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Macroevolution vs. microevolution


Where is the line usually drawn between macroevolution and microevolution?

I thought that, although similar processes govern both, the line was at the species level, with macroevolution being changes at the above-species level and microevolution being changes within a species (something like changes in allele frequencies). (So it's a question of timescales?)

However, I heard someone talk about microevolution among different species of Drosophila, specifically referring to copy number variation. Was the choice of "microevolution" to describe this process (more likely) due to the similarity between Drosophila species or the type of change in the gene? Or at this level, is the distinction rather arbitrary?


Let's start with a word of caution: on the internet, the terms macroevolution and microevolution (especially together) are usually used primarily in creationist rhetoric. As such, it is usually best to avoid them, especially when talking to a lay audience. The main mistake creationists perpetuate when thinking about micro-vs-macro evolution, is that the two are somehow different and distinct physical processes. This is simply not the case, they are both just evolution. The scientific distinction between the terms, comes not from the physical world around us, but from how we choose to talk about it. When a biologist says "microevolution" or "macroevolution" they are actually signaling what kind of questions they are interested in asking, or what sort of tools they plan on using.

Verbal and empirical theories

In verbal and empirical theories, the micro-macro distinction is usually one of timescales. A person in the macroevolutionary paradigm, usually asks questions above the level of individual species, as Evolution 101 writes (emphasis mine):

instead of focusing on an individual beetle species, a macroevolutionary lens might require that we zoom out on the tree of life, to assess the diversity of the entire beetle clade and its position on the tree.

Empirically, macroevolutionary answers to these sort of questions are usually ones that don't have access to detailed evolutionary histories or direct experiment. Instead, the method tends to be ones that use geology, fossils, and back-inferences from broad differences/similarities of existing species. As such, most macroevolutionary theories tend to be descriptive, instead of predictive. Most of paleontology can be classified under the macroevolutionary paradigm.

If someone explicitly says that they are looking at microevolution then this usually refers to a contrasting methodology that tends to be heavy on direct experimental manipulation. Most importantly, microevolutionists tend to have access to rich and detailed evolutionary histories. As such, it is not surprising that you saw a study that identified itself as microevolutionary while looking at different species of Drosophila. The fruit fly is one of the widest used model organisms, and as such the study you are referring to probably experimentally manipulated populations of fruit flies and collected a rich dataset of genetic changes in the generations of fruit flies that they studied.

Of course, most studies are at intermittent levels, and no this isn't called meso-evolution (except by silly people). If you are not clearly using the macroevolutionary nor the microevolutionary paradigm but still looking at evolution, you would just simply say 'evolutionary' without any prefix.

Formal and mathematical models

For formal and mathematical theories, the micro/macro distinction is also one of methods used by the theorist not of the underlying domain they are studying. Mathematical modeling of evolution falls into two broad categories: frequency-dependent and frequency-independent models. Frequency-dependent models almost never make the micro-macro distinction. Although you could argue that dynamic models in evolutionary game theory are micro, and static equilibrium concepts like ESS are macro, but I doubt theorists would endorse this view. As such, I will focus on the frequency-independent models.

For frequency-independent models, they key concept is the fitness landscape -- a way to map each genotype to a fitness. If the model tracks a population (a distribution over vertices in the fitness graph) on a static fitness landscape, then it would typically be just called an evolutionary model (the word microevolutionary is seldom used explicitly in this field). However, if the authors assume that mutations are extremely rare and thus any mutant goes to fixation before a new one arises then they can use Gillespie (1983, 1984) to replace the population by a single "typical individual" occupying one vertex of the fitness graph. At this point, the model becomes macroevolutionary and the underlying rule for calculating fixation probabilities would be the microevolutionary component. This approach is often also coupled with an alternation of change in fitness landscape followed by mutations and a selective sweep. Fundamentally, though, macroevolutionary models are just convenient (or tractable) approximations to a real underlying evolutionary dynamics. This should never be forgotten.

