Macro Vs. Micro Evolution

[ScaryPirateMan]

I am a recovering Christian (you know, like a recovering alcoholic. Get it?) and I still have a hard time believing in evolution. I've always believed in micro evolution, but only in the sense that we were created as humans, and adapted into the many colors and features that we boast today. Would it be safe to say, though, that micro evolution started with homo habilis or even earlier and snowballed into macro evolution? I don't know, the way schools always talked about it was that there was one type of less evolved man and then poof, there was the next best thing and they killed them off and it kept moving in that cycle until we have us today.

 

 

[insane_alien]

well, 'macro' evolution is just the logical consequence of 'micro' evolution (i put them in quotes because the distinction does not exist, they are all the same)

 

many small changes can add up to massive changes over time.

 

this said, it seems you think that there have always been humans of some kind, this is not the case. animals resembling humans have only been around for a few million years. if you could trace your family tree back a few tens of millions of years you'd find some shrew like creatures, go even further back and you'll find some fish. go even further back than that an you'll find some single celled organisms.

 

all changes in evolution are gradual generation to generation changes.

[ScaryPirateMan]

well, 'macro' evolution is just the logical consequence of 'micro' evolution (i put them in quotes because the distinction does not exist, they are all the same)

 

many small changes can add up to massive changes over time.

 

this said, it seems you think that there have always been humans of some kind, this is not the case. animals resembling humans have only been around for a few million years. if you could trace your family tree back a few tens of millions of years you'd find some shrew like creatures, go even further back and you'll find some fish. go even further back than that an you'll find some single celled organisms.

 

all changes in evolution are gradual generation to generation changes.

 

I understand what your saying, but you have to see where I'm coming from as well. According to the beliefs of the superstition that I came from, there is/was a God that made everything. I still don't know if I fully discount intelligent design from the equation as there still seem to be gaps in both sides of the story. I'm just wondering, really, how many small changes, or how significant, makes a macro-level change?

[Mr Skeptic]

Well, I suppose micro and macro evolution are useful terms, but they shouldn't be confused for two distinct things. The distinction is arbitrary, and no one really defines what specifically is the difference, although some Christians define macroevolution in such a way as to be incompatible with the theory of evolution. Anyways, I liken it to microerosion and macroerosion. Call them what you like, one is just more of the other.

 

Anyhow, you don't really even have to understand how evolution can work to see that it has happened. I've yet to see a christian who can explain why the retroviral DNA embedded in our genomes matches the retroviral DNA in related species, nor why we have broken retroviral DNA in our genome in the first place. For evolutionists this is no surprise and in fact expected because retroviruses are a type of virus that inserts itself in the DNA of its host, just another type of mutation that can and does and has happened.

[ScaryPirateMan]

Well, I suppose micro and macro evolution are useful terms, but they shouldn't be confused for two distinct things. The distinction is arbitrary, and no one really defines what specifically is the difference, although some Christians define macroevolution in such a way as to be incompatible with the theory of evolution. Anyways, I liken it to microerosion and macroerosion. Call them what you like, one is just more of the other.

 

 

so then, would you say using the term macro evolution is just a way for skeptics to try and disprove such theories? By saying that you can't just change from a monkey to man?

[Mr Skeptic]

so then, would you say using the term macro evolution is just a way for skeptics to try and disprove such theories? By saying that you can't just change from a monkey to man?

 

Not disprove, but confuse. Macroevolution is defined such that it cannot be observed, and then they complain that it has never been observed. Then they say the failure to observe it means that the theory of evolution is wrong, even though it is the theory of evolution that says it can't be observed (either in a given timeframe or because they defined it inconsistent with evolution).

[ScaryPirateMan]

Okay then. I see what you mean by that. So then the theory of evolution isn't that you'll see neandrathals all of a sudden giving birth to cro-magnons, but that slight changes over a long timeline will eventually produce a new species.

[insane_alien]

yes, thats it exactly.

