Author Topic: Micro vs macro and genetic mutations  (Read 1911 times)

0 Members and 1 Guest are viewing this topic.

Offline Rustybeatz

  • Student
  • **
  • Posts: 93
  • Darwins +3/-0
  • Gender: Male
  • WWGHA Member
Micro vs macro and genetic mutations
« on: May 28, 2012, 05:10:52 PM »
My wife bought me a book called "Who made God?" by Edgar Andrews in an attempt to prove god through science.  Andrews is a Christian scientist and the book describes him as "an international expert on the science of macromolecules".  He also debated Dawkins sometime during the 80's.  There is a section of the book where he talks about evolution.  He accepts micro, but not macroevolution.  I've become somewhat familiar with these terms, but I don't understand the argument behind it.  I mean, I understand what the words micro and macro mean and that macroevolution is just long term microevolution.  I've read up on it a little and searched the threads but I guess I still don't understand and I feel I may benefit from a two way conversation where I can ask specific questions.  I've heard the argument that macro can't happen because the mutations stop at a certain point and doesn't allow for large scale change or something.  In the book, Andrews says that mutations can only lose genetic information and not create it.  I'm confused about that also.  I understand how natural selection works (and it is awesome) and also selective pressures and a little bit about genetic drift, but I'll admit I don't know much about mutations.  I know they're mistakes during DNA transcription, but how is genetic information continually lost?  To me, he makes it sound like everything should be deteriorating instead of...I guess, diversifying?  Hell, I don't know, I'll just ask questions as people start responding lol.

Offline Mooby

  • Reader
  • ******
  • Posts: 1196
  • Darwins +71/-24
  • So it goes.
    • Is God Imaginary?
Re: Micro vs macro and genetic mutations
« Reply #1 on: May 28, 2012, 08:24:43 PM »
Microevolution and macroevolution mean slightly different things to the scientific community than to Creationists.

If we start with organisms and work our way up, we branch into populations within the same species and then communities of populations from multiple species.

Microevolution is change in the gene pool of a population over time.  So evolution in a population of birds from one species in one location would be microevolution.

Macroevolution is change at the species level or higher.  This can be the result of several microevolution changes over a long time scale, or it could be something more dramatic such as a bottlenecking or mass extinction.  For instance, if a disaster hits an ecosystem and kills off large amounts of organisms from multiple species, this could result in a change in multiple population gene pools in a very short period of time.  Natural selection is just one mechanism by which evolution takes place; any event that changes the gene pool causes evolution.

The Wiki page on macroevolution talks about whole genome duplication in plants.  I don't know much about that subject, but it sounds like an area you could look into for details on larger scale mutations.

The things a lot of Creationists forget, though, is that species is a man-made classification.  We usually made the distinction based on mating, and there are quite a few species that fall into the "gray" area when their various populations mate: they might have the potential to cross-mate but they don't, or they may be willing but make nonviable offspring, or they may be willing in lower frequencies between populations than within, etc.  Some Creationists get around this by talking about "kinds," but this isn't something recognized by biologists and I've never really seen them attempt to offer a physiological delineation between these "kinds."

So the question to me is, "Where's the barrier?"  And I've yet to hear a precise answer on that.  Sure, you'll get separate evolutionary paths - other primates and modern humans, or if they're feeling facetious, dogs and cats.  But you probably won't hear them say, "There's X factor that prevents one population from ever creating a new species/genus/family/whatevs."  And if you do, be sure to let us know so we can discuss it and see its merits.


As for mutations, they refer to changes in DNA during DNA replication.  DNA is coded with 4 bases (A, T, C, G) that work to make proteins.  For simplicity I'll only talk about the ones actively used in coding to proteins.

When a protein is ready to be coded, part of the DNA unwinds and translates the unwound section onto a piece of RNA.  This RNA travels to a processing center called a ribosome, which reads each code 3 letters at a time.  Simple math gives us 64 possible 3 letter codes (AAA, AAC, AAG...).  Each of these codes is mapped to one of the 20 amino acids (yes, this means there is redundancy in the coding.)  The ribosome strings those amino acids together until it receives the STOP code.  The completed structure is a protein.

A mutation is a change to a DNA code.  A code (AAG) can have a base substituted substituted (ACG), reversed (GAA), moved to another place, deleted (A*GC), inserted (AAA), etc.  Some of these mutations are worse than others: a substitution means one amino acid is off, while a deletion or insertion changes everything after it (called a frameshift).  Accidentally adding or removing a STOP code will drastically change the length of the protein, and a frameshift will make something completely different.

