Talk:Microevolution

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The article says microevolution only believes in "destructive genetic mutations, which happen to confer an advantage to individuals in a specific environment". If it confers an advantage in a specific environment, how is it a destructive mutation? Constructive vs. destructive is purely determined in relation to the environment.

The example seems to me like evidence that beneficial microevolution is possible. The fact that a person can intentionally turn it into a destructive one by altering the environment *away* *from* the microevolution doesn't change the fact that the organism originally adapted in a beneficial way. The organism developed the resistance to penicillin while in its presence -- obviously a beneficial adaptation. --Dmerrill

I think point is that the presence of the antibiotic is a rare event (for the organism), the fact is that in the most common environment, the adaptation to produce penicillinase is not beneficial. It takes resources that could be better focussed on survival. -- BenBaker

Maybe. Penicillin comes from where? Mold. Is mold common? Yup. I don't know, but I wouldn't be surprised if penicillin-producing mold does constitute a regular environmental stressor for many bacteria, and resistance a useful trait.
That's doesn't speak to my point. My point is that at the time the adaptation happened, it was beneficial. It later became maladaptive, because the environment changed. That is *exactly* the same phenomenon believed to occur by scientists. So adaptive microevolution is possible, even if that adaptation might subsequently become maladaptive. --Dmerril

I agree. the adaptation was beneficial. and if the environment change was common, it would be appropriate to call it a beneficial adaptation. I think you are using a different criteria for naming than the one intended. I believe that the naming criteria is to describe the adaptation by its impact in the most common environment. Not in the rare situation in which the adaptation flourished. But truthfully, I didn't come up with the adjective, and encourage you to edit the original document to clarify it. -- BenBaker

I would encourage you, however, to remember the article should be describing microevolution rather than beneficial adaptation.

I would be happy to, except that I don't understand the concept of microevolution. I can only point out what appear to be inconsistencies in the article. --Dmerrill

I wish I had a link to the article I got the bacterial example from. It did a much better job than I did here. The gist of it was that these bacteria normally produce a substance which protects them against Penicillin, but they have a gene which limits the amount produced. In the resistant bacteria, this limiting gene is "damaged", so they produce much higher levels than normal, allowing them to thrive in the presence of Penicillin. But this comes at a high price, consuming much of their energy and resources, so that in a "normal" environment, they can't compete with the "normal" bacteria and quickly die out. I'll agree that calling it a destructive mutation is indeed relative. -- RussellReed

Talking about whether or not a mutation is deleterious or beneficial to an individual only makes sense in the context of environment. Thus whether or not a mutation is deleterious or beneficial to an idividual can change as the environment changes. Whether or not a mutation is deleterious or beneficial to a species depends on whether it increases the fitness of that lineage - something we cannot predict over the long term because we cannot predict how environment is going to change over the long term. - Safay 20:56, 25 January 2006 (UTC)

The biggest questions I have about this concept is are:

  1. Is macroevolution intended to mean a single big change that happens, or rather a series of microevolutions that when added up result in macroevolution?
  2. Why do the small changes not, over time, add up to a big one?
  3. How many microevolutions do there have to be before it becomes a macroevolution?
  4. Do creationists accept that most microevolutions are going to be harmful, but a few are beneficial?
  5. Do creationists accept that the beneficial microevolutions can replace the original organism (survival of the fittest)?
  6. How, within this theory, is a species defined? As two groups that can not breed?
  7. If so, what about organisms that do not have sexual reproduction (e.g., bacteria)?

Also, the article says macroevolution is a big change in an organism -- do you really mean by that a change in a single generation from one species to another? If so, it's a straw man since scientists don't believe in that either.

I think these issues should be addressed in the article. --Dmerrill

I'd like the concepts of microevolution and macroevolution better related to the debate over evolution. Moreover, I think they are best used as terms that define the debate, rather than concepts in themselves to be disputed.

The theory of evolution, if it is indeed scientifically sound (and almost no one here doubts that), should be able to stand on its own merits without you all feeling you must defend it at every point.

The various articles which present alternatives to evolution, however outlandish or zany they seem to you scienntists, require merely a link or two each to the accepted science.

-- Ed Poor


I didn't intend to dispute them, although I might somewhere other than Wikipedia. I only presented questions that came up naturally while reading the article. Any article on a theory should include common criticisms and the theory's answer or refutation or explanation.

I agree that a discussion of how these concepts relate to evolutionary theory would be a good thing. But as I said before, I don't know this theory, so I can only ask questions, which imho is an important way to make an article better. --Dmerrill

slrubenstein what was here before was more correct than what you replaced it with -- Please reintegrate the factual portion of what you placed here. In general please try to add content to an article instead of replacing it with your own views -- makes everything easier for everybody. :) --maveric149

I revised the revert in a way that I believe keeps those parts Maveric149 consider accurate. Nevertheless, the earlier version was at times redundant and inconsistent. My goal was to continue ridding the article of inaccuracies while fixing the style. SR


From primates to humans? Are humans now something besides primates?