 

you won't suddenly see a fish give birth to a frog or something crazy like that.

 

a good place to look is to the history of dog breeding. dogs only exist because of us human imposing extra selective pressures on wolves.

 

or horticulture is another example.

 

the only difference between those and 'natural' evolution is the source of the selection pressure. for instance, it is usefl for a prey animal to be faster, so the faster individuals will survive better and breed more.leading to less slower ones.

 

this might have physical manifestations as well such as longer legs to allow for faster running.

 

again it's tiny minute changes that just build up over the generations.

[Mr Skeptic]

Yes, and over time the changes accumulate to big differences, and when the differences are enough we call them separate kinds, where "kind" could be at the level of any of

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Primates

Family: Hominidae

Subfamily: Homininae

Tribe: Hominini

Genus: Homo

Species: H. sapiens

and some in between, depending on how different you want your kinds to be and how many categories you have. The farther up this list you go, the longer since the various species in the category shared a common ancestor. (there are however a few categories that aren't based on common descent in various ways. Such categories are called paraphyletic (contains an ancestor but not all descendants of it) or polyphyletic (contains distantly related groups without including their common ancestor and all its descendants). For example, reptiles are paraphyletic (include the common ancestor of birds but exclude birds), whereas warm-blooded is polyphyletic (includes birds and mammals but not species in between).

http://en.wikipedia.org/wiki/Phylogenetics

[Darwinsbulldog]

I am a recovering Christian (you know, like a recovering alcoholic. Get it?) and I still have a hard time believing in evolution. I've always believed in micro evolution, but only in the sense that we were created as humans, and adapted into the many colors and features that we boast today. Would it be safe to say, though, that micro evolution started with homo habilis or even earlier and snowballed into macro evolution? I don't know, the way schools always talked about it was that there was one type of less evolved man and then poof, there was the next best thing and they killed them off and it kept moving in that cycle until we have us today.

 

Science is not about belief, or lack of belief, it is about testing various ideas to destruction and seeing what the evidence leaves you with. Credulity or incredulity has nothing to do with it.

 

Nevertheless, there has been something of a "credibility gap" with coding mutations [ie. changes in proteins] being able to supply enough variation to supply the diversity observed. But since the 1980's advances in non-coding DNA elements, such as Hox genes and clusters have explained why it is possible for a single mutation in Hox expression to have huge morphological and phenotype effects, and thus be visible to selection. In other words, the concept of the "hopeful monster" as Gould and others have called it, has regained respectability. Knockout experiments and "rescue" experiments have not only elucidated many of the mechanisms of development, but shown how these genes are both highly conserved, and yet able to produce huge changes to morphology. Hox genes have been around since at least the times of the Cambrian "explosion", over half a billion years ago, and the first "proto-Hox" genes seem to predate the bilateria. [Animals that show bilateral symmmetry, like us: two eyes, two legs..a mirror image on each side].

 

Plants have their own Genetic Regulatory Networks [GRN's] called MADS genes.

 

The interaction of sex determining genes and the Hox family of genes explains how sexual dimorphism works too. Some animal sex determination pathways can be activated by temperature [eg Crocodiles], and of course hormones and other [internal and external] environmental inputs.

A good book for the layperson is by Sean B. Carroll [note the "B" as there is a creationist called Sean Carroll also!]

 

Carroll, S. B. (2005). Endless Forms Most Beautiful:The New Science Of Evo-Devo and the Making Of The Animal Kingdom. London, Phoenix.

 

If you want to go into more technical detail:-

 

Carroll, S. B. (2005). "FROM DNA TO DIVERSITY: Molecular Genetics and The Evolution Of Animal Design". Oxford, Blackwell.

 

Carrol is not the only good source on this stuff, [there are plenty of other good sources] but I am more familiar with the material in these books because I own them. [And they are getting pretty dog-eared!]

 

Another interesting source on evo-devo and macroevolution for the layperson is:-

 

Shubin, N. (2009). "YOUR INNER FISH: The Amazing Discovery Of Our 375-million-year-old Ancestor". London, Penguin.

