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Author Topic:   Macro and Micro Evolution
NosyNed
Member
Posts: 8996
From: Canada
Joined: 04-04-2003


Message 241 of 301 (69797)
11-28-2003 10:17 PM
Reply to: Message 240 by Sonic
11-28-2003 10:09 PM


Re: Question
I'm not sure we do or don't?
(btw I will be out for awhile so my usual quick answers (too quick?) will slow down).
What we don't agree on is that it matters at all. There are small and large genetic changes. Some changes may cause a speciation event some don't. Some of these may be very clear and sharp, some may not be at all clear and sharp. What you choose to call a micro and what you call a macro doesn't seem to me to matter very much.
Biologists do, I understand, use the word to describe differences that are not across a species boundary and macro for those that are. Or some may use macro for difference at a level higher than genus or maybe species.
It doesn't really matter. What matters is can there be an evolutionary path that allows for a crossing of the now apparently large gaps between taxa (groupings) at some level above species.
Creationists don't agree at which level of taxonomy this boundary crossing becomes "macro" but all of them have it at not as high as crossing a family boundary.
The funny thing is, as noted earlier, the fossil record can more easily record the crossing of higher levels (takes longer, bigger changes, easier to see) than the crossing of a species boundary (which is hard to see when it happens today).

This message is a reply to:
 Message 240 by Sonic, posted 11-28-2003 10:09 PM Sonic has not replied

Asgara
Member (Idle past 2303 days)
Posts: 1783
From: Wisconsin, USA
Joined: 05-10-2003


Message 242 of 301 (69801)
11-28-2003 10:32 PM


On the Creationists as Hyperevolutionists thread, Sonic posted the following.
steps of TOE:
1. micro-e
2. (medium-e)genetic drift and hidden mutation
3. macro-e
I would be interested in what mechanisms you see as occuring in micro-e and macro-e. As has been said before, genetic drift and mutation are some of the mechanism in TOE. I don't understand the need for the differentiation.
Maybe one of the biologists here could simply list the various mechanisms that contribute to the TOE.
On the same thread Sonic also posted this:
I believe we have clarified macro-e as the development of an organ through the process of genetic drift and hidden mutation(i.e. through this process the new organ appears as if it were new and never seen and also appears as if it came out of no where). The actual definition is a little confusing so I will state it the way I did above.
I am of the opinion that if macro-e involves organs appearing as if they came out of no where, then macro-e is a moot point as far as evolution goes.
------------------
Asgara
"An unexamined life is not worth living" Socrates via Plato

Dr_Tazimus_maximus
Member (Idle past 3217 days)
Posts: 402
From: Gaithersburg, MD, USA
Joined: 03-19-2002


Message 243 of 301 (69802)
11-28-2003 10:47 PM
Reply to: Message 238 by Sonic
11-28-2003 9:37 PM


Re: Question
Well, first off the real difference between micro and macro deals with levels. When used, and that is damned seldom in most literature, macro really is discussing the larger shifts deaing with orders or classes or even higher (although there ain't much higher, number wise). SO when most people are talking evolution and micro vs macro they are really kind of screwing it up when they say speciation and up is macro. Second, I would say the beginning of evolution is whenever life started. Everything since then has been a combination of mutation and selection (and by that I include survival and extinction). Mutation includes genetic drift and both silent and non-silent mutations. Just so that I am being clear, this is in no way an endorsement of the strict Neo-Darwinian camp but rather a summation of the basic concepts that underlie the various theoretical approaches to evolution through mutation and selection. If all mutations were hidden, and by that I believe that you mean silent w.r.t. phenotypic expression, then there would be no changing of charateristics unless the aggregate effect of the mutations was not silent (which does happen). Are you sure that you are not mixing silent mutations and those which are phenotypically present but have little to no effect on fitness?
------------------
"Chance favors the prepared mind." L. Pasteur
and my family motto
Transfixus sed non mortis
Taz

This message is a reply to:
 Message 238 by Sonic, posted 11-28-2003 9:37 PM Sonic has replied