For proteins to function, they have to fold and bond.  As a result, screwing up their amino acids almost always makes the protein nonfunctional.  Only rarely does this create a functional protein, and when it does it's usually a neutral change.  This is why Creationists argue that mutation can only be deleterious.  For us to get anything useful out of mutation, they argue, we'd have to have several lucky beneficial mutations in a row without killing the organism.

At face value that argument seems somewhat reasonable, but it's simply not true.  Beneficial mutations may be rare but they do happen, and if they're of significant benefit then they'll spread through the population.  And neutral mutations might not seem very special, but multiple neutral changes can have a net benefit.  This is especially true because organisms are pragmatists, and will use a tool however they need to for survival.  Sure, your limb might not have specifically evolved to climb a tree, but if it's a matter of life and death, you're going up.  And if you have a "neutral" mutation granting you stronger nails... well, it might not be so neutral for you after all.  And in a few generations, those nails might be claws and your descendents might be tree dwellers.

The other thing to remember is that mutation means a different thing to complex organisms than it does to bacteria.  Your body has several safeguards to keep mutations away, while a bacteria does not.  So for us, our evolutionary changes tend to occur along traits already in our population rather than new mutations.  Kill off all the tall people, and the average height goes down.  Kill off all the short people, and the average height goes up.  Kill off everyone in the middle, and you're left with two populations: giant and dwarf.  Keep the separate long enough, and they'll evolve into two separate species.

"I'm doing science and I'm still alive."--J.C.

Online wright

  • Reader
  • ******
  • Posts: 1871
  • Darwins +79/-1
  • Gender: Male
  • "Sleep like a log, snore like a chainsaw."
Re: Micro vs macro and genetic mutations
« Reply #2 on: May 28, 2012, 08:31:13 PM »
In the book, Andrews says that mutations can only lose genetic information and not create it.  I'm confused about that also.  I understand how natural selection works (and it is awesome) and also selective pressures and a little bit about genetic drift, but I'll admit I don't know much about mutations.  I know they're mistakes during DNA transcription, but how is genetic information continually lost?  To me, he makes it sound like everything should be deteriorating instead of...I guess, diversifying?  Hell, I don't know, I'll just ask questions as people start responding lol.

I'm no biologist, just an interested layman, but I'll take a stab at it.

The claim that mutations can only subtract genetic information and never add to it is a recurring one. Like virtually every creationist claim, it's also wrong. One mechanism for adding new information is gene duplication, which has been shown to happen in many species; here's a link to a decent summary of the process:http://www.talkorigins.org/indexcc/CB/CB102.html

The vast majority of mutations are neutral, giving an organism neither a significant advantage or disadvantage. But natural selection, as you pointed out, will ruthlessly seize on either and change a population accordingly.

The things a lot of Creationists forget, though, is that species is a man-made classification.  We usually made the distinction based on mating, and there are quite a few species that fall into the "gray" area when their various populations mate: they might have the potential to cross-mate but they don't, or they may be willing but make nonviable offspring, or they may be willing in lower frequencies between populations than within, etc.  Some Creationists get around this by talking about "kinds," but this isn't something recognized by biologists and I've never really seen them attempt to offer a physiological delineation between these "kinds."

So the question to me is, "Where's the barrier?"  And I've yet to hear a precise answer on that.  Sure, you'll get separate evolutionary paths - other primates and modern humans, or if they're feeling facetious, dogs and cats.  But you probably won't hear them say, "There's X factor that prevents one population from ever creating a new species/genus/family/whatevs."  And if you do, be sure to let us know so we can discuss it and see its merits..

Exactly. I've asked creationists on this forum more than once how "micro" cannot add up to "macro", what absolute barrier separates them. Haven't gotten an answer yet.
Live a good life... If there are no gods, then you will be gone, but will have lived a noble life that will live on in the memories of your loved ones. I am not afraid.
--Marcus Aurelius

Offline jetson

  • Administrator
  • *******
  • Posts: 7277
  • Darwins +170/-6
  • Gender: Male
  • Meet George Jetson!
    • Jet Blog
Re: Micro vs macro and genetic mutations
« Reply #3 on: May 28, 2012, 09:00:45 PM »

Exactly. I've asked creationists on this forum more than once how "micro" cannot add up to "macro", what absolute barrier separates them. Haven't gotten an answer yet.

You will never get an answer.  The best I've heard is that God intervenes.  Unbelievable.

Offline rickymooston

Re: Micro vs macro and genetic mutations
« Reply #4 on: May 28, 2012, 09:19:34 PM »


Exactly. I've asked creationists on this forum more than once how "micro" cannot add up to "macro", what absolute barrier separates them. Haven't gotten an answer yet.

Lol., i can answer that.

