I’ve read some info recently regarding how microevolution is a proven fact and an undeniable phenomenon in nature. Macroevolution on the other hand lacks conclusive evidence to support it as scientific FACT. So, we have this split from the term “evolution” since the 1860’s, but if microevolution is a proven scientific fact, why is the word evolution still regarded as theory? Is it because macroevolution hasn’t been accounted for?
Could an evolutionist argue that the validity of microevolution can prove the case for macroevolution despite that the former is based on reductionism and the latter is holistic?
Does the lack of conclusive evidence for macroevolution justify the arguments held by advocates of the intelligent design theory? That question speaks for itself as it revolves around the same idea that any unexplained phenomena in nature should and must be given a cause by religious folk, and that cause is a deity. This leads to another question: If, under the assumption, the lack of conclusive evidence to support macroevolution suggests the concept of intelligent design, then what is the evidence to support intelligent design aside from there being no conclusive evidence to support macroevolution?
Notice how I used the word “conclusive” before the word “evidence.” While I recognize that there is substantial evidence to support the claim of macroevolution, there exists nothing as of yet to solidify that claim as the evidence for microevolution has done.
So, I’m hoping for some good answers to these questions (highlighted in red). I’m also hoping this thread will not evolve into the realm of a religious argument.
The theory of evolution is a theory because it is a model or description of natural processes, encompassing many such processes in a single elegant idea or set of related ideas. That’s what the word “theory” means in science. It it not fact not because of any deficiencies in it, but because a theory in science is never fact; facts are what theories explain.
Macroevolution IS proven fact. There is no way to account for the fossil record, which clearly shows a change in the species mix on earth over time, except to say that the descendants of earlier species have become newer species. The theory of evolution is not a theory THAT this happens, it is a theory of HOW this happens, namely through natural selection, modified since Darwin’s time by inclusion of genetic knowledge he lacked, and by recognition of punctuating events such as mass extinctions that vary the rate of evolutionary change.
That theory is not proven fact because theories never are. They are always held tentatively and always subject to being replaced, or at least modified, upon acquisition of new data. Darwin’s theory has already been modified since his time, and it is always possible that some completely different model of evolution will someday replace it. And virtually a given that further changes short of complete replacement will take place.
Ahh, pardon my misunderstanding then. I was confused before with all the intelligent design advocates claiming evolution was bogus, non-existant, and other wild assertions like mankind could not have descended from apes because “God” created man. [size=75](…and yet, in the biblical creation story, animals were made before man…)[/size]
I never saw it that way… sometimes I find myself relearning things I’ve forgotten from school years ago; this is one such case. I was oblivious for a number of years that a “theory” wasn’t an explaination of proven fact as you’ve revealed, but rather an idea waiting to be proven. Thank you very much Nav!
So… the intelligent design advocates have posited that since Darwin’s theory of HOW evolution unfolded is unacceptable (i.e. natural selection), they have come to believe that “God” having created the world and set the process of evolution according to his design is more acceptable. Is that about right?
So I guess my next questions are… What’s wrong with Darwin’s theory that has led creationists to come up with the concept of intelligent design? Was it that he was unable to explain how variation might arise or be altered over generations in the course of natural selection? Or is it that his theory posits a origin of man that religious folk are uncomforatble with?
Also… Why the debate between micro and macroevolution? Can’t we just pick one and be done with it?
I would imagine it would be the other way round. The creationists have a theory of the world, its origins and how Man came to be. Darwin’s theory contradicts this, and is therefore wrong. I don’t believe it is because of an honest appraisal of the evidence in either case.
Of course, we all come to every new idea with considerable baggage and engage in this kind of thinking every day. I think Nietzsche’s “On the Prejudices of Philosophers” in BGE talks about this.
There is no debate. Creationists came up with the idea of intelligent design to attempt to allow creationism to be taught in schools under a different label. Here’s a link if you want more info on it, very informative.
Wow. dd, that was a wonderful contribution to this thread… I watched it (all 117 minutes!) and not only found it very informative, but funny, witty, entertaining, and addictively engaging (I could not take my eyes off of it).
