to tell me what "kind" 15 beings were, but none of them could do so and none had a response when I explaned why all of them were related via common ancestry. Perhaps you'll be the first.

Umm, what? care to clarify why my phylogenetic tree is unacceptable?

Because it's not a phylogenetic tree. It's a drawing you got from ICR with absolutely no supporting evidence. On the other hand, the Tree of Life Web is filled with supporting evidence. Here's the link for Metazoans again.
Animals

 

[Wiccan_Child]

interesting, you said common ancestry of extant species, there is no issue here; you have failed to address my arguement that a single common ancestor for all subsequent organisms lacks sufficient evidence to be valid. Of course extant species have common ancestry, but how common is that ancestry? I doubt that it all goes back to a single organism....

Nonetheless, the evidence is there. Do you at least accept that the theory of common descent could be true, in principle?

The reason that you don't need the fossil evidence is because you already believe that it is irrefutably true.....

As someone wise once said, the only thing needed to disprove evolution would be a fossil bunny in the pre-Cambrian.

No fossil exists before its time, so to speak. We never see humans in strata alongside dinosaurs, we never see birds in strata before dinosaurs, we never see whales before fish, etc.

And it's always amusing to me when evolutionists try to talk down to me like some uneducated rube.....because they can't fathom that I might have a legitimate idea that might differ from theirs

I'm sure I did nothing of the sort

 

[Fencerguy]

Nonetheless, the evidence is there. Do you at least accept that the theory of common descent could be true, in principle?

I accept that the theory of common descent is a legitimate hypothesis for the relationships that we see; but I don't agree with other's interpretation of the data.
My problem is that every observable and repeatable mechanism for evolution shows organisms becoming more specific and finely tuned for their specific environments; and all withing a specific type of organism....There aren't any observable mechanisms for organisms becoming new types of organisms (above the species level, which would be required for macroevolution). I haven't seen (or been shown as a result of inquiry) a plausible mechanism for the evolutionary changes that increase the complexity of a simple organism.
So my problem with the theory of common descent lies in this question:
At what point on the phylogenetic do the evolutionary changes shift from a tendency towards increased complexity, to a tendency towards speciation and genetic fine tuning? And what caused that change?

As someone wise once said, the only thing needed to disprove evolution would be a fossil bunny in the pre-Cambrian.

I would mention again things such as polystrate fossils and fossils of organisms that show up earlier than organisms they are supposedly descended from........The fossil record really only records the point in time that those individuals were buried and fossilized, they really don't give a good picture of what time period those animals actually lived it......I have heard several of you tell me that fossilization is a very rare process, so why do we assume that the strata of rock an organism is found in means that is the exact time period that that organism lived?

No fossil exists before its time, so to speak. We never see humans in strata alongside dinosaurs, we never see birds in strata before dinosaurs, we never see whales before fish, etc.

"...the widespread Lystrosaurus, hitherto regarded

as characteristic of the Lower Triassic,
cannot be used in isolation as a biostratigraphical
zone fossil ... The occurrence of​

Lystrosaurus in
Late Permian rocks indicates that isolated specimens
of the genus should no longer be used for
biostratigraphical purposes ... use of Lystrosaurus​

alone could be misleading. This is obviously unfortunate,
since​

Lystrosaurus is the most common
genus in many assemblages and so most likely to
be encountered in the course of stratigraphical​

work."
King, G.M. and Jenkins, I., The dicynodont Lystrosaurus from the Upper

Permian of Zambia: evolutionary and stratigraphical implications,​

Palaeontology 40(1):149–156, 1997.

I'm sure I did nothing of the sort

No, you have been uncommonly polite for the most part lol. UsIncognito dropped back into that realm of condescention for anything that hinted of creationism....lol

 

[Jro]

My problem is that every observable and repeatable mechanism for evolution shows organisms becoming more specific and finely tuned for their specific environments

Not true, we also see selection pressures for generalism and adaptability and the ability to make use of multiple or different environments.