Strange example bridging the gaps

Finally, it is important to stress that the macro- and micro-evolutionary paradigms are not necessarily exclusive and do not have to correspond to a difference in timescales! This is best done with an example of a respected theoretical study that mixes everything together. Kauffman & Weinberger (1989) used their newly developed NK model or rugged fitness landscapes to study maturation of the immune response (Tonegawa, 1983). The developed a macroevolutionary mathematical model because they used Gillespie's trick to replace a population by a typical individual by abstracting away from the underlying microevolutionary calculation of fixation probabilities. However, their model was studying evolutionary dynamics within the human immune system (so timescales of days to weeks) and was tuned by parameters gathered by empirical microevolutionary studies that tracked individual nucleotide changes (Crews et al., 1981; Tonegawa, 1983; Clark et al., 1985). Lastly, the study results can be used to inform a question typical of verbal macroevolutionary theory: Are there any examples of sudden leaps in evolution?.

As such, the above study used a formal macroevolutionary model, informed by empirical microevolutionary work, to help us understand a question typical of verbal macroevolution while looking at a physical process that operated on the incredibly short timescale of days to weeks. No wonder people are so confused by the micro-macro "divide"!


References

Clark, S.H., Huppi, K., Ruezinsky, D., Staudt, L., Gerhard, W., & Weigert, M. (1985). Inter- and intraclonal diversity in the antibody response to influenza hemagglutin. J. Exp. Med. 161, 687.

Crews, S., Griffin, J., Huang, H., Calame, K., & Hood, L. (1981). A single V gene segment encodes the immune response to phosphorylcholine: somatic mutation is correlated with the class of the antibody. Cell 25, 59.

Gillespie, J.H. (1983). A simple stochastic gene substitution model. Theor. Pop. Biol. 23, 202.

Gillespie, J.H. (1984). Molecular evolution over the mutational landscape. Evolution 38, 1116.

Kauffman, S. and Weinberger, E. (1989) The NK Model of rugged fitness landscapes and its application to the maturation of the immune response. Journal of Theoretical Biology, 141(2): 211-245

Tonegawa, S. (1983). Somatic generation of antibody diversity. Nature 302, 575.


Basic Definitions of Macroevolution and Microevolution

Because the distinction between macroevolution and microevolution is fairly minor, you won't find the terms defined and separated in every science book — and not even in every biology text. You don't have to look too hard and too far to find the definitions, though, and it's important to note that macroevolution and microevolution are defined fairly consistently across many different types of scientific resources.

Collected here are definitions from three different types of books: basic biology text books like you would find in high school or college biology classes, introductory books on evolution that are intended for general audiences outside of school settings, and basic reference works (dictionaries, encyclopedias) on either science generally or some facet of biology specifically.


Macroevolution vs. Microevolution

Evolutionists blur the important distinction between micro and macroevolution. They work hard to make it seem like the two types of evolution are a continuous process, when really they are not. It is important for creationists to clearly understand and communicate this distinction. The key lies in understanding these processes at the molecular genetic (genotypic) level, as well as at the higher (phenotypic) level of tissues and organs. When we do, we can see clearly why microevolution happens all the time, whereas the kind of macroevolution theorized by Darwin never happened and never could. (In fact, some creationists are recommending that we try to get away from using terms like micro and macroevolution, and use terms like “variation” versus “evolution”.)

Microevolution is the occurrence of small inherited changes in a population. The classic example is Darwin’s finches, which show variations in size and shape over successive generations depending on the nature of their food supply. Many other similar examples could be readily cited, like the breeding of dogs or types of wheat. In Darwin’s day, the true nature of genes and heredity wasn’t known, so it was easy for him to suppose that little inherited changes could add up to big ones (like reptile to bird). However, the discovery of genes and how they work has shown that this is not so. Genes can impart great variety by combining in different ways, but genetic change cannot be pushed beyond a certain point. From generic dogs, we can breed big dogs or little ones, but we can’t turn a dog into an alligator. The important thing to remember about microevolution is that it always involves recombination or loss of existing genes. It never creates totally new genes from scratch. Microevolution makes variations within already existing kinds of creatures, not wholly new kinds. Creationists have no problem with microevolution.