Replies to this message:
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Dr_Tazimus_maximus
Member (Idle past 3217 days)
Posts: 402
From: Gaithersburg, MD, USA
Joined: 03-19-2002


Message 244 of 301 (69803)
11-28-2003 10:50 PM
Reply to: Message 237 by NosyNed
11-28-2003 9:03 PM


Re: Sonics fundamental error
Sorry, I thought that I stayed away from Jargonese .
I will try to go into a bit more detail later if I can get away from grant writing and budget crunching .
------------------
"Chance favors the prepared mind." L. Pasteur
and my family motto
Transfixus sed non mortis
Taz

This message is a reply to:
 Message 237 by NosyNed, posted 11-28-2003 9:03 PM NosyNed has not replied

Sonic
Inactive Member


Message 245 of 301 (69804)
11-28-2003 11:04 PM
Reply to: Message 243 by Dr_Tazimus_maximus
11-28-2003 10:47 PM


Re: Question
Dr_taz writes:
Well, first off the real difference between micro and macro deals with levels. When used, and that is damned seldom in most literature, macro really is discussing the larger shifts deaing with orders or classes or even higher (although there ain't much higher, number wise). SO when most people are talking evolution and micro vs macro they are really kind of screwing it up when they say speciation and up is macro.
I didn't understand that people where trying to say that speciation and up is macro. To me Macro is simply the formation of new organs through a silent process. I believe Micro can include speciation.
Dr_taz writes:
Second, I would say the beginning of evolution is whenever life started. Everything since then has been a combination of mutation and selection (and by that I include survival and extinction). Mutation includes genetic drift and both silent and non-silent mutations.
Agreed, I am trying to adopt a new way of thinking so I dont have to use the terms Micro and Macro, but I have to find a common ground for these terms (Micro)-(Silent Genetics)-(Macro), first.
Dr_Taz writes:
Just so that I am being clear, this is in no way an endorsement of the strict Neo-Darwinian camp but rather a summation of the basic concepts that underlie the various theoretical approaches to evolution through mutation and selection.
Understood, It seems that you are trying to help me find a common ground.
Dr_taz writes:
If all mutations were hidden, and by that I believe that you mean silent w.r.t. phenotypic expression, then there would be no changing of charateristics unless the aggregate effect of the mutations was not silent (which does happen).
Sure and I think the silent portion of evolution would be a middle ground between Micro and Macro, I called it Silent Genetics.
Dr_taz writes:
Are you sure that you are not mixing silent mutations and those which are phenotypically present but have little to no effect on fitness?
No, atleast I dont think so. To me I am speaking of changes which would not be metaphoricaly present. I assume that if I was talking about a species which had a phenotypical definition, which was metaphioricaly present, but had no effect with fitness, I would not conclude, Appears as if it came out of no where.
Thank You
Sonic
[This message has been edited by Sonic, 11-28-2003]

This message is a reply to:
 Message 243 by Dr_Tazimus_maximus, posted 11-28-2003 10:47 PM Dr_Tazimus_maximus has not replied

Replies to this message:
 Message 248 by NosyNed, posted 11-29-2003 1:25 AM Sonic has not replied

sidelined
Member (Idle past 5908 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 246 of 301 (69805)
11-28-2003 11:32 PM


Excuse my ignorance,however,is there any differentiation in nature between micro and macro evolution? I mean,is there a dividing line in the real world and does this negate the actual occurence of evolution? As I understand it, microevolution is "small changes in a population's gene pool occurring over a few generations. The accumulation of microevolutionary changes can result in macroevolution which is defined as major evolutionary changes in a population's gene pool, occurring over many generations, resulting in the evolution of new species."
[This message has been edited by sidelined, 11-28-2003]

Replies to this message:
 Message 247 by NosyNed, posted 11-29-2003 1:08 AM sidelined has replied

NosyNed
Member
Posts: 8996
From: Canada
Joined: 04-04-2003


Message 247 of 301 (69807)
11-29-2003 1:08 AM
Reply to: Message 246 by sidelined
11-28-2003 11:32 PM


I think, Sidelined, you are right. There really is not big deal distinguishing micro and macro evolution. As Dr. Taz told us, the terms aren't even used all that much be the biologists.
As best as I can tell your describtion is right. But then we should wait for confirmation from someone who is closer to the road.