 

A very technical book on evo-devo is:-

 

 

Minelli, A. a. F., Giuseppe, Ed. (2008). Evolving Pathways Key Themes in Evolutionary Developmental Biology. Cambridge, Cambridge University Press.

 

A very dated, but prescient book by S.J. Gould:-

 

GOULD, S. J. (1977). "ONTOGENY and PHYLOGENY". Cambridge, Mass & London, UK., Belknap, Harvard University Press. [Heavy-going, but worth it. ]

 

Of course, now that I have given you some key-words, you can find some sources on google scholar.

 

Enjoy, and if you have any further questions, please ask.

Edited September 29, 2010 by Darwinsbulldog

[the asinine cretin]

I'm hoping a biologist will happen upon this and be kind enough to reply. I've been trying to come up with a short summary of what I understand the distinction to be between micro and macro evolution. Is the following correct? If not, what would be correct? Thanks.

 

Microevolution refers to evolution at the species level. Evolution as it occurs above the species level involves microevolution and speciation, which is sometimes referred to as macroevolution.

 

 

Basically, the distinction comes down to evolution (so-called "microevolution") within populations that are exchanging genetic information vs. microevolution between gene pools that are separate and necessarily diverging. Thus, microevolution will not produce new species on its own (e.g., a dog will never bring forth a non-dog), but if speciation occurs microevolution may produce distinct lines of descent that can become highly divergent over time (e.g., the split at the common ancestor between hippos and cetaceans has lead to very distinct species).

 

I would also welcome and appreciate book recommendations.

 

Regards.

 

P.S. If any creationists happen upon this I would be curious to hear what you understand "macroevolution" to mean. I encounter these terms in the context of creationist argumentation almost exclusively anyway.

Edited May 22, 2012 by the asinine cretin

[doG]

Ring species are a good example of how microevolution accumulates into macroevolution given time.

[the asinine cretin]

Ring species are a good example of how microevolution accumulates into macroevolution given time.

I'm familiar with ring species but I don't know what you mean. How are you defining macroevolution and why are ring species a good example of this?

[doG]

I'm familiar with ring species but I don't know what you mean. How are you defining macroevolution and why are ring species a good example of this?

Ring species are an example of speciation that results from accumulated microevolution, otherwise called adaptation or mutation driven by natural selection. The resultant speciation could be categorized as macroevolution, particularly at the end populations where the ability to interbreed has been interrupted by the accumulated change.

[the asinine cretin]

Ring species are an example of speciation that results from accumulated microevolution, otherwise called adaptation or mutation driven by natural selection. The resultant speciation could be categorized as macroevolution, particularly at the end populations where the ability to interbreed has been interrupted by the accumulated change.

 

Again, I'm familiar with what ring species are. I was hoping for a summary description of macroevolution and an elucidation of why ring species are a particularly good example of this. The problem I have with ring species as an example of macroevolution is the possibility of gene flow and ambiguity. I do think that ring species are good for illustrating why categorical thinking about species is wrong. Where I'm coming from here is trying to communicate with a creationist. My concern is that the ring species example might complicate things.

[doG]

Where I'm coming from here is trying to communicate with a creationist. My concern is that the ring species example might complicate things.

IMO the creationist is the complication you'll have to deal with regardless of the examples you dig up

[the asinine cretin]

IMO the creationist is the complication you'll have to deal with regardless of the examples you dig up

 

Truth.

[sammy7]

hay asinine cretin

 

ok so i will just start by saying mutations (whatever types)=noise ie i smash my keyboard and bunch of random stuff comes up, as opposed to a well written out sentence like this which="information" (it is conveying a message) this is very preliminary i will read more. so mutations just seem to add "noise" if you will NOT new information (like for a functional protein that the wild type doesnt have, if this had actually been observed this would give minor creedence to you know what lol.