Macroevolution, on the other hand, would require really big structural (phenotypic) changes in organisms. Genetically, it would require the creation of massive new arrays of information-packed genes from nothing but molecular gibberish. For example, the alleged evolution of the first cell calls for emergence of at least 300 highly complex, working genes from nothing but random, simple chemicals like methane and ammonia. Not even a small sequence of genetic code has ever been produced in this way, let alone 300 complex, interwoven genes working precisely together. Similarly, the theorized transitions from microbes to invertebrates, fish, reptiles, etc., call for added vast amounts of totally new genetic information at each stage. No process of genetic creation like this has ever been observed. Natural selection is powerless to create completely new genes from random chemicals.

To illustrate this idea, use a deck of playing cards to represent the gene pool of a created kind. The individual cards represent the genes. A standard 52-card deck of four suits can be shuffled and dealt into different sublets (hands) of great variety, just as genes are shuffled and recombined to create variations within kinds.

To show how microevolution works, deal out 5-10 cards to each “player” and have them select cards in their hands according to number, color, and suit. Then, unwanted cards can be returned to the remaining deck, reshuffled, and re-dealt. When the process is repeated a few times, the desired cards in the hand are concentrated. This is similar to the gene selection by which different variations within a kind are produced (like the Galapagos finches, or dog breeds).

The point is that any process of card selection cannot explain the origin of the deck (or creature) itself. Plus, it’s important to note that card selection causes other unselected cards to be lost from a hand. In the genetic world every species has a limited number of genes and chromosomes. When natural selection occurs, this means loss of information not gain.

So, let’s keep on calling attention to the vital difference between the two types of evolution – macro and micro. One postulates big changes the other deals only in small changes. One has never been observed the other has been observed many times. One requires creation of new genetic information the other is only a recombination or loss of already genetic information. Most importantly, one denies the Creator, while the other shows the infinite creative genius behind the wonderful variety that we see in life.

Originally published in the November/December 2005 issue of Think & Believe newsletter .

Please call our office or email us at [email protected] for additional resources on these subjects.


Macro- vs. Micro-evolution

I will save you a lot of reading: All you need to know is that "macroevolution" when used in the context of the Senapathy theory means long-term, non-observable changes, including natural selection and descent with modification. This is the extension of Darwin's theory that Dr. Senapathy says is wrong. Macroevolution does NOT include short-term, observable changes, including artificial selection and environmental adaptation (that's "microevolution" ) --there is no dispute in the new theory that those mechanisms work.

If you are a masochist, read on.

From Patrick O'Neil: There is NO distinction between MICROevolution and MACROevolution. The processes are identical - the only difference is one of accumulated extent and/or the nature of the genetic element, be it a gene, chromosome segment, whatever. A point mutation at one locus in one gene can have absolutely no effect on biochemistry and phenotype OR it can have drastic effects. A series of separate point mutations over time can act the same way. A transposition event can be innocuous or a major alteration. A recombination event of other types can be minor, major, or a fatal change. No difference between one and the other except in the deluded eyes of the creationists.

From Una Smith: Darwin observed large evolutionary change over geological time, and small to modest evolutionary change over ecological time (most dramatically in animals under intense selection by man). His brilliant idea was that the fundamental process underlying both was the same.

JM: His idea would be brilliant, I agree, if it was correct. The ideas that the Earth was flat and at the center of the universe were also considered simple and brilliant ideas in their time. The processes of macro- and micro-evolution are NOT the same. Dr. Senapathy at page 65: "Darwin had extrapolated the power of artificial selection in producing breeds to the power of natural selection in an extended geological time producing unique creatures with new genes and body structures. But neither artificial selection nor natural selection can ever extend beyond the confines of the closed permanent boundary of a distinct creature. And this was Darwin's mistake." That statement is surrounded by much discussion and supporting information.

Senapathy does not use the terms "micro" and "macro." You probably know the two as Darwin's special theory and general theory. Darwin assumed they worked the same way. In a search for "brilliance," you are ignoring much evidence of problems with the general theory. The process by which a moth's color changes is not the same process that caused flippers to "change" into feet.

Una: The problem is, indeed, to show precisely how the processes we observe to produce small changes to existing forms in ecological time can be scaled up to produce what seem to have been novel forms over geological time.

JM: That is not the problem ("to show how . process . can be scaled up") -- the problem is to understand how the small and large differences between organisms came about, and see if they are related. You then live with what you find out instead of trying "to show" that what you saw fits into a presupposed, single, simple theory. You are making the same mistake that Darwin did: making and assumption that two similar-appearing effects are caused by the same thing.