This message is a reply to:
 Message 246 by sidelined, posted 11-28-2003 11:32 PM sidelined has replied

Replies to this message:
 Message 249 by sidelined, posted 11-29-2003 1:41 AM NosyNed has not replied

NosyNed
Member
Posts: 8996
From: Canada
Joined: 04-04-2003


Message 248 of 301 (69810)
11-29-2003 1:25 AM
Reply to: Message 245 by Sonic
11-28-2003 11:04 PM


Re: Question
Ya know, Sonic, I think this whole 'new organs' thing is leading you off in the wrong direction. I know you are trying to use it to figure out what the distinction between micro and macro is but I'm not sure it's helpful.
As best as I can tell the whole big-deal about any distinction here is a made up problem by the creationist organizations. They did this because they were forced to accept some level of evolution. However, once they did that they had to put a stop to how far it was taken. To do this they tried to split evolution into two things: a "little" one that they had to accept and a "big" one that they didn't want to accept.
But there isn't any split. The ToE simply says changes happen, some are kept around some aren't. If you keep on changing things AND you "rachet" them by not allowing them to wander totally randomly (that is you select some and discard others) then you end up with change piling up on change. On some of the paths of change you get very little overall change (say sharks over the last 50 million years) and on other paths (because the selection conditions are different) you get a large total amount of change (say primates over the last 50 million years).
When the changes do add up to a lot we have "big" evolution. Sometimes the adding up takes a long time, but there are some changes that are genetically possible that are pretty big and happen pretty fast and the adding up doesn't take so long.
At a high level that is all there is too it. But, oh boy!, are there a lot of details at a lower level!!!
If you want new terms then you would be best to start to learn the terms that the researchers in the field use. They have been struggling with how to describe all this for decades and have lots and lots of jargon. We sure don't need to start inventing any more! Please don't!!
You have a good idea in what you call "silent genetics". However, this too has been covered by the research. A lot of genetic changes don't, immediately, have any appearance in the 'phenotype' (phenotype -- the physical appearance of the body), but just stay in the genotype (genotype -- the detials of the genes of the individual organism). If they don't have any immediate affect on the phenotype they are not subject to natural selection. If this is the case they are "silent". They may or may not gradually spread in the population or be removed.
However, a new 'silent gene pattern' may be subject to more mutations in it or be affected by other changes in the genome. "Suddenly" the mutation that occured a long time ago may have an affect on the phenotype. It may be a small affect or it may be moderately large.
Large effects are hard to manage. They are likely to result in a huge mess and kill the individual. The small ones may have a chance of being beneficial. (However, there are large changes posssible but they are probably not as common).
Aside from the silent changes, there may be innumerable small ones, some of which improve the organisms with them. This is the slow, small, "micro" steps we all accept. But there are ways for these to add up to large results over time. That is the point of transitionals.
We can see some transitions in the fossil record. We can see others in the record in our DNA. We can infer others as we learn more about the way in which gene expression is controled (e.g., the HOX gene). We don't know all the ways that transitions can happen. We will possibly never know all of them.
I think you last paragraph is trying to express some of what I have described above. We are still struggling to find words which we can all understand. We seem to be making some progress.

This message is a reply to:
 Message 245 by Sonic, posted 11-28-2003 11:04 PM Sonic has not replied

sidelined
Member (Idle past 5908 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 249 of 301 (69816)
11-29-2003 1:41 AM
Reply to: Message 247 by NosyNed
11-29-2003 1:08 AM


Nosyned
I have lately been doing some pretty intense studying in a lot of areas for these forums,since I have to try to make up for my treacherous collapse in that thread dealing with the twins and the question of relativity. I hate myself these days for not having stuck it out in school since I am so fascinated by what I used to ignore.
The gene pool here seems to be the key to the confusion.Microevolution is exactly the same,it would seem, as macroevolution, the only different factor being the length of time involved.This is,I believe, the "common ground" that sonic is looking for. He also mentioned genetic drift.
genetic drift
evolution, or change in gene pool frequencies, resulting from random chance. Genetic drift occurs most rapidly in small populations. In large populations, random deviations in allele frequencies in one direction are more likely to be cancelled out by random changes in the opposite direction.
This makes sense to me and I had to look this one up in order to best understand it.
------------------
"Physics is like sex. Sure, it may give some practical results, but that's not why we do it."

