Evolution: common ancestor?

[Resha Caner]

I am trying hard to understand what you are getting at so I am going to try from a somewhat different direction.

At this point I think that is going to require slow, careful, focused statements. My previous post was meant to start that focused conversation, but it seems you don't want to go that way. If not, I'm not sure I can give you an explanation, but I'll try.

Can you explain what you want scientists to change, how you want them to do things differently from what they are doing now?

I don't know that I'm asking biologists to change anything (in terms of definitions and methods). Only if they are missing what you're missing.

So what needs to happen first is to gain understanding between the two of us.

Disredux:
"The scientific definition of evolution is change in allie frequencies in a population over time. In other words, changes that are heritable and are involved in a population and not in individuals."

NAS:
"Evolution consists of changes in the heritable traits of a population of organisms as successive generations replace one another. It is populations of organisms that evolve, not individual organisms."

- - -

I see the NAS definition as a more rigorous version of the phrase "descent with modification". I see the NAS definition as having the ability to incorporate epigenetics into evolution if biologists agree to do that.

I don't see your definition that way.

If you don't see the differences, I'm not sure what you're thinking constitutes a justified change to a definition.

 

[AirPo]

Is it legitimate to say "3+2=5 is an example of addition"?
Is it legitimate to say "The definition has changed, and 3*2=6 is also an example of addition"?

But the definition hasn't changed. 3*2 = 6 is an example of addition. It's 2+2+2 = 6

 

[Loudmouth]

I did not. I said it would be fine to use that definition. My objection came when you said the definition might change. I am asking what justifies changing the definition.

1. No short definition is going toaccurately communicate everything that a massive theory is supposed to cover. If you want a fully accurate and all-encompassing definition then the definition is going to be hundreds of pages long.

2. Theories change over time.

I also, would like to get a feel for what you two consider to be moving the goal posts.

To use a specific example, let's say that someone gives us a good definition for "transitional fossil" that includes references to anatomical features. We then provide fossils that fit that description. We are then told by the person who defined "transitional fossil" that you can not use anatomical features to determine if a fossil is transitional. At one moment, the transitional nature of a fossil can be determined by anatomical features, and the next it can't. I would consider that as an example of moving the goal posts.

 

[Loudmouth]

I see the NAS definition as a more rigorous version of the phrase "descent with modification". I see the NAS definition as having the ability to incorporate epigenetics into evolution if biologists agree to do that.

I don't see your definition that way.

If you don't see the differences, I'm not sure what you're thinking constitutes a justified change to a definition.

No one or two sentence definition for the theory of evolution is ever going to accurately portray what the theory covers. That is the problem.

 

[Dizredux]

At this point I think that is going to require slow, careful, focused statements. My previous post was meant to start that focused conversation, but it seems you don't want to go that way. If not, I'm not sure I can give you an explanation, but I'll try.

I don't know that I'm asking biologists to change anything (in terms of definitions and methods). Only if they are missing what you're missing.

OK, so what am I missing? Since you seem to feel that scientists are getting it wrong, what is the field of evolutionary biology missing?

So what needs to happen first is to gain understanding between the two of us.

Ok but both Loudmouth and I seem to feel that you are objecting to scientific definitions and by implication, scientific theories changing as new evidence comes in. If we both see this then perhaps you also may have a problem communicating.

Disredux:
"The scientific definition of evolution is change in allie frequencies in a population over time. In other words, changes that are heritable and are involved in a population and not in individuals."

NAS:
"Evolution consists of changes in the heritable traits of a population of organisms as successive generations replace one another. It is populations of organisms that evolve, not individual organisms."

According to the current consensus on evolution, changes in the heritable traits of a population=changes in allele frequencies in a population. No real difference but that is subject to change as we learn more about epigenetics.

I see the NAS definition as a more rigorous version of the phrase "descent with modification". I see the NAS definition as having the ability to incorporate epigenetics into evolution if biologists agree to do that.

Could it be that you are trying to bring in epigenetics into evolution theory? In that case, you are right, the allele definition does not fit in that case. If that is what you are trying to establish then, I can finally see your point but if this does come to pass then the allele definition will simply need to change to accommodate the new information on epigenetics. No big deal really, just simple science.

Does this address your point? I sincerely hope so but I see no problems with changing definitions as needed based on new data. You seem to have a problem with this.