Una: Senapathy tries to solve the problem by sweeping vast amounts of messy evidence under his rug, and then trying to distract everyone by pointing out how neat and small his rug is. Sorry, but parsimony works by counting all the pieces of evidence not explained by a theory, not by hiding the evidence and counting the parts of the theory instead.

JM: You are ignoring "all the pieces," too. Senapathy's book is lengthy, and only a small fraction of his theory has been presented in detail here. You need to read his book before you can say he has ignored anything. Isn't that fair? The actual presentation of his theory takes a relatively small space in the middle of his book -- all the rest is showing how the observed facts and the new theory fit together and where those facts fail to explain the general theory. Nothing is being ignored.

From Patrick O'Neil: Oh for. For the second time. There is no difference between MICROevolution and MACROevolution. The underlying process IS IDENTICAL. It is merely predicated upon the particular mutation type in a particular location within a particular gene. The mutation can be a point mutation, a transposition event leading to a fusion, a gene duplication (which REALLY allows new, novel functions to develop without harming the host in many cases), and so forth. A point mutation may not do squat or it might so alter the resulting protein's conformation or function that it has drastic phenotypic effects. Same with ALL the other mutation types.

The ONLY thing required to initiate the formation of a new species of whatever is a minor change in an isolated population's mating biology: for animals that experience estrous, this can mean a VERY minor alteration in fertile cycles such that they can no longer mate with other related creatures. It can mean an alteration in egg receptors such that only a specific variant of sperm ligand can productively bind. There are ANY number of simple means by which a new species can come into being and once one does, it can go in a direction morphologically and behaviorally independent from its precursor species.

From Una Smith: (quoting JM) [Darwin's] idea would be brilliant, I agree, if it was correct."

Una: It is brilliant regardless of whether it is correct. And vast amounts of research over the past century have failed to disprove it, hence it would appear to be correct.

JM: "The processes of macro- and micro-evolution are NOT the same."

Una: This assertion contradicts a great deal of well-documented fact. Furthermore, Keith Robinson has shown that the evidence in favor of this assertion, as given by Senapathy and repeated by you, is based on serious errors of math.

JM: "Darwin assumed [microevolution and macroevolution] worked the same way."

Una: Not so. Darwin's Origin of Species is devoted to establishing the hypothesis that they work the same way, and giving evidence in support of this hypothesis.

From Roger Gary: I just picked up Michael Denton's Evolution: a Theory in Crisis. He also distinguishes Darwin's "special" from his "general" theory. I am only a lowly undergrad, but in 37 semester hours of paleontology, biology, and zoology I have never even heard such a distinction mentioned. Rather odd to run into it twice in two days. Has any non-creationist ever proposed such a distinction?

It seems to me that arguing that microevolution is qualitatively different from macroevolution is like arguing that no matter how many letters of the alphabet I add, change or delete, I could never transform On the Origin of Species by Means of Natural Selection, or the Preservation of Favored Races in the Struggle for Life (I love that title) into the King James Bible .

From Neil Foglia : [Does anyone worth listening to consider] macro-evolution to differ significantly from micro-evolution? Gould and Eldredge have argued that "macro-evolution is not micro-evolution writ large." Yet I do not recall any significant alternative view that they offer as to why this would be so.

They consider macro-evolution to be the area of evolutionary theory that is concerned with an actual speciation event that goes beyond mere>micro-evolutionary changes. That is a more pronounced change than amino acid substitutions or gene mutations. Just how big of a change they are looking for I don't know, but suspect that it would be along the lines of drastic morophological adjustments.

By recent exposure to some of the latest thinking on punctuated equilibria, I am leaning to the view that what they have proposed does not differ that significantly from the views already contained within the modern synthesis. P.E. appears to mandate geographic isolation in order for speciation to occur. Mayr has held to similar views and in fact had been criticized for making geographic isolation a requirement of speciation. About the only difference that I can see right now, is that P.E. also requires that this isolation be in conjunction with small population numbers. In other words, geographic isolation alone, when applied to a wide spread and numerous population, may not result in drastic evolutionary change.