Do you know anything about mathematics? For the record, i actually do believe the evidence has established that macro is micro but that is not a trivial result; it was a major revelation. Darwin gathered twenty yesrs of dsta on it. He also built on the disciveries of others. Further science showed he was right to some extent.

Imagine random vectors in three space where all the mutations only happen along the x and y axis. No matter how many mutations you get, the result of adding tgese vectors will always be in the plane

Imagine some mutations like increading or reducing the number of chromosomes in an organism. Again, its not obvious this sortvof thing occurred.Resesrch was required to prove it.

The complexity of a human is immense. It is hardly obvious that a slightly directed random walk with natural selection could go from amoeba to us.

So again, the question "how could micro not macro" lacks imagination. The reality is, a hell of a lot of hard work was done and is being done that seems to suvgest macro comes from micro. Future scientific findings may show this to be a simplification.
"i had learn to focus i what i could do rather what i couldn't do", Rick Hansen when asked about getting a disabling spinal cord injury at 15. He continues to raise money for spinal cord research and inspire peoople to "make a difference". He doesnt preach any religion.

Online wright

  • Reader
  • ******
  • Posts: 1871
  • Darwins +79/-1
  • Gender: Male
  • "Sleep like a log, snore like a chainsaw."
Re: Micro vs macro and genetic mutations
« Reply #5 on: May 28, 2012, 09:45:14 PM »


Exactly. I've asked creationists on this forum more than once how "micro" cannot add up to "macro", what absolute barrier separates them. Haven't gotten an answer yet.

Lol., i can answer that.

Do you know anything about mathematics? For the record, i actually do believe the evidence has established that macro is micro but that is not a trivial result; it was a major revelation.

Who's claiming it was trivial?

Darwin gathered twenty yesrs of dsta on it. He also built on the disciveries of others. Further science showed he was right to some extent.

No argument. Science builds on its predecessors; even the failures serve as examples.

Imagine random vectors in three space where all the mutations only happen along the x and y axis. No matter how many mutations you get, the result of adding tgese vectors will always be in the plane

And this has what to do with your point?

The complexity of a human is immense. It is hardly obvious that a slightly directed random walk with natural selection could go from amoeba to us.

Not obvious, agreed. But the progression of life on this planet from simpler to more complex organisms is borne out in the fossil record, comparative zoology and genetics. No other explanation currently fits the evidence better.

So again, the question "how could micro not macro" lacks imagination. The reality is, a hell of a lot of hard work was done and is being done that seems to suvgest macro comes from micro. Future scientific findings may show this to be a simplification.

Lacks imagination how? And I don't really see an answer in your post. At least, one that disagrees with mine.
Live a good life... If there are no gods, then you will be gone, but will have lived a noble life that will live on in the memories of your loved ones. I am not afraid.
--Marcus Aurelius

Offline rickymooston

Re: Micro vs macro and genetic mutations
« Reply #6 on: May 28, 2012, 10:08:50 PM »
You asked, "how could macro not equal micro", the statement of the question implies another hypothesis could not exist. I supplied analagy from mathematics and also alluded to the so-called information argument.
Note, I am discussing logic here as I believe macro is in fact reached by micro.

Darwin proved micro and macro are the same. People knew about "micro" for thousands of yesrs; they were involved in breeding plants and animals, selecting the traits they liked and rejecting others. Indeed, this was an area of evidence he considered. He also observed other instances of micro directly and he examined the fossil record.

If we only knew about micro and didnt have the fossil record dtsring us in the face, one might stiil guess micro caused macro but it would not prove it.

Creationists make some valid points out of context,  lol. For example, when we study the fossil record, we look at similar forms in simular locatiins placed in order of layers  but we cannot lol verify one fossil is descended from another. (i confess, i dont know if DNA can be obtained from any fossils or not. I assume not.). I think
"i had learn to focus i what i could do rather what i couldn't do", Rick Hansen when asked about getting a disabling spinal cord injury at 15. He continues to raise money for spinal cord research and inspire peoople to "make a difference". He doesnt preach any religion.