There aren't any observable mechanisms for organisms becoming new types of organisms

This is not what evolution posits.

I haven't seen (or been shown as a result of inquiry) a plausible mechanism for the evolutionary changes that increase the complexity of a simple organism.

You need to define what you mean by complexity here, and I can reply to it more specifically. Evolution has shown an ability to produce complex, multi part structures on several occasions, and the mechanisms we know of have been enough to account for such occasions.

So my problem with the theory of common descent lies in this question:
At what point on the phylogenetic do the evolutionary changes shift from a tendency towards increased complexity, to a tendency towards speciation and genetic fine tuning? And what caused that change?

What do you mean by 'increased complexity' and 'speciation and genetic fine tuning'? Why do you think that's changed from something else? What do you think was happening before?

The fossil record really only records the point in time that those individuals were buried and fossilized, they really don't give a good picture of what time period those animals actually lived it......I have heard several of you tell me that fossilization is a very rare process, so why do we assume that the strata of rock an organism is found in means that is the exact time period that that organism lived?

Fossils can give us a good picture of an animal's ecology and environment. Many individual fossils are found within layers that have preserved many other specimens, giving us a good view of how the animal lived. We assume that an animal died in the strata it was found because that strata was formed by the same process that formed the fossil of the critter.

 

[Hupomone10]

I was browsing this and other creation/evolution threads and came across these.

Could someone tell me how they know one of these is a whale ancestor and one of them is an otter? There must be a tremendous difference between them that I'm not seeing...

 

[Fencerguy]

Not true, we also see selection pressures for generalism and adaptability and the ability to make use of multiple or different environments.

Then give me a mechanism for how organisms can acquire genes that they did not previously possess as part of their genetic code. Where did those new genes come from?

This is not what evolution posits.

Strange concept of evolution you have, the lowest layers of the phylogenetic tree require that the organisms changed on a larger scale than simply the species level....

You need to define what you mean by complexity here, and I can reply to it more specifically.

Show me a mechanism where a simple organism (say something of one or two or three cells) can acquire new genes that it did not previously possess, in order to change into a more complex organism, and then found a way to pass on those new genes in addition to the ones already contained in the organism's genetic code.

Evolution has shown an ability to produce complex, multi part structures on several occasions, and the mechanisms we know of have been enough to account for such occasions.

Then you are keeping those mechanisms very secret, because none that I have seen or been shown are sufficient for such large genetic and morphological changes....

What do you mean by 'increased complexity' and 'speciation and genetic fine tuning'?

Organisms at the lower levels of the phylogenetic tree show a tendency towards becoming more complex organisms. All observable mechanisms of evolution today demonstrate organisms becoming better suited to their niche, and increased fine tuning (including the loss of genetic information) in order to adapt to their environments.

Why do you think that's changed from something else? What do you think was happening before?

The phylogenetic tree makes me ask this question.......It is not a continual path from simple organisms to more and more complex organisms.....At some point, the evolutions went from adding genetic information to fine tuning and even eliminating genetic information...When or where did that happen?

Fossils can give us a good picture of an animal's ecology and environment. Many individual fossils are found within layers that have preserved many other specimens, giving us a good view of how the animal lived. We assume that an animal died in the strata it was found because that strata was formed by the same process that formed the fossil of the critter.

But none of this means that the organism lived only during the period that individuals of its species fossilized....

 

[Jro]

Then give me a mechanism for how organisms can acquire genes that they did not previously possess as part of their genetic code. Where did those new genes come from?

I've mentioned this to you before- mutation can add genetic data. This can come in the form of massive genome wide duplications. Wheat contains as many as six duplicates of its own genome. This inactive DNA is then free to mutate into something that does start to code for something new, without interrupting the function of the original DNA.

Strange concept of evolution you have, the lowest layers of the phylogenetic tree require that the organisms changed on a larger scale than simply the species level....