As an example, here are a couple of quotes from your posts to show why I have become confused about what you are trying to say.

"My objection came when you said the definition might change."

and

"Why is all this important? Because you keep bringing up the claim that no one has ever proposed a valid alternative to evolution. How can they if biologists are allowed to change the definition whenever they please and add any new discovery they please."

It seemed that your primary objection was to biologists changing when new data comes in and that is what I focused on.

Hopefully I am finally beginning to understand what your are after.

Dizredux

 

[Resha Caner]

OK, so what am I missing?

That's difficult to address when you keep clipping my answer to this question from your replies. I'm at a loss what to do, but I'll repeat it ... again. And this time I'll note the two issues as #1 and #2.

[edit] I'll note that I don't think you clip my answer to avoid the issue, but it's obvious that the point is not resonating with you since you seem to clip it out as something that's not relevant to your reply.

Could it be that you are trying to bring in epigenetics into evolution theory?

But first let me answer this. No, I am not trying to bring epigenetics into evolution. IIRC you were the first to mention it in this thread. My only point was that the NAS definition is properly worded such that biologists would be justified in doing that.

Issue #1: Do you understand the difference between your definition and the NAS definition? Your definition ties evolution to a specific mechanism (allele frequency). The NAS definition expresses a principle that includes that mechanism, but allows for others. To add epigenetics to your definition would be moving the goal posts. To add it to the NAS definition would not.

Issue #2: Under what circumstances do you think it is justified to change a definition? Your answers so far have been too vague.

No one or two sentence definition for the theory of evolution is ever going to accurately portray what the theory covers. That is the problem.

I understand that. If I had wanted to nitpick "descent with modification" I could have, but it would have been disingenuous. One can nitpick any definition if one doesn't want to accept it. My only concern, as I've said many times, is to avoid an exclusion problem. An honest assessment of descent with modification should conclude it does not cause that problem.

From that point forward, however, I do think it is necessary to understand the difference between definitions, mechanisms, measures, inductive/deductive logic, and conclusions. It's possible some of the things you think of as "evolution" fall under one of those headings rather than specifically under the definition of evolution.

 

[Dizredux]

Resha

I thought I was possibly getting closer to understanding what you are trying to say but apparently I failed again.

So I am going to make it simple. Can you explain for my weak mind:


What.is.the.point.you.are.trying.to.make?



That is the simplest I can approach the issue whatever it is.

Dizredux

 

[Resha Caner]

What.is.the.point.you.are.trying.to.make?

Issue #1 and Issue #2 as I marked them in post #126.

You thought one of my previous statements "high handed", so I'll just say I don't think a discussion between us on common ancestors will be productive until we get past this. From common ancestors, the discussion had moved somewhat toward alternative theories.

If you think I'm just being a jerk about the whole thing, that's unfortunate, but maybe it means it's time to end.

 

[Dizredux]

Resha Again, I am trying to figure out what you are trying to say.

Let me post some quotes that have me confused on what you are trying to accomplish

It gives an impression (true or not) that people are trying to claim every discovery in biology as evolution. I don't understand why you don't seem to see this.

Why is all this important? Because you keep bringing up the claim that no one has ever proposed a valid alternative to evolution. How can they if biologists are allowed to change the definition whenever they please and add any new discovery they please.

But such a definition excludes epigenetics. As such, if one finds epigenetics is a significant source of diversification in populations, one can't just arbitrarily pull epigenetics under the evolutionary umbrella.

So, the desire to keep pulling mechanisms under the evolutionary umbrella must have some other motivation. To say, "Well, because it's evolution," would be a logical fallacy - a circularity. If evolution is going to encompass both changes to the DNA and epigenetics, then the definition must somehow span both of them.

And the most confusing and I think most relevant:

My objection came when you said the definition might change.

What I see is that your primary issue is scientists keep changing the definitions and by implication the theory evolution when the data changes and you don't like this. You say it is not but, to me is clearly what you appear to be saying.

If it were just me getting this then it might be mostly my problem but here are some statements from Loudmouth:

I am trying to get a feel for what you consider "moving the goal posts". From what I have seen, you feel it is wrong for scientists to change a theory in light of new discoveries. Is this true?