Because of this lecture by the imminent Ken Miller, I have learned more about evolution and the ludicrous notion of intelligent design than I ever sought to seek out. Thanks again!
Read down this timeline, and when you get to references about the hominid line and human evolution, stop; you’ve gone far enough then. Observe that by the time you get to this point, none of the species you’re reading about were in existence way back when the first life appeared, or for that matter even 100 million years earlier.
We have a species mix today that is completely, radically different from what was on the earth 200 million years ago. Almost none of the species that are alive today were alive then. Almost all species that were alive then are extinct now.
Evolution is the only way to account for this change that makes any sense.
I think part of the problem is that the language has been co-opted.
If you look at the scientific literature, there is no mention of ‘micro’ and ‘macro’ evolution – it is just ‘evolution’. But, when the critics of evolution starting coming out of the woodwork again (after having been on the down-low since Scopes trial) the scientific community pretty much ignored them. They were crazies, right? So, engaging in a dialouge with them would only validate their way-out-their point.
But, these people weren’t crazy. They were intelligent and devoted people who were able to make an argument and build up a base while we fiddled. By the time educated biologists started to take the issue as a serious threat, the anti-evolutionists had created a very strong language that would make the debate incredibly hard to win.
If you can’t say what you mean, it is damned hard to mean what you say.
My pleasure. When comparing the arguments of intelligent design or creationists with that of evolution…well, there is no comparison.
I’m about to embark on Origin of Species by Darwin, as well as Darwin’s Dangerous Idea by Dennett, and have already read Blind Watchmaker by Dawkins.
Soon I’ll make a post regarding the affect of this knowledge on philosophy, because, just like religion, there are some implications with this newfound fact.
Sagesound, if you’re interested in the histrory of the intelligent design movement, as well as many other aspects of the debate, the ruling from Kitzmiller v. Dover is a fascinating read. It discusses the evolution (if I may use the term) of creationism through creation science into the new intelligent design theory, the validity of the arguments made by the intelligent design theorists, and the acknowledged underhandedness of the tactics used to insert intelligent design into mainstream science.
The problem seems to me that, while the creationists arguments may be weak, people who sense that evolution is the better model have not well explained the weaknesses of stasis and radical change. It seems to me that the objections to the conventional mechanisms of natural selection and genetic drift are legitimate.
This had bothered me for a couple of years until I found an additional mechanism which could help explain stasis and radical change.
The evolutionary mechanism of germ line embedding of retro viruses significantly alleviates these problems.
Documentation on this phenomenon is significant on virology web sites and they have even identified a viral encoding gene for the protein Syncytin which makes possible the attachment of the placenta in the vast majority of mammals.
If you want to read more on this matter you can read my post at:
There is another explanation for periods of rapid change (specifically the periods you reference in your linked post). Rapid environmental change increases selection preassure, thereby encouraging more radical changes. Furthermore, a massive die-off should be followed by an explosion of diversity because of the number of evolutionary niches that have been left vacant. Basically, any event which results in increased adversity or opportunity should result in rapid large-scale changes to organisms that are affected.
This is not to discredit the theory you present, but to point out that the explanation can be much simpler.
I agree with your post and my reply is primarily intended as a shades of gray comment.
Most of the concern revolves about genetically complex organisms. While it is true that natural selection will increase selection pressure towards more adaptable species initially, the question becomes: what is the likelihood that genetic encoding changes, on the order thousands, for a genetically complex organism, are likely to take place in such a geologically short time? Historically, isolated genetic changes take place over a long period of time. What would trigger these chemical changes, which are required before natural selection could make any difference?
Thanks for your response and especially for looking at my post.
Hi Ed. I read the post you linked to and found it interesting, but just want to say a couple of things.
Firstly, “viral” DNA is - as I understand it - inert: that is to say, it is involved in neither protein creation nor the sequencing of protein creation. Like most other DNA, while viral DNA’s position in the genome may indirectly affect the operation of “active” genes, it appears to serve no direct function itself. The idea, therefore, that viral DNA can account for the present morphology of human beings or other animals seems to be largely without empirical support.