One individual organism does not change into another. Populations diverge to the point where they do not or cannot reproduce. They're new species then. Speciation is what leads to greater and greater divergence. But we don't work with 'types' of organisms.

Show me a mechanism where a simple organism (say something of one or two or three cells) can acquire new genes that it did not previously possess, in order to change into a more complex organism, and then found a way to pass on those new genes in addition to the ones already contained in the organism's genetic code.

Richard Lenski | Publications

Here's a great place to start.

Then you are keeping those mechanisms very secret, because none that I have seen or been shown are sufficient for such large genetic and morphological changes....

Nope, information is available for you if you want to look. Do some searches on 'phenotypic integration,' or 'ecomorphology,' heck, any really great study on the intersection of genetics and morphology. Would you define the criteria you give for 'large scale change'?

Organisms at the lower levels of the phylogenetic tree show a tendency towards becoming more complex organisms.

Not really, I mean, bacteria still exist in incredible numbers. We've seen more complex creatures arise, but it seems like we hit a plateau around fish. I mean, what makes us more complex than, say, a tuna? It's nice to have a brain and all, but they can fly through the ocean and move both their upper and lower jaw. That's pretty complex too!

All observable mechanisms of evolution today demonstrate organisms becoming better suited to their niche, and increased fine tuning (including the loss of genetic information) in order to adapt to their environments.

Well, yes, that is sort of what you would expect. This doesn't occur simply through the loss of information as you're positing though. How do you account for massive radiations of species, like the Rift Valley cichlids?

The phylogenetic tree makes me ask this question.......It is not a continual path from simple organisms to more and more complex organisms.....At some point, the evolutions went from adding genetic information to fine tuning and even eliminating genetic information...When or where did that happen?

You seem to have this thought in mind that evolution works with something besides fine tuning, and that new genetic information isn't being added now, or that new adaptations aren't happening now. They are. Things are chugging along fine.

But none of this means that the organism lived only during the period that individuals of its species fossilized....

Nope, but it's reasonable to say that it existed at that point in time and it becomes increasingly less likely that it existed at another point in time as we move farther away from its last evidenced position.

 

[Fencerguy]

I've mentioned this to you before- mutation can add genetic data. This can come in the form of massive genome wide duplications. Wheat contains as many as six duplicates of its own genome. This inactive DNA is then free to mutate into something that does start to code for something new, without interrupting the function of the original DNA.

I didn't say adding genetic data; I said the addition of new genes that the organism did not previously possess. An organism can replicate its DNA a hundred times, but it will still get all of the same genes that it had before. Even if a duplicated gene were to mutate and somehow allow that one-celled organism to become a two-celled organism; its still in a mutated gene that--by your own admission--doesn't interrupt the function of the original DNA.....

One individual organism does not change into another. Populations diverge to the point where they do not or cannot reproduce. They're new species then. Speciation is what leads to greater and greater divergence. But we don't work with 'types' of organisms.

then where did the first organism with an eye come from? There are far too many events and changes and structures that need to occur simultaneously in order to produce a functional eye (and not just a lump of tissue) for anything other than one or two generations of organisms with no eyes to have offspring that have eyes (even rudimentary ones).
By "types" of organisms, I mean ones like this; where the changes between them involve so much simultaneous mutation and change that they simply cannot gradually come about.

Richard Lenski | Publications

Here's a great place to start.

ok; I selected an article at random:
And here is something that I found quite interesting....At long last I have a mechanism for the introduction of new genes that the organisms did not previously possess!
"We allowed
some to have sex by introducing special genes
that let cells conjugate and recombine their genomes."

Nowhere else in this paper (or any other) is any other mechanism for acquisition of entirely new genes described. Why couldn't he have waited for the bacteria to acquire the genes that would allow conjugation on their own? They did reproduce so quickly.