The marine record offers many examples when this appears to be the case. If the populations of a species is numerous, then the degree of separation is on the micro-evolutionary scale. From this one might infer that when the census number of the isolated populations are low, then the changes may become more pronounced. Why this is so is not clear to me, so what follows is mere speculation on my part.

A smaller population isolated from a larger group would have less genetic diversity, but shouldn't they also be more genetically conservative? Perhaps their genotypes are not as coherent do to the fact that rare mutations can spread more quickly in a smaller population. If this is the case, then by enabling micro-mutations to take hold more quickly in smaller populations macro-evolution becomes possible. I think!

From Phil Nicholls: In Evolution and Entropy: Toward A Unified Theory of Biology by DR Brooks and EO Wiley, microevolution and macroevolution are distinguished from each other on the basis of reversibility. They make an analogy between macroscopic and microscopic processes in thermodynamics. Thus in microevolution there is no "arrow of time" to the extent that the process can be run backward. Hence in the classic example of Industrial melanism when the pollution of the industrial revolution was reduced and trees resume their natural coloration the frequency of mottled to black moths changed again.

Macroevolution is identified with speciation. Once speciation has occurred the gene pools are permanently separated. Selection and adaptation after speciation has occurred will increase genetic divergence which in turn will increase the amount of morphological divergence. Hence morphological divergence is a result of speciation but not the cause of speciation.

From Shane McKee: Is there any qualitative difference between "macro" and "micro"? I don't think this has been demonstrated at all. All the differences seen at the "macro" scale turn out to be the same differences, qualitatively, as those seen at the "micro" scale. Nobody uses those archaic terms, "micro" and "macro" any more, do they? Your usage of the terms seems to stem from the levels either side of the species barrier, which is a shaky one at best to use for fundamental distinctions.

Actually, there's a hell of a lot more controversy about gravity [than evolution]. The controversy is in how it works. We know a lot of the mechanisms of evolution, from the bottom up, but know practically nothing of the underlying mechanisms of gravity.

Darwin's theory was that change was produced in populations due to repeated selection of favorable variations. Genetics and molecular biology have shown how this works. There is no controversy that natural selection works. Random genetic drift also plays a part. No big controversy here.

It's worth trying to understand the theory (i.e. the rules and principles) of evolution, and also to learn some molecular biology. Then you'll see that at the most basic level, there's not a lot of difference between a human and a cat.

From Shane McKee: Dr. Senapathy seems to fail to understand what the genetic code actually does in the development of an organism. The DNA is not a blueprint for an organism, of which bits can be lifted and laid willy-nilly, but, to use Richard Dawkins' analogy, more like a recipe. The finished product is due to the complex unfolding of the process, which is damned difficult to predict in advance.

JM: I don't know why you say this, other than perhaps because I have not described Dr. Senapathy's theory in enough detail for you to understand it. Senapathy's book is full of discussions about developmental genetic pathways and references to undisputed genetic theory having to do with how genes control the development of an organism. However, if you can be more specific with a question, I'll try to respond.

Shane: There is no specific genetic blueprint for the forelimb of a coelophysis, in the sense that you could just change that one section and get, say, a bat-wing. It's a complex emergent phenomenon. This is in direct contradiction with the notion of re-use.

JM: Again, I don't understand why you think this about reuse. Reused genes form only part of new organism -- there is also a random amount of new DNA. The reused genes are random, too.

Senapathy can no more demonstrate the formation of life in the lab than you can objectively demonstrate macro-evolution.

Shane: Do you mean speciation? That has been demonstrated objectively in fruitflies, and even Darwin himself showed some pretty impressive results with pigeons.

JM: Senapathy has no problem with that -- those things are part of what I term "micro" (and maybe for the last time :-). Artificial selection and many adaptations do occur. These do not involve new body parts or new genes (see below).

Shane: By "macro-evolution," what do you mean? Species level? Genus level? Phylum?

JM: Yes, I agree that the "macro" term is causing problems. Senapathy draws the line this way: body parts and new genes. If two organisms have different body parts or a totally new gene, then they came about independently. There is one exception, and that is if the developmental genetic pathway for a body part has been turned on or off (through changes in protein levels, for example) in some later descendant. But that does not involve a significant change in the genome, just a change in expression or the level of expression.