Online wright

  • Reader
  • ******
  • Posts: 1871
  • Darwins +79/-1
  • Gender: Male
  • "Sleep like a log, snore like a chainsaw."
Re: Micro vs macro and genetic mutations
« Reply #7 on: May 28, 2012, 10:52:32 PM »
Creationists make some valid points out of context,  lol. For example, when we study the fossil record, we look at similar forms in simular locatiins placed in order of layers  but we cannot lol verify one fossil is descended from another. (i confess, i dont know if DNA can be obtained from any fossils or not. I assume not.). I think

DNA can be extracted from very old biological material, though there is of course considerable degradation. Not fossils as such, but pollen trapped in ice cores, insects sealed in amber, mummified humans... Here's a wiki article on the topic:http://en.wikipedia.org/wiki/Ancient_DNA

And while maybe we can't definitively verify descent from one fossil organism to its successors, in observed ancestral lineages like the various dinosaur species, whales, horses and humans, that's still the best explanation for the observed similarities within those lineages.
Live a good life... If there are no gods, then you will be gone, but will have lived a noble life that will live on in the memories of your loved ones. I am not afraid.
--Marcus Aurelius

Offline rickymooston

Re: Micro vs macro and genetic mutations
« Reply #8 on: May 28, 2012, 10:57:45 PM »
 ;D
"i had learn to focus i what i could do rather what i couldn't do", Rick Hansen when asked about getting a disabling spinal cord injury at 15. He continues to raise money for spinal cord research and inspire peoople to "make a difference". He doesnt preach any religion.

Offline Rustybeatz

  • Student
  • **
  • Posts: 93
  • Darwins +3/-0
  • Gender: Male
  • WWGHA Member
Re: Micro vs macro and genetic mutations
« Reply #9 on: May 30, 2012, 11:11:27 AM »
Microevolution and macroevolution mean slightly different things to the scientific community than to Creationists.

I hate it that they always take words and change the meanings!!  "It's only a theory". 

If we start with organisms and work our way up, we branch into populations within the same species and then communities of populations from multiple species.

Microevolution is change in the gene pool of a population over time.  So evolution in a population of birds from one species in one location would be microevolution.

Macroevolution is change at the species level or higher.

Ok, this makes sense to me. 

So the question to me is, "Where's the barrier?"  And I've yet to hear a precise answer on that.  Sure, you'll get separate evolutionary paths - other primates and modern humans, or if they're feeling facetious, dogs and cats.  But you probably won't hear them say, "There's X factor that prevents one population from ever creating a new species/genus/family/whatevs."  And if you do, be sure to let us know so we can discuss it and see its merits.

Yes!!  This is the exact question I have!  Where is the barrier, where does it stop exactly?!?  Anything that I've read on this has never clarified.  I should have known when he started mentioning Michael Behe though.
However he did say something that I was wondering about.  He states "mutations have never been found to create new protein-to-protein binding sites as would be necessary for the formation of novel molecular machinery within the cell".  In other words, he's saying that no new biological structures are ever formed.  I get lost on that one. 


The other thing to remember is that mutation means a different thing to complex organisms than it does to bacteria.  Your body has several safeguards to keep mutations away, while a bacteria does not.  So for us, our evolutionary changes tend to occur along traits already in our population rather than new mutations.  Kill off all the tall people, and the average height goes down.  Kill off all the short people, and the average height goes up.  Kill off everyone in the middle, and you're left with two populations: giant and dwarf.  Keep the separate long enough, and they'll evolve into two separate species.
This also makes sense, thank you. 
Another thing he did when talking about the mechanisms of evolution is he broke down each one - natural selection, selective pressures, mutations - and spoke about one at a time.  And even with in this he would only speak about one kind of incident.  For example, when talking about natural selection he used rabbits vs foxes and described a way where rabbits survived because of a gene that made them faster.  He then says that in order for the foxes to survive, they would too aquire a running gene because the slower foxes would die out so the rabbits wouldn't have an advantage anymore.  He described this as an arms race.  So in his mind, it doesn't really work.  He then did the same thing with selective pressures, etc.  However, I'm thinking that it's all of these things happening simultaneously, with multiple pressures, prominent genes, etc going on rather than just one scenario at a time.  It sounds to me like he's oversimplifying or not including all possibilities.


The claim that mutations can only subtract genetic information and never add to it is a recurring one. Like virtually every creationist claim, it's also wrong. One mechanism for adding new information is gene duplication, which has been shown to happen in many species; here's a link to a decent summary of the process:http://www.talkorigins.org/indexcc/CB/CB102.html

The vast majority of mutations are neutral, giving an organism neither a significant advantage or disadvantage. But natural selection, as you pointed out, will ruthlessly seize on either and change a population accordingly.

I dig talkorigins but I have to admit I haven't been there in a while.  Thank you for the link, I'll check it out and see what it says.

Exactly. I've asked creationists on this forum more than once how "micro" cannot add up to "macro", what absolute barrier separates them. Haven't gotten an answer yet.

You will never get an answer.  The best I've heard is that God intervenes.  Unbelievable.
They're going to have to dig deeper than that!  lol 
Ay Ay Ay, I hope I can find something better than that.