This message is a reply to:
 Message 247 by NosyNed, posted 11-29-2003 1:08 AM NosyNed has not replied

Replies to this message:
 Message 250 by Sonic, posted 11-29-2003 2:31 AM sidelined has replied

Sonic
Inactive Member


Message 250 of 301 (69826)
11-29-2003 2:31 AM
Reply to: Message 249 by sidelined
11-29-2003 1:41 AM


Divider for Micro and Macro would be Genetic drift
Yeah. I was trying to present it as silent genetics. I agree that genetic drift would be the filler between Micro-e and Macro-e, but the problem is how factual is this genetic drift, has it been observed, has it been found factual. How theoretical is it really?
If genetic drift is found true, then it fills the gap, if genetic drift is false then it leaves the gap which means that Micro-e occurs but Macro-e does not, which would mean a gap in "TOE" which cannot be filled. Essientially, Without genetic drift, their is no way Micro can lead into Macro.
Thank You
Sonic
[This message has been edited by Sonic, 11-29-2003]

This message is a reply to:
 Message 249 by sidelined, posted 11-29-2003 1:41 AM sidelined has replied

Replies to this message:
 Message 251 by sidelined, posted 11-29-2003 2:50 AM Sonic has replied
 Message 252 by Asgara, posted 11-29-2003 2:55 AM Sonic has not replied
 Message 260 by mark24, posted 11-29-2003 4:46 AM Sonic has replied

sidelined
Member (Idle past 5908 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 251 of 301 (69827)
11-29-2003 2:50 AM
Reply to: Message 250 by Sonic
11-29-2003 2:31 AM


Re: Divider for Micro and Macro would be Genetic drift
sonic
I brought this over from the talk origins archive. It is by David Suzuki et al.
"If a population is finite in size (as all populations are) and if a given pair of parents have only a small number of offspring, then even in the absence of all selective forces, the frequency of a gene will not be exactly reproduced in the next generation because of sampling error. If in a population of 1000 individuals the frequency of "a" is 0.5 in one generation, then it may by chance be 0.493 or 0.0505 in the next generation because of the chance production of a few more or less progeny of each genotype. In the second generation, there is another sampling error based on the new gene frequency, so the frequency of "a" may go from 0.0505 to 0.501 or back to 0.498. This process of random fluctuation continues generation after generation, with no force pushing the frequency back to its initial state because the population has no "genetic memory" of its state many generations ago. Each generation is an independent event. The final result of this random change in allele frequency is that the population eventually drifts to p=1 or p=0. After this point, no further change is possible; the population has become homozygous. A different population, isolated from the first, also undergoes this random genetic drift, but it may become homozygous for allele "A", whereas the first population has become homozygous for allele "a". As time goes on, isolated populations diverge from each other, each losing heterozygosity. The variation originally present within populations now appears as variation between populations." (Suzuki, D.T., Griffiths, A.J.F., Miller, J.H. and Lewontin, R.C. in An Introduction to Genetic Analysis 4th ed. W.H. Freeman 1989 p.704)
And as an experiment to test this I found this on the web.
You can simulate this situation. Let N= 10, and place 10 coins in a box. Shake the box, and count the number of heads (allele "H"). Do this several times to show that finite population size causes random changes in allele frequency. These random changes in allele frequency due to sampling error in finite populations are known as "genetic drift". Genetic drift is an evolutionary force that can alter populations through time, and shows that the Hardy-Weinberg "equilibrium" does not hold exactly for any finite population. Try using 20 coins for the simulation and repeat the experiment above several times. The results will show that there are still random deviations from 0.5, but the proportional deviation from 0.5 is smaller when N = 20 than when N = 10. This shows that the amount of evolutionary change associated with random sampling error is inversely related to population size; the larger the population, the less the allele frequency will change. Hence, genetic drift is most effective as an evolutionary force when N is small.
------------------
"Physics is like sex. Sure, it may give some practical results, but that's not why we do it."