It would seem that you expect scientists to keep evolution out of the their theory of evolution.

Your comment:

Why is all this important? Because you keep bringing up the claim that no one has ever proposed a valid alternative to evolution. How can they if biologists are allowed to change the definition whenever they please and add any new discovery they please.

Loudmouths response:

I find this view to be really confusing. Are you saying that scientists should not allow theories to change as new evidence is discovered? On one hand, you seem to criticize science for not considering new information, and yet you criticize science for changing theories because of new information.

I think the last one is especially relevant as that is the way I also see it.

Perhaps the problem is not in our misunderstanding but in your ability to make your point clear. It is something to consider.

As as a supporting point, the allele definition is not mine but is the consensus viewpoint of most biologists and geneticists. I have seen it stated too many times to consider it anything else.

The allele definition is more precise in that if specifically defines what changes are being measured. If you don't care for it, it is not a problem to me and we can use the one from NAS if you prefer. The thing is not to argue with me about it as I just report what I understand the consensus opinion of biologists to be. You can argue with them if you wish.



Dizredux

 

[Resha Caner]

What I see is that your primary issue is scientists keep changing the definitions and by implication the theory evolution when the data changes and you don't like this. You say it is not but, to me is clearly what you appear to be saying.

And yet you failed to include my statement from post #121 (something you previously responded to): "I see the NAS definition as having the ability to incorporate epigenetics into evolution if biologists agree to do that."

So, how can you say I object to associating new ideas and new information with a definition? What I object to is doing it without justification.

I also noticed you have declined to even acknowledge Issues #1 & #2 from post #126 (henceforward referred to as I1I2 because I'm getting tired of typing it out). If you will not acknowledge I1I2, this will never be resolved.

If it were just me getting this then it might be mostly my problem but here are some statements from Loudmouth:

Loudmouth and I have had ample opportunity to explore our differences. Regardless of who's fault it is, how about we keep this to an attempt to resolve our misunderstanding.

The allele definition is more precise in that if specifically defines what changes are being measured. (emphasis mine)

Exactly. Back in post #83 I called allele frequency a measure. As best I can tell, this is the first time you've noted that.

So, if someone asked, "What is time?" would you respond, "Time is seconds?" No. Seconds are the measure of time, not the definition. Further, I can measure that multiple ways. The ancients measured time with a pendulum. We measure it by the cycles of cesium. It wasn't wrong to incorporate the new measure, but rather it was more accurate ... and consistent with the principles of time.

... it is not a problem to me and we can use the one from NAS if you prefer.

OK. But I'm not sure it will be productive to go forward. Biology formalized itself later than other sciences like physics and chemistry ... I'm sometimes not sure it's even there now. Still, formalization is important if we're going to discuss common ancestors and alternative theories. Why?

Because what follows from definitions and axioms are the first principles of a science. Logic is then applied to those first principles to formulate conclusions - hypotheses. Those are tested and the evidence evaluated.

So, I'm OK with the colloquial statement that common ancestors is part of evolution, but in the most technical sense it is a conclusion. It is not part of the definition, is not a first principle. Evolution (the definition) could still be true even if common ancestry (one of the larger collection of things placed under the evolutionary umbrella) were false, and we need to be clear that the two are separable.

 

[bhsmte]

Resha Again, I am trying to figure out what you are trying to say.

Let me post some quotes that have me confused on what you are trying to accomplish

And the most confusing and I think most relevant: What I see is that your primary issue is scientists keep changing the definitions and by implication the theory evolution when the data changes and you don't like this. You say it is not but, to me is clearly what you appear to be saying.

If it were just me getting this then it might be mostly my problem but here are some statements from Loudmouth:

Your comment: Loudmouths response: I think the last one is especially relevant as that is the way I also see it.

Perhaps the problem is not in our misunderstanding but in your ability to make your point clear. It is something to consider.

As as a supporting point, the allele definition is not mine but is the consensus viewpoint of most biologists and geneticists. I have seen it stated too many times to consider it anything else.

The allele definition is more precise in that if specifically defines what changes are being measured. If you don't care for it, it is not a problem to me and we can use the one from NAS if you prefer. The thing is not to argue with me about it as I just report what I understand the consensus opinion of biologists to be. You can argue with them if you wish.



