I’ve heard some people state that they believe in microevolution, but don’t believe in macroevolution. I am baffled by this stance and am hoping someone who holds this belief can explain it to me.
The problem I percieve is determining where microevolution ends and macroevolution begins. For example, let’s take a finch’s beak (because that’s what the last person I read proclaiming this view used). As I understand it, microevolution is accepted as accounting for changes in the size of said beak by the microevolution believers.
Well, how big does the finch’s beak have to get before the bird is not a finch anymore? What if it’s wings also become larger, along with the beak. What happens if it grows so large that it cannot mate with the smaller variety of finch? Does microevolution propose some limit to the degree of change that can occur? If so, what is the limit and how is it determined? If not, where is the line between micro and macro evolution?
Typically, microevolution is everything up to and including speciation. Thus, it encompasses pretty much all of population biology and genetics, adaptation, and, of course, speciation. Macroevolution concerns itself with the evolution of higher groups, that is, how do we get from species to Genera, Families, Orders, etc. (assuming one buys into Linnaean classification, which I don’t particularly care for, but that’s another topic). One macroevolutionary theory, as an example, is that of species selection, which basically postulates the extention of natural selection’s workings on individuals to a population level.
In short, microevolution strives to explain why the finch’s beak is as it is, and why this finch’s beak is different from that finch’s beak. Macroevolution strives to understand why a finch is different from a warbler, or why both are different from a pelican, etc., as well as the origins of these various taxa.
There was no such term as “micro-evolution” until the shyster “Creation Scientists” realized that even they could not cover up the factual and observed evidence of evolution (from species evolving traits based upon their environment to speciation itself observed), so they changed their tact to say, “Well, sure this stuff happens, but that is not evidence of what you heathens are talking about!”
This grasping at straws assumes that the two things are not related, that one thing is not simply more evidence to throw on the mountain of evidence we already have for evolution in general.
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Mmm. While I concur for the most part with what has been said to date, I’d suggest that there might be a legitimate use for the distinction. Microevolution being considered as adaptation within a species contrasts with macroevolution dealing with speciation and phylogenesis. Granted that allowing one and arguing against the other on the basis of specious Biblical interpretation is folderol, the distinction may be significant in understanding the mechanisms through which evolution works. At what point does something become a new species? A new genus or family? Presently the definition above species level is pretty subjective, as is that for extinct species. What level of differentiation constitutes speciation? How can we determine that level?
Because I really would like somebody to explain where this wall is that divides one species from another. And why, given time, small changes wouldn’t become bigger. (or is the only reason macro evolution hasn’t happened is that the world is 5000 years old.)
(I saw this really great show {wish I knew where to find it again} about spiders. This woman spent years studying and catologueing thousands and thousand of one species of jumping spiders that lived in one particular feild. And some of the spiders lived in the shady part and some of them lived in the sunny part. And gradually they had developed slightly different strategies for hunting based on the differing risks ofthe sun and the predators. At this point the sunspiders and the shade spiders can still mate and produce fertile offspring (ie they are still one specices). But the mixed children tend to be no good at either strategy. They tend to get eaten. So there won’t be very many mixed spiders reproducing. And the differences will become more pronounced. And eventually they won’t mate at all. And they will be two different species. Of course this will take many generations. And it will probably not impress somebody who wants to see a fish give birth to a racoon.)
[Ryan attempts his best JW impression]
The Bible tellls us that God created many different kinds of animals. It does not tell us what exactly what these kinds comprise, whether they refer to different species or to different categories of species. However, the Bible is very clear that the Creation of these kinds was performed by God Himself, not by blind, random forces. Since the Creation, no new kinds have appeared, and all animals have stayed within their kind. During the Flood, Noah took at least two animals from each kind, and all of the animals of all the kinds that are alive today are descended from the animals of that kind that were on the Ark. The information needed by a particular kind was encoded in their DNA during the Creation, and all of that information has remained, even when not used. For instance, if we breed some finches with wings too small to fly, the finches still retain the information of their kind, and their descendants can be bred to fly again. However, this information can not be created; it would not be possible to breed dogs to fly, since the dog’s kind does not have the information to fly. Only God can supply this information.
[/Ryan attempts his best JW impression]
Of course, in this formulation there is nothing to say that all animals aren’t the same kind.
The real problem with this argument is that the concept of species is entirely artificial. It was thrust upon the unsuspecting natural world by Linnaeus back in the mumble hundreds (how’s that for embarassing - I can’t even remember what century he lived in). The working definition of species you hear most often is “if two organisms can breed to produce fertile offspring, they’re in the same species. If not, they’re not.” The problem is, the world is vastly more complicated than that. There are endless examples of organisms where this definition isn’t good.
So what it comes down to is that the dividing line between species (at least in many cases) is arbitrary, and therefore so is the distinction between micro- and macroevolution.
This doesn’t really help you with getting an answer from a creationist, but here is a link to a Mailbag article I did on this topic a little while back:
Heres a answer from a creationist(I believe that god told the atoms what to do and they did it, wether by evolution or whatever.)
Macroevolution is basically easier to say than “developing new information” vs natural selection.
For example growing a human ear on the back of a rat would be macroevolution. Whereas a rat going blind because of a lack of sunlight would not be since its actually losing information. However this is only my opinion of what people argue about it, not what it actually means.
Now please try to stay away from posts like Satan’s as this is not the pit. Though im sure David B will make sure that doesen’t happen.