 

ok so basically whenever i read evolutionary biology sites the word "evolution" is used as a general term to encompass one or ALL of the following (it depends on the site,) variation within a kind (like dog has white haired kids black haired kids ), speciation-ok i dont fully get this one yet but so i wont comment (note that there is never an increase in information here i will read more), umm and yeh pretty much anything meaning a change in dna/or genes or whatever (so if i have a kid=evolution lol) and also though...(this is where the tricky bit comes in imo)-to mean origin of life from bacteria or something (note this would take an incerase in "information" NEW properly sequenced dna for NEW proteins which serve a NEW purpose-again this has never been observed (which is why im looking for literature on it)......so knowing the huge range of the definition of the word makes it easier to read the stuff and take note of when they are just referring to standard stuff which we see all the time (variation) and take note of when the meaning switches to that of the never observed one (like when big changes are implied, like bacteria to a fish or something...) so yeah....so i guess all the things that have been observed one might call micro-evolution (variation speciation etc) and its hard to actually name something that has never been observed that said macro-evolution would be when they are referring to/implying origins of life/fish to fish with legs or something lol) but again we would have to actually observe this to rightly call it macro-evolution, as the term is for a process that doesnt exist (or hasnt been observed)...

 

also the ecoli experiment (lenksis its on the actual website only 6 pages) starts with "Parallel and convergent changes across lineages are hallmarks of adaptive evolution" so i think this is horizontal gene transfer (unicellular things can swap bits of dna it seems, dont fully understand it yet, just pass em right through there cell membrane ) again notice the word evolution is used in this context and it would just be referring to micro-evolution if one wished to call it that, but as this is in actual peer reviewed literature itself (not just an overview) it may be deceptive.....also horizonal gene transfer seems to be a way somethings can pass around or "swap" dna that grants them "antibiotic resistance" (in commas coz i dont know the exact mechanism of action behind it yet)...so yeh hope that helps i will read more...

[CharonY]

I'm hoping a biologist will happen upon this and be kind enough to reply. I've been trying to come up with a short summary of what I understand the distinction to be between micro and macro evolution. Is the following correct? If not, what would be correct? Thanks.

 

Microevolution refers to evolution at the species level. Evolution as it occurs above the species level involves microevolution and speciation, which is sometimes referred to as macroevolution.

 

 

That is historically correct, however, note that it is not a mechanism per se, but used to describe events at a given level. Events that span several gene pools as e.g. the split of species can be referred to as macroevolution. Or the investigation of divergence in different species.

However it is not quite correct to say that macroevolution leads to speciation. The molecular mechanisms are essentially the same for macro and microevolution, just the viewpoint (and timescale) of investigation is different.

 

 

[the asinine cretin]

sammy, I'm on my way out the door but I've seen your post and will reply later.

 

CharonY, Thank you very much. Good info.

[Ringer]

Macro-evolution isn't really a scientific term so it's not defined scientifically. It's just what happens given enough time. The problem is that when people use macro-evolution they will, usually, change the definition to suite what they want it to be to keep their argument valid.

 

 

ok so i will just start by saying mutations (whatever types)=noise ie i smash my keyboard and bunch of random stuff comes up, as opposed to a well written out sentence like this which="information" (it is conveying a message) this is very preliminary i will read more. so mutations just seem to add "noise" if you will NOT new information (like for a functional protein that the wild type doesnt have, if this had actually been observed this would give minor creedence to you know what lol.

 

Your analogy is largely flawed. Our writing system has rules and preset words. If something follows the rules but is not one of the accepted words it will be what you say is noise, and if it doesn't follow the rules it will be noise. Now if there is a mutation there will be no noise, every combination of 3 nucleotides will have an amino-acid pair, barring stop codons. So when there is a mutation in a coding region there is a resulting nucleotide sequence, not useless noise.