Dizredux

I think the main issue here is, Caner does not agree with evolution. When that is the case, you are much more prone to find things wrong with the same.

 

[Dizredux]

Originally Posted by Dizredux View Post

What I see is that your primary issue is scientists keep changing the definitions and by implication the theory evolution when the data changes and you don't like this. You say it is not but, to me is clearly what you appear to be saying.

Resha

And yet you failed to include my statement from post #121 (something you previously responded to): "I see the NAS definition as having the ability to incorporate epigenetics into evolution if biologists agree to do that."

I have already agreed to this if there is another evolutionary process involved that does not involve allele changes and at that point we would need another operational definition. What is the problem?

Resha

So, how can you say I object to associating new ideas and new information with a definition?

When I look at your comments, it is hard to come to another conclusion.

Resha

What I object to is doing it without justification.

OK then what would you consider to be adequate justification? This appears to be the primary issue.

Resha

I also noticed you have declined to even acknowledge Issues #1 & #2 from post #126 (henceforward referred to as I1I2 because I'm getting tired of typing it out). If you will not acknowledge I1I2, this will never be resolved.

Resha

Issue #1: Do you understand the difference between your definition and the NAS definition? Your definition ties evolution to a specific mechanism (allele frequency). The NAS definition expresses a principle that includes that mechanism, but allows for others. To add epigenetics to your definition would be moving the goal posts. To add it to the NAS definition would not.

I both acknowledged this and agreed as I noted above however it is not moving the goal posts, it would be simply adjusting to new information.


Resha

Issue #2: Under what circumstances do you think it is justified to change a definition? Your answers so far have been too vague.

Not mine to decide, I am neither a biologist nor a geneticist. This is a scientific issue and best left to scientists.

Diz

If it were just me getting this then it might be mostly my problem but here are some statements from Loudmouth:

Resha

Loudmouth and I have had ample opportunity to explore our differences. Regardless of who's fault it is, how about we keep this to an attempt to resolve our misunderstanding.

OK but the point is that we both see what you have been saying the same way.


Resha

The allele definition is more precise in that if specifically defines what changes are being measured. (emphasis mine)

Exactly. Back in post #83 I called allele frequency a measure. As best I can tell, this is the first time you've noted that.

You strenuously objected to this as an operational definition.

someone asked, "What is time?" would you respond, "Time is seconds?" No. Seconds are the measure of time, not the definition. Further, I can measure that multiple ways. The ancients measured time with a pendulum. We measure it by the cycles of cesium. It wasn't wrong to incorporate the new measure, but rather it was more accurate ... and consistent with the principles of time.

Errr OK?

Originally Posted by Dizredux View Post

t is not a problem to me and we can use the one from NAS if you prefer.

Resha

OK. But I'm not sure it will be productive to go forward. Biology formalized itself later than other sciences like physics and chemistry ... I'm sometimes not sure it's even there now. Still, formalization is important if we're going to discuss common ancestors and alternative theories. Why?

But that formalization is not set in granite and can change. That is a bedrock part of science, changing when new information becomes available.

Resha

what follows from definitions and axioms are the first principles of a science. Logic is then applied to those first principles to formulate conclusions - hypotheses. Those are tested and the evidence evaluated.

Errr OK again?

So, I'm OK with the colloquial statement that common ancestors is part of evolution, but in the most technical sense it is a conclusion. It is not part of the definition, is not a first principle. Evolution (the definition) could still be true even if common ancestry (one of the larger collection of things placed under the evolutionary umbrella) were false, and we need to be clear that the two are separable.

And descent with modification is a conclusion as well as common ancestry. It all, at least by the current view, stems from changes in the genetic makeup (allele frequencies) in a population over time.

Again, I do not see a problem with this but you apparently do but you don't seem to be able to articulate your objections at least to where my weak mind can understand it.

Perhaps I don't have the ability to understand what you are trying to say. If so, that is what it is.

Dizredux

 

[Kylie]

If you equate evidence with assumptions, then yes, there's plenty of that.

Actually, there's a lot of genetic evidence to support it.

 

[Dizredux]

I think the main issue here is, Caner does not agree with evolution. When that is the case, you are much more prone to find things wrong with the same.

I agree but he had some ideas that were at least interesting and not the same old pratts. I wanted to explore them a little but I could never get him to say what his point was.