I still don't understand what microevolution is. How about:

  1. explain what microevolution is
  2. shed some light on the evolution vs. creationism debate

In particular, I would like to understand the importance (if any) of microevolution within neo-Darwinism, i.e., standard evolutionary theory. Only after that would I even be interested in reading about what anti-evolutionists think -- despite my owen religious views. Ed Poor, Tuesday, June 11, 2002

Ed, can you explain a bit more what you do not understand? Of course this article should be clear enough for lay-people, but I thinkm the opening definition is awfully clear. What is not clear about it?

I also do not know what more you want on the evolution/creation debate -- shouldn't that be a different article?

Of course, the article itself assumes that people understand what "evolution" means but there is a separate article on that that goes into a lot of detail that I do not think needs to be included here. slrubenstein

I propose that we combine the microevolution and macroevolution articles into one article. From what I've studied, there is a theory that macroevolution occurs by different mechanisms than microevolution. These terms only make sense within that theoretical framework. If someone believes that "macroevolution" and "microevolution" occur by the same mechanisms, then they don't bother to use those two terms...it's all just evolution to them.

Further, this is a real debate among real biologists. The creationists will latch onto and distort anything that they can; their views should just be a footnote of the article and not the meat of it. I'm studying this issue right now in one of my classes and will be happy to contribute more in a month or two after I've read everything that my professor has recommended. --adam

[edit] The term evolution

I think I'm seeing the word evolution being used with two different meanings, and I think these meanings are sufficiently different that they should be highlighted rather than glossed over. They are NOT synonyms.

  1. Evolution means ANY genetic difference between an organism and its descendant.
  2. Evolution means the theory that new species can and do come into being, purely as a result of natural forces

In sense #1, Creationists would clearly be wrong if they said "no evolution ever takes place", because there are readily observable genetic differences.

In sense #2, Creationists would not necessarily be wrong if they said "no evolution ever takes place", because there is no proof that natural forces alone are sufficient to cause new species to come into being.

Indeed the idea that natural forces alone are sufficient to cause new species to come into being is arguably not even a "scientific hypothesis", because there's no way to falsify it -- unless and until somebody succeeds in creating a new species in the laboratory (shades of Frankenstein!). --Uncle Ed 14:04, 7 Oct 2004 (UTC)

Oops! I'm wrong, of course {slaps forehead impatiently}. If someone creates a new species, that's creation by design, not naturalistic evolution. So how could we possibly ever "falsify" the theory of evolution? What kind of experiment could we perform, the results of which (if they turned out a certain way) would prove evolution false? --Uncle Ed 14:10, 7 Oct 2004 (UTC)
If you identify a single anatomical feature, of any species, that could not have evolved gradually (that is, the entire subsystem had to have appeared all at once or not at all) that would falsify natural selection as the only evolutionary mechanism theory. Many people have looked for examples of such features but none proposed so far have been unexplainable by natural selection (ie, a fraction of an eye still sees better than no eye at all, and tiny "wings" on an insect aren't great at controlling flight but might be good radiators). Saucepan 15:33, 7 Oct 2004 (UTC)
The theory as you stated cannot be falsified, since that's a very general statement and requires a very high burden of proof. The theory of evolution as understood by modern science can, of course, be falsified. There have been some significant challenges, for example the problem of genetic load was a major one for evolution and there is some debate as to how well-settled this question is. Graft 15:36, 7 Oct 2004 (UTC)

Graft, if I understand you right you are saying that one theory cannot be falsified, but that a second theory can.

  1. The theory of evolution as understood by modern science can be falsified; but,
  2. the idea that natural forces alone are sufficient to cause new species to come into being cannot be falsified.

Before I go off half-cocked, please confirm whether I have restated your position correctly. And BTW is this the position of biologists generally as well? --Uncle Ed 16:50, 7 Oct 2004 (UTC)


I wouldn't say that (2) cannot be falsified. Just that it would be enormously difficult to do so. The position of biologists and scientists in general is that there are naturalistic explanations for all phenomenon. This is a fundamental assumption of science; to assume otherwise would be to forestall the possibility of further scientific inquiry. See the long discussion on Talk:Intelligent design for more. Graft 17:45, 7 Oct 2004 (UTC)

I agree that this discussion belongs on a page about the debate between creation and evolution. But here I am getting sucked in anyway. The confusion here stems from the difference between deductive and inductive reasoning. Biologists do not need to do experiments to show that speciation is an evolutionary process, because a preponderance of evidence supports an evolutionary explaination and no other; this is called inductive reasoning and is a valid scientific process, and is used especially often in evolutionary biology, geology, planetary science, astronomy, and cosmology. All the evidence supports a hypothesis that evolution is what gave us the diversity of life on earth. None of the evidence contradicts it. Safay 18:33, 29 January 2006 (UTC)

[edit] Primrose

Hi Duncharris,

Why did you delete the example of the primrose plant?