By the way, "micro" and "macro" are not terms that Senapathy uses anywhere in his book -- I used them because they made sense to me, but I now regret doing so because of the confusion.

Shane: Any organism can be thought of as occupying one particular point in multibillion-dimensional genetic space. Evolution supposes a branching path to any location thus-far attained. Dr. S's notion presupposes the trial of just about every point de novo . Genetic data clearly favors the former, and to my mind actually falsifies the latter, or at least makes it very unlikely.

JM: You are not leaving room for the commonalities that Senapathy predicts. Reuse of parts of successful genomes will generate similarities, and they will be tree-like.


Macroevolution vs. microevolution - Biology

Creationists generally seem to have no problem accepting Microevolution or "variation with kinds" as they call it, but they outright reject Macroevolution because as they not only argue there's no evidence for it but also that it just can't happen.

The problem is that Creationists already accept that Speciation happens, and since Macroevolution generally starts with speciation [2], this means that Creationists already accept Macroevolution. To get around this contradiction in logic, Creationists attempt to redefine the word Macroevolution to mean biological change from one "Kind" of organism to another "Kind" of organism [1]. By doing so, Creationists can easily dismiss any and all evidence for Macroevolution on the grounds that it doesn't fit their undefined criteria for one "Kind" changing into another "Kind".

Given the types of Evolution we've directly observed, as pointed out by Darwinzdf42 [3], which includes things such as the Evolution of Multicellularity, Endosymbiosis, Viviparity, etc. or the diversity we see amongst Plants that are compatible for Crossing and or Grafting [4,5], which is usually incontrovertible evidence of their common heritage. or just the extreme levels of biodiversity Creationists accept within Plant and Animal "Kinds" [6,7]. I personally see no difference in what Biologists would normally describe as Macroevolution compared to what Creationists accept as variation within "Kinds".

As a means of clarifying what the Creationist's criteria might be for what they think should count as Macroevolution, I have a few questions I'd like to ask them


Microevolution and Macroevolution: Macroevolution

Whereas microevolution explains diversification on an individual level over relatively short periods of time, macroevolution defines changes in large populations that often entail catastrophic environmental changes.

Geological Evidence

The fossil record establishes the ancestral lineage of both plants and animals and identifies periods of punctuated equilibrium in both. Rock strata can be used to date fossils because the organisms from which the fossils were derived died and were eventually buried in the material from which the rock was made. This allows a relative dating of the fossils by assigning their age in comparison with other rock strata. Except in the case of major Earth events, such as mountain building and erosion, the youngest rock strata and the fossils they contain are closest to the earth's surface and become older the deeper they are found in the crust. Also, rock strata in neighboring areas can be reconciled with each other if they are composed of similar rock or mineral type.

The evolutionary history for an area is arrayed in rock layers that jigsaw together to trace the macroevolution or major events of the history of life on Earth. As paleontologists discover fossils in a rock layer, they can make assumptions based on present-day life-forms about the environmental conditions that existed at that time. For instance, the discovery of a fern fossil would indicate a warm or temperate climate, adequate precipitation, and perhaps shade, all of which are conditions that support the growth of modern-day ferns. It may also provide clues that link with other fossil evidence to shed light on the animal life present at that time. For instance, an environment that supports ferns would also likely support herbivores like snails or an assortment of grazing animals that might feed on ferns.

Bionote

Carbon-14 analysis is effective up to 50,000 years, after which other radioactive isotopes, such as potassium-40 and uranium-238, are used because they have a much longer half-life.

Radiometric Data Analysis

Additional fossil evidence is collected using radiometric data analysis, which is a more approximate dating of once-living organisms by comparing the ratio of radioactive isotopes in their remains to that found in the atmosphere. Radiometric dating compares the ratio of the normal carbon-12 atom to the unstable, radioactive carbon-14 isotope. While alive, the ratio of carbon-12 to carbon-14 atoms in any living organism is nearly equal to their ratio in the atmosphere. Upon death, the carbon-14 is no longer added to the organism, and the existing amount begins to decay at a constant and known rate to a more stable isotope like nitrogen-14. The decay rate for all radioactive isotopes is called their half-life, which means that one-half of their mass will be converted, or decayed, into the more stable form in a known amount of time. So if you can determine the ratio in the sample and compare it to the atmosphere and then multiply by the known decay time, or half-life, you can establish the age. The half-life for carbon-14 is 5,600 years, meaning that one half of the beginning amount will decay to nitrogen-14 in 5,600 years. Radiometric analysis gives an actual age of the specimen and, when combined with rock strata data, can yield a more accurate time and location placement.