Secondly, large changes in the genome that radically alter the manifest nature of an organism are almost certain to be harmful rather than beneficial. There are ways of avoiding this in your theory - by presuming that active viral DNA only enters the genome in small pieces at a time (thus not creating a change in the organism that is likely to be significantly harmful), or that large chunks of inert viral DNA are added to the genome and then gradually co-opted in beneficial ways by the organism through the process of mutation and natural selection - but that just leaves us with the same dilema we had at the beginning: we’re still relying on the small accretion of incremental changes in the genome to account for macroscopic changes in the morphological nature of organisms.
I certainly think your theory has merit: maybe many of our active genes originally did have an exogenous, viral origin and it would certainly be exciting if that was discovered to be the case. However, even if that is so, I still find it far more likely that we evolved through small, constant changes in our genome rather than through rare, big changes that originated with the introducion of viruses (virii?) to our genome.
How would you define a “geologically short time”? 10,000 years is the blink of an eye geologically, but it’s still - depending on the organism - likely to accomodate thousands of generations, more than enough to bring about large scale changes in a species if the selection pressures are severe enough.
There is natural variation amongst the genes of organisms to begin with: selection pressures can favour a number of wildly disparate morphologies (say, the difference between a great dane and a chihuahua) without substantial changes in the genome. Also, there is a base rate of mutation in any strand of DNA: as I posted in a thread in the Religion forum, I believe I read that the mutation rate (that is, an unfaithful transription of the DNA sequence) occurs between 20-40 times per billion base pairs of DNA. The mutation rate however varies from gene to gene to a predictable degree, as we find with genetic disorders:
Let’s presume a there’s a population of 1,000 organisms, each with a DNA sequence consisting of 1 billion base pairs and that the rate of mutation is (to use the low-end estimate) 20 occurances per billion. In the first generation (presuming the population stays contant) there are 20,000 seperate instances of genetic mutation in the gene pool. If I’ve got my math right here, by the second generation there will be 400,000 seperate instances of genetic mutation, by the third there will be 8 million and by the tenth there will be more than a million billion. Now obviously the genome is finite and many of the same mutations will occur many, many times (a la genetic disorders in humans) but the point is that genetic diversity accumulates extremely rapidly and that any favourable gene will quickly find its way through the population.
I think that between the inherent genetic variation within a species, the mutation rate and the right selection pressures, there is more than enough evidence available to explain how “chemical changes” can account for the punctuated evolution of species we find in the fossil record, without the need to invoke a more drastic explanation (such as viral DNA).
Interesting post, especially covering the point of genetic disorders. Of course, more than a million billion is a huge number… a million billion by definition is one quadrillion, which is one thousand trillions. Of course, it’s funny sometimes how we as human come up with numbers to which we have no physical proof of measuring… the world population will hopefully never breach the one trillion barrier (that would be insane, but we would know what a group of one trillion looks like). Could we even in our wildest dreams conceive what a googolplex looks like?
I’m not sure I understand your request as I’m not a scientist. I’m assuming you desire an answer like this: For example, microevolution would be useful in explaining HOW a red and a white flower produced a pink one. Macroevolution, in example, would be useful in explaining HOW we evolved from primitive apes through the fusion of DNA. Does this touch on what you were wanting to know?
not really, sagesound, I’m sorry…
The problem of this entire discussion is that nobody really knows what we’re talking about. In the end we could have totally different ideas about what exactly micro- and macro-evolution is and thus have a meaningless conversation.
Since the theories we’re debating are scientific ones, it’d be useful if we could have some scientific basis for micro- and macro-evolution and go from there.
I was confused before with all the intelligent design advocates claiming evolution was bogus, non-existant, and other wild assertions like 
I was oblivious for a number of years that a “theory” wasn’t an explaination of proven fact as you’ve revealed, but rather an idea waiting to be proven. Thank you very much Nav!