Too bad, could have been an interesting conversation.

Dizredux

 

[Resha Caner]

Too bad, could have been an interesting conversation.

I'm an old war horse, so I don't have the energy for these discussions like I once did. But I'm sure someone else will eventually come along with basically the same ideas as me. Maybe you'll connect better with them.

 

[Loudmouth]

OK. But I'm not sure it will be productive to go forward. Biology formalized itself later than other sciences like physics and chemistry ... I'm sometimes not sure it's even there now. Still, formalization is important if we're going to discuss common ancestors and alternative theories. Why?

Because what follows from definitions and axioms are the first principles of a science. Logic is then applied to those first principles to formulate conclusions - hypotheses. Those are tested and the evidence evaluated.

The real problem is that you expect a curt definition for a very massive field of scientific study. You might as well ask for a one sentence definition of geology, and then get upset if it doesn't include your pet area of geology. Afterall, how can we falsify the theory of geology if it just incorporates all of the mechanisms of geology that we discover? One minute you are saying that water causes erosion, and the next minute you are saying that wind causes erosion. How can you have a falsifiable science if you switch between water and wind erosion, right?

You could go with the general definition of geology, that it is a field that studies the natural mechanisms that cause change in the Earth's weather, crust, and inner layers. However, I'm guessing you would throw this definition out since it is circular (which all definitions are, btw).

What you seem to misunderstand is that the overall theory of evolution is extremely overarching and general. The theory of evolution allows us to come up with multiple hypotheses and test them in specific cases. Is a specific speciation even due to sympatry or allopatry, or a combination of the two? How much of a role does natural selection play in the distribution of a specific allele in a specific species? How much of a species' genome is accumulating mutations at a rate consistent with neutral drift? We can use the theory of evolution to test all of these hypotheses.

So, I'm OK with the colloquial statement that common ancestors is part of evolution, but in the most technical sense it is a conclusion. It is not part of the definition, is not a first principle.

Very true. The theory of evolution never required a universal common ancestor. Even Darwin spoke of multiple origins.

In the same way, the theory of geology does not require there to be a Grand Canyon formed by the erosion from a river through slow uplift. However, that is what the evidence indicates, so that is what the theory of geology incorporates.

 

[Resha Caner]

The odd thing is, I thought this would be a small issue and we'd move on. I didn't expect it to derail the thread. But one does need to realize that when contentions arise, formality and rigor is the solution ... rigor to whatever level is necessary.

Since I have no leverage in the field of biology, there is a sense in which you can ignore me if this conversation is too much trouble. But if it's something you wish to pursue, then we have to formalize it to the level of rigor that will satify both sides.

Again, I thought I was only asking a small thing. If you look back at post #83 where this party started, I was saying it wasn't something I wanted to debate. I point that out to emphasize that I'm not trying to use this to disprove or discredit anything. I just wanted to be clear as the discussion moved into alternative theories.

The real problem is that you expect a curt definition for a very massive field of scientific study. You might as well ask for a one sentence definition of geology, and then get upset if it doesn't include your pet area of geology.

I didn't think I was asking for extreme precision in the definition. I was just asking what was in and what was out. From there I tried to point out that even if epigenetics is not explicitly mentioned in the definition, it is still a valid hypothesis (a potential conclusion) if the definition is properly worded.

Afterall, how can we falsify the theory of geology if it just incorporates all of the mechanisms of geology that we discover? One minute you are saying that water causes erosion, and the next minute you are saying that wind causes erosion. How can you have a falsifiable science if you switch between water and wind erosion, right?

Water and wind are two different mechanisms of erosion. As long as erosion is properly defined, it will allow for both - even if they aren't explicitly mentioned.

I am concerned, however, that you're equating geology to evolution rather than equating geology to biology. Is evolution just a synonym for biology? Even though erosion is a smaller theory in scope, I would expect erosion equates to evolution in terms of its classification as a theory ... though it sounds as if you might be saying evolution is not a theory but a field of study - a collection of theories. That's fine, but you would still need to articulate how one determines what is in and what is out.

You could go with the general definition of geology, that it is a field that studies the natural mechanisms that cause change in the Earth's weather, crust, and inner layers. However, I'm guessing you would throw this definition out since it is circular (which all definitions are, btw).