Nope, information is available for you if you want to look. Do some searches on 'phenotypic integration,' or 'ecomorphology,' heck, any really great study on the intersection of genetics and morphology. Would you define the criteria you give for 'large scale change'?

I have looked, there is no specific mechanism that meets the sufficient criteria.....See my comment above for 'large scale change'

Not really, I mean, bacteria still exist in incredible numbers. We've seen more complex creatures arise, but it seems like we hit a plateau around fish. I mean, what makes us more complex than, say, a tuna? It's nice to have a brain and all, but they can fly through the ocean and move both their upper and lower jaw. That's pretty complex too!

My question is simply, why the plataeu? What caused the tendency towards complexity to level off (and in some cases reverse)?

Well, yes, that is sort of what you would expect. This doesn't occur simply through the loss of information as you're positing though. How do you account for massive radiations of species, like the Rift Valley cichlids?

No I realize that not every example of evolution today includes the loss of information, that was used as an example to differentiate between early evolution of simple organisms to what we observe now.......If genetic information is not lost, the changes are all within the organisms present genome...There is no longer any addition of exogenous DNA....

You seem to have this thought in mind that evolution works with something besides fine tuning, and that new genetic information isn't being added now, or that new adaptations aren't happening now. They are. Things are chugging along fine.

show me one organism today (or ever) that has managed to change by the acquisition and integration of completely new, exogenous DNA...

Nope, but it's reasonable to say that it existed at that point in time and it becomes increasingly less likely that it existed at another point in time as we move farther away from its last evidenced position.

ok, then don't speak in any more certain terms than that.......For all we know, just because dinosaur fossils predated humans by quite a while that doesn't mean that there weren't dinousaurs (of some kind) in existence when humans came around.....We can say its highly unlikely, but not that its impossible......If our consideration is based solely on the fossil record.

 

[Hupomone10]

all something has to do to be a fossil is to be buried. Bury your cat and dig it up quick and you have a living fossil!

I'm trying to just read the posts, for amusement (trying to stay awake for upcoming night shift). But some I just can't pass by.

First, a dead thing is not a living fossil.

Second,
Fossil: remnant, impression, or trace of an animal or plant of a past geologic age that has been preserved in the Earth’s crust.
fossil (paleontology) -- Britannica Online Encyclopedia

and using the favorite resource on this sub-forum:

"Fossils (from Latin fossus, literally "having been dug up") are the preserved remains or traces of animals (also known as zoolites), plants, and other organisms from the remote past.

"fossils range in age from the youngest at the start of the Holocene Epoch to the oldest from the Archean Eon several billion years old.

"The Holocene is a geological epoch which began 11,700 years ago
Fossil - Wikipedia, the free encyclopedia
Holocene - Wikipedia, the free encyclopedia

Your kitty cat is not a fossil.

Back to reading...

H.

 

[Jro]

I didn't say adding genetic data; I said the addition of new genes that the organism did not previously possess. An organism can replicate its DNA a hundred times, but it will still get all of the same genes that it had before. Even if a duplicated gene were to mutate and somehow allow that one-celled organism to become a two-celled organism; its still in a mutated gene that--by your own admission--doesn't interrupt the function of the original DNA.....

I linked you to a paper that demonstrated the acquisition of new genes conferring an ability to metabolise citric acid with the use of a new enzyme. These critters did not formerly possess this. What exactly are you looking for here?

then where did the first organism with an eye come from? There are far too many events and changes and structures that need to occur simultaneously in order to produce a functional eye (and not just a lump of tissue) for anything other than one or two generations of organisms with no eyes to have offspring that have eyes (even rudimentary ones).

A Pessimistic Estimate of the Time Required for an Eye to Evolve

We probably can't find the organism with the first eye. We can say 'the oldest organism we've found' and 'the most basal and rudimentary eye.' The evolution of the eye can proceed along discrete steps that improve the survivability for a critter along the way. This study shows a conservative model for the amount of time required to go from light spots to an eye. Many creatures have eyes of varyingly advanced stages through the animal kingdom. It turns out that you don't need to simultaneously evolve all that much to get some utility out of eyes.