This message is a reply to:
 Message 250 by Sonic, posted 11-29-2003 2:31 AM Sonic has replied

Replies to this message:
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Asgara
Member (Idle past 2303 days)
Posts: 1783
From: Wisconsin, USA
Joined: 05-10-2003


Message 252 of 301 (69828)
11-29-2003 2:55 AM
Reply to: Message 250 by Sonic
11-29-2003 2:31 AM


Re: Divider for Micro and Macro would be Genetic drift
Sonic, genetic drift is simply a random sampling issue between various alleles. The smaller the population, the easier that drift will affect the allele frequency in the next generation.
I may be wrong, (someone please correct me if I am), but it doesn't seem to me to be a mechanism that would need to be "proven". It is an issue of ratio.
------------------
Asgara
"An unexamined life is not worth living" Socrates via Plato

This message is a reply to:
 Message 250 by Sonic, posted 11-29-2003 2:31 AM Sonic has not replied

Sonic
Inactive Member


Message 253 of 301 (69829)
11-29-2003 3:00 AM
Reply to: Message 251 by sidelined
11-29-2003 2:50 AM


Re: Divider for Micro and Macro would be Genetic drift
Very interesting. I was actually checking into this. Another factor is technical advances. In our day we live inside, we really dont get subject to nature like life of the old have. Because we are not exposed to nature we should not Macro-e. So we have 2 factors saying observation of Macro-e is preatty much impossible in our day. Technical advances, and Genetic drift. Wow making this Macro-e factual is going to be a hard target. Observation will have to be built around history alone.
Thank You
Sonic
[This message has been edited by Sonic, 11-29-2003]

This message is a reply to:
 Message 251 by sidelined, posted 11-29-2003 2:50 AM sidelined has not replied

Replies to this message:
 Message 254 by NosyNed, posted 11-29-2003 3:24 AM Sonic has replied

NosyNed
Member
Posts: 8996
From: Canada
Joined: 04-04-2003


Message 254 of 301 (69831)
11-29-2003 3:24 AM
Reply to: Message 253 by Sonic
11-29-2003 3:00 AM


Re: Divider for Micro and Macro would be Genetic drift
I still don't think we have this macro/micro thing sorted out. If macro is a "big" change of any type then, of course, it will take a long time and be hard to observe by watching a organism like ourselves.
But we have access to organisms that are are subject to more rapid changes and have much, much shorter generational times. We can observe larger changes there.
And I wouldn't be so quick to think that we aren't subject to selective pressures. We may not be subject to some of those that we were in the wild but we are subject to new ones.
For example, we now live crowded up with a very much larger number of our own species. This allows the transmission of diseases that could not take hold when we were spread more thinly. We will evolve subject to those pressures to the degree that medicine can not keep up with them.
I wouldn't expect to ever see all selective pressures removed. Sexual selection will remain for one thing. And it we mustn't ignore why they call them "Darwin Awards"

This message is a reply to:
 Message 253 by Sonic, posted 11-29-2003 3:00 AM Sonic has replied

Replies to this message:
 Message 255 by Sonic, posted 11-29-2003 3:35 AM NosyNed has not replied

Sonic
Inactive Member


Message 255 of 301 (69833)
11-29-2003 3:35 AM
Reply to: Message 254 by NosyNed
11-29-2003 3:24 AM


Post removed. Sorry guys I was confused
Thank You
Sonic
[This message has been edited by Sonic, 11-29-2003]

This message is a reply to:
 Message 254 by NosyNed, posted 11-29-2003 3:24 AM NosyNed has not replied

Replies to this message:
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