Offline Mooby

  • Reader
  • ******
  • Posts: 1196
  • Darwins +71/-24
  • So it goes.
    • Is God Imaginary?
Re: Micro vs macro and genetic mutations
« Reply #10 on: May 30, 2012, 03:29:12 PM »
I hate it that they always take words and change the meanings!!  "It's only a theory".
It's unfortunate when words have two very different meanings in a technical and casual context.  Some Creationist sites (like Answers In Genesis) go out of their way to outline this difference, so it's unclear to me to what extent they do this intentionally and to what extent it's simple misunderstanding of the context in which the word is used.  Remember, most of these people are hearing about evolution for the first time at their churches, in which a simple misunderstanding 20 years ago may still be propagated to each new generation.

But yes, it is frustrating.

Quote
Yes!!  This is the exact question I have!  Where is the barrier, where does it stop exactly?!?  Anything that I've read on this has never clarified.  I should have known when he started mentioning Michael Behe though.
Unfortunately for him, nature doesn't play by our rules.  Draw any line in development, and you'll almost certainly find at least one thing that straddles it.  Divide organisms into species, and you'll find populations that meet some parts of the definition but not all.  Divide into kingdoms, and you'll find something that doesn't quite fit into any kingdom.  If you Google around you'll find multiple versions of the classification system out there, because nature cares so little about these things that we can't even agree on what the best categories are, let alone trying to fit things in.

So if all the lines are blurry when you look close enough, how can we point to one and say, "Nature can't cross it?"  I think you'll be hard pressed to find an answer that doesn't invoke the Biblical "kinds," ask whether dogs can evolve into cats, or invoke some variation of the watchmaker analogy.  I've yet to hear a direct, concrete answer to the question, and that's probably because such a barrier is not known to exist.

Quote
However he did say something that I was wondering about.  He states "mutations have never been found to create new protein-to-protein binding sites as would be necessary for the formation of novel molecular machinery within the cell".  In other words, he's saying that no new biological structures are ever formed.  I get lost on that one.

Yeah, I'm not sure what he's trying to say, either.  Is he alluding to Michael Behe's criticism of the bacteria flagella?  (I know Behe likes to refer to the flagellum as a piece of "machinery.")  Is there anything in the context that makes this more clear?

Quote
For example, when talking about natural selection he used rabbits vs foxes and described a way where rabbits survived because of a gene that made them faster.  He then says that in order for the foxes to survive, they would too aquire a running gene because the slower foxes would die out so the rabbits wouldn't have an advantage anymore.  He described this as an arms race.  So in his mind, it doesn't really work.
He is describing coevolution, where evolutionary changes in one organism results in changes in another organism.  This can happen in many different interactions: cooperation, competition, predation, etc.  With predation, it is indeed an arms race.  However, I'm not seeing why it wouldn't work.

He is likely oversimplifying.  Taking it a step further, what does a "gene to run faster" mean in real world terms?  Is it like a part to make your car fun faster?

Just looking at the wall of text on that page should tip you off that it's definitely not that simple.  What does running faster mean in terms of leg muscles, bone density, overall weight, size, shape, etc?  Intuition tells us that stronger leg muscles will make us run faster, but that losing weight will also make us run faster.  So let's increase our rabbit's leg muscles, trim some weight from the belly, lighten the bones a bit, and crank up the metabolism for good measure.

Ok, so we've now increased our energy consumption while decreasing our energy stores.  So now we need to eat twice as often to stay healthy.  Of course, that means we're in the open twice as long, so we're more vulnerable to attacks, and have less time for mating.

Are we optimizing for sprinting or long distance, or are we going to do a moderately good job at both?  Do we want to grow larger so we can store a bit more food, or get smaller so we can find more hiding places?  Do we want to focus our muscles on blind speed so we can outrun our predators, or agility so we can outmaneuver them?  Do we want to make you smarter so you can be less predictable, or reduce some brain mass to save some energy?  And will adding more leg muscles make you look more tasty?

And then once we find the best match, the fox evolves to match it.  Maybe they get stronger legs to go faster, or maybe they increase their mobility, or they get smaller so they can follow more easily, or they get smarter so they can predict behavior, or they get quieter so they can ambush better (which means more delicate movements, smaller size, change in body proportions, etc.), or they optimize for sprinting, or they optimize for endurance...

So while it's definitely an arms race, I think he's picturing this as each side becoming like The Flash.  But every improvement comes with a price, and the goal isn't to maximize one thing but rather to stay one step ahead of the other.  So what this really amounts to is a complex evolutionary version of rock-paper-scissors.

And yeah, that's not even factoring in all the other stuff you mentioned.
"I'm doing science and I'm still alive."--J.C.