By "types" of organisms, I mean ones like this; where the changes between them involve so much simultaneous mutation and change that they simply cannot gradually come about.

Evolution does not predict that such organisms will come about, except in exceedingly rare circumstances that are, as far as I know still theoretical. In general though, evolution is presumed to take a very gradual course that relies on forces like natural selection and genetic drift.

Nowhere else in this paper (or any other) is any other mechanism for acquisition of entirely new genes described. Why couldn't he have waited for the bacteria to acquire the genes that would allow conjugation on their own? They did reproduce so quickly.

Because he was studying the effects of sex on the evolution of bacteria. Read the paper on long term evolution of e. coli. They evolve the ability to metabolize citric acid with the use of the enzyme citrase.

http://www.pnas.org/content/105/23/7899.abstract

I have looked, there is no specific mechanism that meets the sufficient criteria.....See my comment above for 'large scale change'

Your criteria for large scale change is not something that is predicted to occur in evolution.

My question is simply, why the plataeu? What caused the tendency towards complexity to level off (and in some cases reverse)?

What's your unit of complexity?

No I realize that not every example of evolution today includes the loss of information, that was used as an example to differentiate between early evolution of simple organisms to what we observe now.......If genetic information is not lost, the changes are all within the organisms present genome...There is no longer any addition of exogenous DNA....

What are you talking about? Yes, DNA is added in some mutations.

show me one organism today (or ever) that has managed to change by the acquisition and integration of completely new, exogenous DNA...

Lenski, Lenski, Lenski.

ok, then don't speak in any more certain terms than that.......For all we know, just because dinosaur fossils predated humans by quite a while that doesn't mean that there weren't dinousaurs (of some kind) in existence when humans came around.....We can say its highly unlikely, but not that its impossible......If our consideration is based solely on the fossil record.

Yes, it's possible that dinosaurs existed with people and we haven't found the fossils in the same way that it's possible that unicorns, satyrs, dragons, etc., etc. are also scattered throughout earth's history and never fossilized. We have no reason to suspect that. Dinosaurs (of some kind) do continue to persist into this day and can probably be heard this morning.

 

[Wiccan_Child]

I accept that the theory of common descent is a legitimate hypothesis for the relationships that we see; but I don't agree with other's interpretation of the data.
My problem is that every observable and repeatable mechanism for evolution shows organisms becoming more specific and finely tuned for their specific environments; and all withing a specific type of organism....There aren't any observable mechanisms for organisms becoming new types of organisms (above the species level, which would be required for macroevolution). I haven't seen (or been shown as a result of inquiry) a plausible mechanism for the evolutionary changes that increase the complexity of a simple organism.

The new features arise generally by accident. Birds didn't grow wings to fly, they grew them to keep cool - much like elephants with large ears. Birds then found they had an enormous advantage when jumping between trees, a purely accidental side-effect. Once this took on, wings became far more valuable as jumping and gliding tools, rather than cooling devices - so evolution took off in another direction.

The bacterial flagellum, for instance, is a refinement of another structure - the 'hypodermic needle' of the bacterial world. While these were used for injecting toxins into cells, some bacteria found that they could also be used for limited locomotion. Those with finer control, at the expensive of some needles, had a distinct advantage over those drifting idly in water currents.

There was an experiment over 40 years that watched E. coli grow for 44,000 generations in various solutions, and one such vial of E. coli suddenly became very cloudy - they had evolved the ability to ingest the citric acid in their vial, and thus grow much more rapidly with this new foodstuff. This is a completely novel trait that other E. coli do not have. If they can evolve this new trait, and if old traits can mutate and change to fit their needs, who's to say this new feeding mechanism won't become the beginnings of E. coli multicellularity?