Regards, --Jason Gastrich 22:03, 23 November 2005 (UTC)

Hello Jason. Can you offer a citation for that please? specifically we are referring to "the primrose plant spontaneously producing another species of primrose plant". Your wording doesn't make much sense to me as a biologist. — Dunc|☺ 22:09, 23 November 2005 (UTC)
Interesting choice of citation from Jason. i think we all assumed he was discussing mutations in Primula specifically the well documented allopolyploid species known as the Kew Primrose (Primula kewensis) created by Digby (The citology of Primula kewensis and of other related Primula hybrids. (1912). Ann Bot 26, 357-388) from a cross between Primula verticillata and Primula floribunda. After a rare polyploidization event the initially sterile hybrid led to a fertile allotetraploid, the new species P. kewensis. I think we agree this is an example of macroevolution. However, Jason did not cite this example. His cite is for evening primrose which is NOT a primrose it is Oenothera. Actually, that example sounds like it is a good example of microevolution, although there needs to be more clarification in the edits. From the source that Jason cites: "Hugo De Vries discovered new forms among a display of Evening Primrose Oenothera lamarcklana growing wild in a waste meadow............. The name "mutation" was given to his new method of producing new species and varieties (cultivars) which he showed to arise unexpectedly." David D. (Talk) 23:37, 23 November 2005 (UTC)


[edit] Definition of Macroevolution

I think the definition of macroevolution provided here is incorrect. We don't need the two terms macroevolution and microevolution if they do not refer to different processes. This article currently states that the processes underlying macroevo are the same, i.e., allele frequency changes. The Modern Synthesis does assert that a change in allele frequencies is the only kind of evolution that really occurs. This is what Eldridge and Gould and other supporters of the idea of macroevolutionary processes disagree with. Thus there is a disjunct in what evolutionary biologists agree upon as the scope of evolutionary process. (An aside: This disagreement is what the creationists latch on to and make wild claims about there being a crisis in evolutionary biology, that we don't understand macroevolutionary process and thus must invoke a creator.)

Macroevolution refers to processes that occur above the level of species. The Neo-Darwinists will assert that no such processes exist, and thus we truly don't need the two words micro- and macroevolution. The people who do support macroevolution will assert that it involves processes that cannot be explained through population genetics. Thus, in an article about macroevolution and microevolution, we should use the definition that the macroevolutionists use, and explain the existence of the controversy over the subject.

I think this further highlights the need to combine the two articles, macro- and microevolution.

What do you all think of this? If no one responds in a week I'm just going to go ahead and do it and see if that bears out.

Safay 06:52, 28 January 2006 (UTC)

If you can give me some idea what processes you're talking about, I'd be more inclined to agree.
By analogy, consider anything at all. Take ice crystals - fabulous in form, certainly, but ultimately whatever higher-order structure we observe is dictated by simple fundamental principles. How those principles manifest in a macroscopic scale is perhaps surprising, but there's not really much else going on. (This is probably a bad analogy because I don't know any physics or structural chemistry, but just use your imagination). My point is, big, sweeping movements in history must be composed of small, incremental changes. And what's evident at that scale is, essentially, what we're calling "microevolution". What else could there be? Graft 07:16, 28 January 2006 (UTC)
Obviously you cannot really have evolution above the species level, but you can study evolutionary change above the species level. At the same time, while a lot of macro is just micro over a larger time scale, speciation can be caused by nonevolutionary processes - like polyploidy, which is believed to be an important factor in plant evolution (though less well studied in animals). At the same time, I am unsure what changes you are proposing. Guettarda 07:46, 28 January 2006 (UTC)
How is polyploidy 'non-evolutionary'? It's a mutation is if not? -- Ec5618 12:48, 28 January 2006 (UTC)
Does it change population gene frequencies? Guettarda 15:16, 28 January 2006 (UTC)
New mutation event, just like gene duplication. After all, any aneuploidy has to propagate in the population and fix just like any other mutational event. Graft 01:23, 29 January 2006 (UTC)
Yeah, I suppose, my mistake. Talking with my brian switched off. Guettarda 02:32, 29 January 2006 (UTC)
A couple of quick corrections: Polyploidy is euploidy, not aneuploidy. The mutation that creates a polyploid is a somatic nondisjunction that instantly creates a new species. You don't have to have selection to get it fixed in the population. Instead, the new species now competes with the old ones. Ted 03:39, 1 April 2006 (UTC)