Geologic Time Scale

Macroevolution is often displayed on a geologic time scale, which highlights major evolutionary events in a comparative time scale. The smallest units of time on the geologic time scale are called epochs and measure in the millions of years, such as the Pleistocene epoch approximately two million years ago that included the Ice Age and the appearance of the first human fossils. Chronologically, epochs are clumped together into larger units called periods, such as Quatenary, which are combined to make eras, such as Cenozoic, which are the largest unit of macroevolution measure. The following table includes examples of macroevolution, from the oldest to the most recent.

Geologic Time Scale Example
EraPeriodEpochEvent
Precambrian??Oldest prokaryote fossils.
PaleozoicOrdovician?Origin of plants.
Silurian?Land colonization by plantsand arthropods.
MesozoicJurassic?Dinosaurs roam.
Cretaceous?Dinosaurs are extinct flowering plants emerge.
CenozoicTertiaryPaleoceneRadiation of mammals and birds.
QuatenaryPleistoceneHumans appear.

Bioterms

A phylogenetic tree is like a family tree or pedigree. It shows the ancestral relationships and genealogy for an organism.

Phylogeny

Combined radiometric and rock-strata data analysis demonstrates evolutionary pathways for many plant and animal species. One of the most studied is the evolution of the modern horse, whose phylogenetic tree begins with a small, doglike creature and branches many times before reaching today's horse.

Backmapping the phylogenetic tree to establish evolutionary links between fossils establishes the science of systematics?the organized scheme of classifying all living things into their phylogenetic tree.


Dinosaurs on Noah's Ark

Students are often taught about some observable change in a population of animals, and told it’s an example of evolution. An example would be moths changing color based on the color of the trees they are sheltering on. The idea is that moths which are closer to the color of the tree trunk are less likely to be eaten by birds, so they are more likely to be the parents of the next moth generation. The next generation has more moths that are this safer color, because of genetics, and then soon most or all of the population has virtually changed color.

This is not the same as evolution.

The moth example shows moths adapting to their environment. The genetic information for a full range of moth colors already exists in the moth’s genes. The moths don’t turn purple, they just shift to a shade that is within the range of colors already specified by the moth DNA.

Evolution, the way the theory explains it, is a different animal. Evolution calls for new genetic material to be introduced. A fish is born with legs, where all previous fish didn’t have DNA for legs, for example. This is not something that has been observed, either within living populations or in the fossil record.

We see examples of natural selection, which is a better term than micro-evolution, all the time, and it doesn’t contradict the Bible. The Bible says God created plants and animals “according to their kinds.” (Genesis 1:11, 21, and 24). No one knows for sure what “kinds” are, exactly. Science classifies living things according to groups: the largest groups are kingdoms, such as the plant and animal kingdoms then there are phyla, classes, orders, families, genera and species. But these are artificial classifications, devised by man. Are “kinds” the same as “species” or not? We don’t really know.

In high school biology, I learned that species was defined as organisms that had the same characteristics and could produce fertile offspring. An example, to clarify, was given: a horse and a donkey can apparently have a baby, but the offspring won’t be fertile, so it’s not a new species. Dogs are all one species, because different breeds can still, well, breed.

But, again, these are artificial distinctions made by man. Where do you draw the line between two populations of moths who look the same but can’t interbreed because one lives in Europe and the other lives in America? They are isolated by geography, but they could interbreed if brought together. These are the kinds of questions biologists face, but God already knows the answer. He created the various kinds to reproduce after their kinds. That doesn’t mean all the grandbabies will be identical, but it does mean that an elephant momma won’t give birth to a baby zebra. And it does mean that a blond woman can give birth to a dark-haired child. The variation will be within the genetic differences for that kind. The baby will be the same kind as the momma. No new kind will arrive that has characteristics that are not in the genes of the parents.