(^this is very oversimplified and I know it)

 

ok so basically whenever i read evolutionary biology sites the word "evolution" is used as a general term to encompass one or ALL of the following (it depends on the site,) variation within a kind (like dog has white haired kids black haired kids )

 

This must refer to creationist websites because there is no 'kinds' in biological literature

 

, speciation-ok i dont fully get this one yet but so i wont comment (note that there is never an increase in information here i will read more)

 

Speciation isn't the only kind of evolution or else it wouldn't need its own word, it is one result of evolution.

 

, umm and yeh pretty much anything meaning a change in dna/or genes or whatever (so if i have a kid=evolution lol) and also though...(this is where the tricky bit comes in imo)

 

Again, no that is a mutation. A mutation doesn't necessarily cause evolution, though some do.

 

-to mean origin of life from bacteria or something

 

Again, no. This is abiogenesis, evolution requires life to begin so it cannot be used to explain the origin of life.

 

(note this would take an incerase in "information" NEW properly sequenced dna for NEW proteins which serve a NEW purpose-again this has never been observed (which is why im looking for literature on it)

 

I've given you examples of this and you have ignored them.

 

......so knowing the huge range of the definition of the word makes it easier to read the stuff and take note of when they are just referring to standard stuff which we see all the time (variation)

 

I've said it before, evolution is change in allele frequency over time. That is the definition, and the variation is the short term consequence.

 

and take note of when the meaning switches to that of the never observed one (like when big changes are implied, like bacteria to a fish or something...) so yeah....so i guess all the things that have been observed one might call micro-evolution (variation speciation etc) and its hard to actually name something that has never been observed that said macro-evolution would be when they are referring to/implying origins of life/fish to fish with legs or something lol) but again we would have to actually observe this to rightly call it macro-evolution, as the term is for a process that doesnt exist (or hasnt been observed)...

 

It doesn't have to be observed to be known to be true, though as I have said before we have seen large changes and even seen yeast evolve proto-multicellular behavior. I gave the example that no one has observed an atom, or the smaller parts there-in, but you accept them to be real. There's a contradiction that you still have not got around.

 

also the ecoli experiment (lenksis its on the actual website only 6 pages) starts with "Parallel and convergent changes across lineages are hallmarks of adaptive evolution" so i think this is horizontal gene transfer (unicellular things can swap bits of dna it seems, dont fully understand it yet, just pass em right through there cell membrane ) again notice the word evolution is used in this context and it would just be referring to micro-evolution if one wished to call it that, but as this is in actual peer reviewed literature itself (not just an overview) it may be deceptive.....also horizonal gene transfer seems to be a way somethings can pass around or "swap" dna that grants them "antibiotic resistance" (in commas coz i dont know the exact mechanism of action behind it yet)...so yeh hope that helps i will read more...

 

Here's a slug that used HGT to start being able to photosynthesize, so it's not only bacteria that utilize it.

http://www.wired.com/wiredscience/2010/01/green-sea-slug/

 

Here's a story of the yeast;

http://www.nature.com/news/yeast-suggests-speedy-start-for-multicellular-life-1.9810

[Ophiolite]

Macro-evolution isn't really a scientific term so it's not defined scientifically.

Speciation and Macroevolution Ernst Mayr, 1982

Punctuated Equilibrium Comes of Age Gould & Eldridge 1993

Macroevolution is more than repeated rounds of Microevolution D.H.Erwin 2000

 

And a few thousand other publications would seem to indicate you are mistaken.

[Moontanman]

hay asinine cretin

 

ok so i will just start by saying mutations (whatever types)=noise ie i smash my keyboard and bunch of random stuff comes up, as opposed to a well written out sentence like this which="information" (it is conveying a message) this is very preliminary i will read more. so mutations just seem to add "noise" if you will NOT new information (like for a functional protein that the wild type doesnt have, if this had actually been observed this would give minor creedence to you know what lol.