Basically, though organisms grow more specific for their ecological niche, there's nothing that prevents that niche from changing again, or for new niches to open up. Birds, for instance, evolved to fit their niche, but then found an enormous array of untapped niches - and they bloomed accordingly.

So my problem with the theory of common descent lies in this question:
At what point on the phylogenetic do the evolutionary changes shift from a tendency towards increased complexity, to a tendency towards speciation and genetic fine tuning? And what caused that change?

Usually, a change in the environment, or a new ecological niche that's been hitherto untapped. Cetaceans moving into the oceans, perhaps for more food or territory, suddenly found that they had far more food than was available on the shallow beaches - which is why it was selected for - and so moved into the oceans in droves. The same is true with birds in the trees, fish on land, etc.

Punctuated evolution has events that trigger rapid evolution, as opposed to static monotony, and these are generally new traits that evolved from old ones, such as a bird's flight or a bacterium's locomotion. Once this has occurred, these traits become massively more complex as there's a whole other selection pressure flexing its muscles.

I would mention again things such as polystrate fossils and fossils of organisms that show up earlier than organisms they are supposedly descended from........The fossil record really only records the point in time that those individuals were buried and fossilized, they really don't give a good picture of what time period those animals actually lived it......I have heard several of you tell me that fossilization is a very rare process, so why do we assume that the strata of rock an organism is found in means that is the exact time period that that organism lived?

Because when an organism dies, by and large it falls down on the topmost layer of soil and doesn't do much more than that. Rarely, it will stay there long enough for layers of rock and soil to sediment over it - so whatever layers we find it in, that generally corresponds to when it died. If it was found below the K-T boundary, then it died prior to the K-T extinction event. We can also use radiometric dating to test just how old it is, given certain constraints (C14 dating, for instance, only works for organisms that died about 50,000 years ago or less). There are a number of ways we can date fossils, and a number of other, independent ways we can date the strata they're found in. This site gives a good summary of those methods. By and large, we use radiometric dating to date the rock that forms the fossil itself.

"...the widespread Lystrosaurus, hitherto regarded

as characteristic of the Lower Triassic,
cannot be used in isolation as a biostratigraphical
zone fossil ... The occurrence of​

Lystrosaurus in
Late Permian rocks indicates that isolated specimens
of the genus should no longer be used for
biostratigraphical purposes ... use of Lystrosaurus​

alone could be misleading. This is obviously unfortunate,
since​

Lystrosaurus is the most common
genus in many assemblages and so most likely to
be encountered in the course of stratigraphical​

work."
King, G.M. and Jenkins, I., The dicynodont Lystrosaurus from the Upper

Permian of Zambia: evolutionary and stratigraphical implications,​

Palaeontology 40(1):149–156, 1997.

I don't see the relevance. Lystrosaurus is not forbidden from being found in the Late Permian by evolutoin. King is saying that, whereas before we thought Lystrosaurus was restricted to only the Lower Triassic where it is by far most abundant, he's warning paelaeontologists that it isn't only found in the Lower Triassic - there are some groups of Lystrosaurus that survived about 10 million years later into the Late Permian.

We still have a good picture of what Lystrosaurus did, though - we know it still is ubiquitous in Late Triassic strata, and some small pockets survived later on in time. We used evolution and dating methods to unearth this latter fact.

So, Lystrosaurus, while still the hallmark of the Late Triassic, lived later than we once thought in some geographic areas. I don't see the relevance, however - it's not like we're seeing mammals before fish, or birds before dinosaurs, something which evolution does forbid. Since mammals are a splinter group of reptiles (more or less, the details aren't too important here), we should never see mammals in strata lower than the first reptile. But seeing reptiles on par with mammals, that's no problem whatsoever.

No, you have been uncommonly polite for the most part lol. UsIncognito dropped back into that realm of condescention for anything that hinted of creationism....lol

I apologise for my cohorts, they can be... testy