This is the kind of distinction we need to explain to our children, so when someone teaches them that moths changing color is an example of evolution, they understand why it’s not true.


Sympatric Speciation

Sympatric speciation is the opposite of allopatric speciation because organisms, predominately plants, often create new species without the requisite geographic isolation. Plant-seed dispersal mechanisms often prohibit reproductive isolation, leaving sympatric speciation as the only major evolutionary cause agent for plants. Typically, a mutation occurs that prevents the offspring from successfully mating with a parent, but still allows viable reproduction with other individuals who inherited the same mutation. The most common mechanism is the chromosomal mutation that occurs because of a meiotic failure during gamete formation, when the chromosomes divide mitotically instead. When this happens, the duplicated chromosomes do not segregate and migrate into separate sex cells. Instead, they remain duplicated in the same sex cell, creating an overload of genes in certain gametes, which then become diploid, and deficient in others. It is possible then for the diploid gametes to unite with other diploid gametes to produce a polyploid individual, which contains more than the normal diploid complement of chromosomes. In plants, this occurs most frequently because of self-fertilization. The polyploid offspring can no longer successfully interbreed with the parent or any other similar-species organism that did not inherit the extra set of genes. Sympatric speciation is the reproductive isolation created by genetic abnormalities not as a result of geographic isolation. Although not widespread among animals, sympatric speciation has been significant in plant variation. Hugo de Vries, a Dutch botanist, is credited with identifying polyploidy as an agent of sympatric speciation. Through self-pollination, he created a large flowering polyploid evening primrose with 28 chromosomes instead of the normal diploid number of 14 chromosomes.


The Institute for Creation Research

There is much misinformation about these two words, and yet, understanding them is perhaps the crucial prerequisite for understanding the creation/evolution issue.

Macroevolution refers to major evolutionary changes over time, the origin of new types of organisms from previously existing, but different, ancestral types. Examples of this would be fish descending from an invertebrate animal, or whales descending from a land mammal. The evolutionary concept demands these bizarre changes.

Microevolution refers to varieties within a given type. Change happens within a group, but the descendant is clearly of the same type as the ancestor. This might better be called variation, or adaptation, but the changes are "horizontal" in effect, not "vertical." Such changes might be accomplished by "natural selection," in which a trait within the present variety is selected as the best for a given set of conditions, or accomplished by "artificial selection," such as when dog breeders produce a new breed of dog.

The small or microevolutionary changes occur by recombining existing genetic material within the group. As Gregor Mendel observed with his breeding studies on peas in the mid 1800's, there are natural limits to genetic change. A population of organisms can vary only so much. What causes macroevolutionary change?

Genetic mutations produce new genetic material, but do these lead to macroevolution? No truly useful mutations have ever been observed. The one most cited is the disease sickle-cell anemia, which provides an enhanced resistance to malaria. How could the occasionally deadly disease of SSA ever produce big-scale change?

Evolutionists assume that the small, horizontal microevolutionary changes (which are observed) lead to large, vertical macroevolutionary changes (which are never observed). This philosophical leap of faith lies at the eve of evolution thinking.

A review of any biology textbook will include a discussion of microevolutionary changes. This list will include the variety of beak shape among the finches of the Galapagos Islands, Darwin's favorite example. Always mentioned is the peppered moth in England, a population of moths whose dominant color shifted during the Industrial Revolution, when soot covered the trees. Insect populations become resistant to DDT, and germs become resistant to antibiotics. While in each case, observed change was limited to microevolution, the inference is that these minor changes can be extrapolated over many generations to macroevolution.

In 1980 about 150 of the world's leading evolutionary theorists gathered at the University of Chicago for a conference entitled "Macroevolution." Their task: "to consider the mechanisms that underlie the origin of species" (Lewin, Science vol. 210, pp. 883-887). "The central question of the Chicago conference was whether the mechanisms underlying microevolution can be extrapolated to explain the phenomena of macroevolution . . . the answer can be given as a clear, No."

Thus the scientific observations support the creation tenet that each basic type is separate and distinct from all others, and that while variation is inevitable, macroevolution does not and did not happen.