I understand. I wasn't trying to derail the thread with nitpicking. I was actually trying to do the opposite - lay a firm foundation for what I expected were going to be future misunderstandings.

What you seem to misunderstand is that the overall theory of evolution is extremely overarching and general.

Fine. But how do you decide what is "evolution"? You didn't claim erosion is a mechanism of biology, but of geology. Why? What do you use to distinguish the two? Is cell theory under the umbrella of evolution? I understand it might interact with evolutionary theory, but is it part of evolution? If not, how do you distinguish them?

You now have me wondering if evolution should be called a field of study rather than a theory.

 

[Loudmouth]

The odd thing is, I thought this would be a small issue and we'd move on.

Then why haven't you moved on?

I didn't expect it to derail the thread. But one does need to realize that when contentions arise, formality and rigor is the solution ... rigor to whatever level is necessary.[/qutoe]

The mistake you are making is in expecting a formal and rigorous definition of evolution in two sentences or less.

But if it's something you wish to pursue, then we have to formalize it to the level of rigor that will satify both sides.

We could start here:

http://www.textbooks.com/BooksDescr...DREPLACE-291&gclid=CMLe6MjsuL4CFUOFOgodEDsAjQ

Futuyma's "Evolution" is one of the more respected textbooks, but even that textbook is not going to cover all of the information in a rigorous or formal matter. For any specific example you want to talk about, we also need to include the last 20 years of primary research that has been done on that specific topic alone, be it the divergence of South American butterfly genera or epigenetics. Only then would I be satisfied that we have something solid to even begin a rigorous and formal conversation on evolution.

What are your requirements? I would hope that it is more than a paragraph.

I didn't think I was asking for extreme precision in the definition. I was just asking what was in and what was out.

So often, you say one thing in one sentence, and then the exact opposite in the very next sentence. This is a good example.

Water and wind are two different mechanisms of erosion. As long as erosion is properly defined, it will allow for both - even if they aren't explicitly mentioned.

Wouldn't that be circular?

I am concerned, however, that you're equating geology to evolution rather than equating geology to biology.

Geology is how the Earth changed over time.

Evolution is how species changed over time.

I view them as kissing cousins.

Is evolution just a synonym for biology?

For the most part, yes. Everything else is just stamp collecting.

To use a geologic analogy, you can measure the ratio of minerals, size of crystals, and isotopic age of a rock. That is all stamp collecting. Geology is understanding that rock in the large context of the formation it came from and the history of that formation. The exact same for evolution. Measuring the number of phalanges, genome sequences, and geographic distribution of species is just stamp collecting (although important stamp collecting). Biology is about putting that evidence into context, and the only way that happens is through the lens of evolution. Evolution is to life what geology is to the Earth.

Even though erosion is a smaller theory in scope, I would expect erosion equates to evolution in terms of its classification as a theory ... though it sounds as if you might be saying evolution is not a theory but a field of study - a collection of theories. That's fine, but you would still need to articulate how one determines what is in and what is out.

You determine what is in or out by whether or not there is evidence that the proposed mechanism causes heritable change in species.

Fine. But how do you decide what is "evolution"?

The same way we decide what is geology. Mechanisms that change the Earth over time are part of geology. Mechanisms that change life over time are part of evolution.

 

[Resha Caner]

"Is evolution just a synonym for biology?"
For the most part, yes. Everything else is just stamp collecting.

Hmm. I didn't think biology was all about heritable changes. Does that mean abiogenesis is not part of biology or that it is part of evolution?

The mistake you are making is in expecting a formal and rigorous definition of evolution in two sentences or less.

I don't recall specifying a length. Take as much time and space as necessary.

Then why haven't you moved on?

I'm more than ready to move on.

 

[Loudmouth]

Hmm. I didn't think biology was all about heritable changes.

"Nothing in Biology Makes Sense Except in the Light of Evolution"--Theodosius Dobzhansky

Does that mean abiogenesis is not part of biology or that it is part of evolution?

Does abiogenesis describe how life changes over time?

I don't recall specifying a length. Take as much time and space as necessary.

That is the space I call for. We start with Futuyma's "Evolution", and add in all of the primary peer reviewed papers over the last 20 years (at a minimum) as it applies to any specific topic.

Sound good?

I'm more than ready to move on.

Then move on.