 

ok so basically whenever i read evolutionary biology sites the word "evolution" is used as a general term to encompass one or ALL of the following (it depends on the site,) variation within a kind (like dog has white haired kids black haired kids ), speciation-ok i dont fully get this one yet but so i wont comment (note that there is never an increase in information here i will read more), umm and yeh pretty much anything meaning a change in dna/or genes or whatever (so if i have a kid=evolution lol) and also though...(this is where the tricky bit comes in imo)-to mean origin of life from bacteria or something (note this would take an incerase in "information" NEW properly sequenced dna for NEW proteins which serve a NEW purpose-again this has never been observed (which is why im looking for literature on it)......so knowing the huge range of the definition of the word makes it easier to read the stuff and take note of when they are just referring to standard stuff which we see all the time (variation) and take note of when the meaning switches to that of the never observed one (like when big changes are implied, like bacteria to a fish or something...) so yeah....so i guess all the things that have been observed one might call micro-evolution (variation speciation etc) and its hard to actually name something that has never been observed that said macro-evolution would be when they are referring to/implying origins of life/fish to fish with legs or something lol) but again we would have to actually observe this to rightly call it macro-evolution, as the term is for a process that doesnt exist (or hasnt been observed)...

 

also the ecoli experiment (lenksis its on the actual website only 6 pages) starts with "Parallel and convergent changes across lineages are hallmarks of adaptive evolution" so i think this is horizontal gene transfer (unicellular things can swap bits of dna it seems, dont fully understand it yet, just pass em right through there cell membrane ) again notice the word evolution is used in this context and it would just be referring to micro-evolution if one wished to call it that, but as this is in actual peer reviewed literature itself (not just an overview) it may be deceptive.....also horizonal gene transfer seems to be a way somethings can pass around or "swap" dna that grants them "antibiotic resistance" (in commas coz i dont know the exact mechanism of action behind it yet)...so yeh hope that helps i will read more...

 

 

sammy7 why do you continue to ignore the evidence presented to you and continue to make the same false claims over and over? Do you think that repeating something over and over makes it real? You have been given reasonable examples of macro-evolution many times. For some reason you refuse to even consider the evidence, speciation has been observed, macro-evolution happens via micro-evolution small changes add up...

[iNow]

It's generally unsuccessful trying to use reason and evidence to rebut the position of a person who arrived there using neither.

[immortal]

hay asinine cretin

 

ok so i will just start by saying mutations (whatever types)=noise ie i smash my keyboard and bunch of random stuff comes up, as opposed to a well written out sentence like this which="information" (it is conveying a message) this is very preliminary i will read more. so mutations just seem to add "noise" if you will NOT new information (like for a functional protein that the wild type doesnt have, if this had actually been observed this would give minor creedence to you know what lol.

 

 

 

No, wait. This reminds me of the Shakespeare's problem. A monkey is given a typewriter and it is asked to type the word SHAKESPEARE consisting of 11 alphabets. Now if the monkey starts typing randomly it is very unlikely that it is going to type the word SHAKESPEARE at one go or at one single attempt but if we intoduce a certain constraint that if the right alphabets are in the right places then the slots will be set to default and the monkey continues to randomly type for the remaining slotted locations. For example: if the monkey type it as

 

S G I M E Z H U L R F

 

Then the alphabets S, E and R are the right alphabets at the right position so we keep them up and try to jumble the rest. So it is very much likely that we are going to type the word SHAKESPEARE given enough time. Hence evolution works by accumulating good designs. This example might be misleading it looks like as though evolution has some predestined purpose to get the word Shakespeare it was just an example to show that how selection pressures operate to produce macro forms by accumulating good designs.

 

In the above example we can get snapshots of how the word Shakespeare appeared, for example at one point in time it can look like

S G I M E Z H U L R F

 

it may transform into this after some time

S Q U K E W P J A R B

 

Or at the present moment to this

S H A K E S P E A R E

 

 

In this way evolution works by random mutations followed by non-random selections i.e evolution works by cumulative selection i.e accumulation of good designs.

 

And also don't confuse evolution by natural selection with the origin of language and meaningful sentences, it is a different topic altogether and hence your analogy is irrelevant.