[quote]
Heres a answer from a creationist(I believe that god told the atoms what to do and they did it, wether by evolution or whatever.)
Macroevolution is basically easier to say than “developing new information” vs natural selection.
For example growing a human ear on the back of a rat would be macroevolution. Whereas a rat going blind because of a lack of sunlight would not be since its actually losing information. However this is only my opinion of what people argue about it, not what it actually means.
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Well, at least you admit that it’s your own definition, but you aren’t going to get very far discussing issues with other people if you define words completely differently than they do. Imagine engaging in a three hour debate over the existence of Santa Claus only to discover that your opponent calls his dog Santa Claus, so of course he exists!
Evolution is a change in allele frequency over time. Macroevolution is evolution at or above the species level. Growing an ear on the back of a rat is a fancy bit of laboratory research. I have no clue how it was done. If it was done via gene splicing, it’s definitely evolution, albeit artificial. A rat going blind because of lack of sunlight is not evolution at all, anymore than a human losing his arm in an automobile accident is evolution. It is a phenotypic change; the genes still stay in tact. The rat’s offspring will still be able to see.
Gee, that’s funny, when I first heard these terms a few years ago, speciation was absolutely positively definitely considered to be within the realm of macroevolution.
Perhaps what happened was this:
[ol][li]Some Creation “Scientists” coined the term “macroevolution” to mean speciation, so that they could shout “we admit that microevolution happens, but there’s no evidence that macroevolution has ever happened!”[/li][li]Somebody showed them the Observed Instances of Speciation FAQ at the talk.origins archive.[/li]The Creation “Scientists” moved the goal posts so that only the creation of a new genus would be sufficient for macroevolution. Thus they could continue to bark, “There’s no evidence that macroevolution has ever happened!”[/ol]If an instance of “genus-ation” is ever observed, they will always be able to move the goal posts again and claim that macroevolution requires the creation of a new family.
Thanks, everyone for confirming what I was thinking. I’ve been reading a lot of Gould, Dawkins and Weiner (and of course, this board) lately and in doing so I realised that I could not imagine how one would draw the line between micro and macro evolution.
I was curious as to how a microevolutionist would explain his/her position, but since no one has and since nearly everyone posting to this thread has said what I was thinking, my guess is that there is no way to reasonably separate micro from macro evolution. To say that micro evolution includes everything except speciation assumes a clear cut line indicating a speciation point. With the deliniation of species being a man-made and fairly arbitrary division (not to mention observation of the real world), there doesn’t seem to be any such clear line.
OK, well, thanks again everyone. I still don’t understand how anyone could hold the “micro evolution is true but macro isn’t” point of view, but then again, I don’t understand the Flat Earth Society either.
Well, according to my sources, that is not the case. Speciation is essentially the dividing line between micro- and macro-evolution. Differential survival of species is certainly within the realm of macroevolution, however.
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And Satan wrote:
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It seems that a number of posters (or at the very least, Satan and tracer) are under the mistaken impression that the differentiation between micro- and macro- evolution is a creationist invention. This is not the case. More than likely, so-called creation scientists simply don’t understand the difference between the two, so they jumble up the meaning and intent of said differentiation. I would like to point out that the concept of species selection (a strictly macroevolutionary theory) that I mentioned earlier was introduced by Gould, et al. I am sure no one here would disagree that Gould is a devout evolutionist!
The differentiation (and the debate as to whether or not there even should be such a differentiation) has more to do with philosophical ideas between evolutionists than it has anything to do with creationism. As such, Lucky, you are more likely to hear from those who study evolution than those who do not.
At heart is this basic question: are the processes that result in speciation sufficient to explain the differentiation of higher groupings? Judging by the posts received so far, most people are under the impression that yes, they are. Many who study evolution, however, are not so sure.
When I get home (I am posting from work), I can provide more referencial information. In the meantime, I can leave you with these definitions from “Phylogenetic Patterns and the Evolutionary Process: Method and Theory in Comparative Biology”, by Niles Eldredge and Joel Cracraft (1980) (That’s the same Eldredge who, along with Gould, developed the theory of punctuated equilibirum, by the way):
“…Microevolution is, perhaps, best defined as change in gene content and frequency within populations, and macroevolution is defined as change in species composition within a monophyletic group in space and time, best thought of, perhaps, as a process of differential species origination and survival within monophyletic taxa.” [pp 15-16]
And whether the species concept is artificial is another debate in itself.
Huh. Well, it looks like I’ll have to eat my words now. You’re right, Mauve Dog, the term macroevolution was definitely not coined by Creation “Scientists.”
No, there are animals with genes that makes them blind. And this is evolution. I don’t see how this is not gaining information. If the resources that go towards growing eyes are better spent somewhere else, and one animal has genes that tell it to not bother growing eyes, has not the informaition that eyes are a misuse of resources been encoded in that animal’s genes? Saying that the loss of attributes that are detrimental an animal is a loss of information is like saying that when Michealangelo removed the portions of marble not in his statues, he was destroying information.
In my definition I meant that thats what ive seen most creationists point out not really knowing what it meant.
Also the loss of information, I said that wrong, I meant it did not gain any information. The proof for me to believe in evolution would occur over such a long time period that its never going to happen which is why this debate drags so long. Evolutionists can say they are right but they don’t really know untill those millenia occur(and you wont know then because you will be dead) Untill I see new information causing a actual new something like a eye for me evolution is unproven and its only value is in debating and saying “you have no idea how evolution works”.
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