[edit] Theory/Hypothesis

Why was my contribution on Micro/Macroevolution reversed? Macroevolution is a speculated hypothesis while Microevolution is a proven theory. Neither Macro nor Microevolution have enough evidence to be taken as a scientific law. And because Wikipedia allows later changes to be made to an article thne we should list micro and macroevolution as it is currently, theory and hypothesis. -Teofil Bartlomiej 20:41, 17 January 2007 (UTC)

  • "Scientific laws" are generalisations, usually from the nineteenth century, and not really part of the scientific hierarchy.
  • Microevolution and macroevolution are scales of study, not hypothesis. Calling them either theory or hypothesis is wrong. Both are observations. The mechanisms of evolution are the hypotheses and theories - some can be considered at microevolutionary or macroevolutionary scales.

Your additions were inaccurate. You should not insert factually inaccurate material into Wikipedia articles. Please don't do that. Guettarda 21:09, 17 January 2007 (UTC)

What do you mean? By what sources can you conclude that microevolution and macroevolution are not how I listed them? I have my sources from Exploring Creation with Biology, Module 9 (just because it is a creationist book does not make it any less reliable). —Preceding unsigned comment added by Working for Him (talk • contribs)
To begin with, there is no such thing as a "proven theory". Please see the scientific method article. The scientific method does not allow for "proof". So any source which speaks of a "proven theory" is obviously unreliable. There is no hierarchy from theory to law...theory is about as good as you can get. Try reading Karl Popper's Conjectures and Refutations.
Broadly speaking, theories and hypotheses are mechanistic. They must be testable. The terms macroevolution and microevolution are levels of study. They are not hypotheses. Studies which look at evolutionary change within species are often described as being microevolutionary. Studies which looks at changes within larger groups (genera, families, etc.) are often described as macroevolutionary. These are not hypotheses. If you are studying changes in allele frequency within a single species, your study is microevolutionary. The fact that you are working on a single species isn't a hypothesis, it's an assumption. Similarly, if you are studying two sister species, the fact that Species A and Species B are separate species is the assumption that makes the study macroevolutionary, not a hypothesis of the study. That such a thing as species exists is an evolutionary theory, but it isn't really something you can call "macroevolutionary" or "microevolutionary". Guettarda 05:24, 18 January 2007 (UTC)

[edit] First occurance of Micro Evolution

This thread http://groups.google.com/group/talk.origins/browse_thread/thread/38df9a9a127281a8/cea310284f6d201c#cea310284f6d201c states that Micro Evolution occured in the Oxford English Dictionary is from 1911, citing the American Naturalist v. 45, p. 256. The first for "macro-evolution" is Dobzhansky's "Genetics & Origin of Species". Was Micro coined before Macro? TongueSpeaker 20:49, 15 April 2007 (UTC)

The author of phrase "ME" had a specific concept that he used "Micro Evolution" for as a technical description. Everybody seems to have their own defenition of the word such as "small changes", "change below the species level" etc. Imagine we all just have our own defenition for the technical jargon phrase "signal-to-noise ratio". It has a specific meaning which represents a concept and thus you can't just hijack the phrase and associate it with a different concept than what Shannon had in mind. The same logic extends to "Micro Evolution", everybody seemingly knows what it means but nobody even bothers to cite the author and what concept did he wish to convey with it.TongueSpeaker 11:21, 29 May 2007 (UTC)

[edit] Micro-Reductionist vs. Macro-Holistic

How is Marcroevolution not Reductionist in that it is mostly, if not entirely, dependent upon Mircoevolution? Why is this supposed dichotomous distinction even trying to be postulated? --Carlon 16:02, 16 August 2007 (UTC) To call Macroevolution "holistic" implies that there is some kind of "magic" not present in Microevolution that must happen for Macroevolution to be possible. In reality the difference is only one of degree: given enough time, Microevolution IS Macroevolution. There is nothing holistic going on; the whole is no more or less than the sum of its parts. It's like saying Macro-counting is holistic and Micro-counting is reductionist because we can observe the numbers between one and 10 but nobody's ever been observed to count to a trillion. 71.228.211.57 (talk) 15:03, 16 April 2008 (UTC)

[edit] Creationist shibboleth, no more, no less

I am mildly astonished that Wikipedia even has this article.

"Evolution" is change in allele frequency over time in a breeding population. No more, no less. It is the unified field theory of biology, and it parsimoniously explains everything from antibiotic-resistant bacteria to the beak of the zebra finch to humanity's triumphant conquest of this planet.

"Microevolution" and "macroevolution" are shibboleths used by religious cranks who object to the philosophical implications of certain empirically verified facts from the fields of biology and zoology. Worse, they are casuistries, created to deceive the ignorant.

Is it too late for a VFD?