It is most commonly defined as “the evolution of higher taxa.” It is thought to provide the mechanism by which an original taxon (i.e. phylum or class) may morph enough to result in newly descendant phyla or classes. The development of new taxonomic groups requires new types of structures (morphology) and functions.
Macroevolution has been oversimplified as a theoretical process thought to produce relatively large (macro) evolutionary change within biological organisms. The term is used in contrast to minor (micro) changes. However, this is a poor way to describe any kind of evolution, which is based on small baby bite-sized gradual steps. In order for large change to occur, many successive steps are required. For example, the transition from a reptile to a mammal would require a long chain of intermediate steps; each minute transition being one tiny gradual degree of variation, one mutation at a time, gene by gene, one generation to the next.
The concept of macroevolution was introduced due to the absence of transitional forms between higher taxa (i.e. phyla, classes), which is in stark contrast to the expectations of Darwinian gradualism.
Microevolution: In contrast to macroevolution, microevolution is not a long chain evolutionary steps, but just one solitary step. This would most likely be a single mutation when a gene evolves causing a slight, even undetectable variation. If a gene mutates, then microevoluton as occurred. Evolution could be defined simply by a change of allele frequency from one generation to the next within a population. These kinds of subtle variations are commonplace, and is one reason why evolution is said to be an observable event.
Microevolution leads to visible variations in the phenotype, variations lead to adaptations, adaptations eventually lead to speciation. As a population continues to morph after successive variations, the phenotype will genetically drift apart to be so distinguished from other populations in the species that mating between the two population terminates. A speciation event happens when evolution has caused two different populations of a species to no longer mate.
Assuming common descent is a valid premise, logic would suggest that any speciation that takes place at higher taxa levels is an example of macroevolution. Macroevolution is the accumulation of microevolutionary differences. Observation of microevolution then is sufficient to demonstrate the plausibility of macroevolution. The evidence for macroevolution is a phylogenetic comparison.
Ever since the term macroevolution was first coined around the turn of the 20th century, its definition includes speciation. The reasoning for this is simple. Speciation typically requires numerous mutations and modification to happen before a population is so distinguished from other populations within the species that a new subspecies is generated. This being so, any evolution that occurs is always microevolution because change originates with the scrambling of genes and alleles at a molecular level. The term macroevolution emphasizes that a series of successive microevolutionary events transpired to visually result in a greater dramatic morphology. When macroevolution is discussed, it is implied that microevolution also occurred.
Common Descent requires speciation to occur. Speciation is a macroevolution event because most likely several instances of microevolution were required in order for the population to evolve into a new species. Therefore, macroevolution is commonplace because speciation is a very ordinary occurrence that is observed in nature.
Here’s where the discussion gets interesting. Speciation only occurs at the species taxon level. However, there are millions of organisms presently existing and accounted for that are unicellular or so primitive that they represent organisms in clades that are found in higher taxa. These species typically do not evolve in that they are essentially highly conserved. If evolution occurred at these higher taxa levels, then all such species within those clades would be extinct. The mere fact that many species still represent higher taxa is evidence of the fact that these more primitive life forms were conserved.
Speciation is observable, but not at all with these primitive life forms. This conflicts with evolutionary gradualism which is a required prediction of Darwin. If there is no gradualism, then Darwin’s theory fails. Speciation at these higher taxa levels, or macroevolution, is one of the most classic arguments ever presented by Creationists, and no Darwinist has ever been able to dispose of the challenge. This is what I am referring to when I use macroevolution as a compelling argument in support of ID theory.
We see speciation take place at the species level, which produces a subspecies. This is the lowest taxon. There are no lower taxa than subspecies. This is where speciation takes place, and it is observable. The higher you move up the clades, you go from complex organisms to primitive ones.
Species of Protista, schizomycophyta, myxomycophtya, eumycophyta, Lichenes, protozoa, Mesozoa, Euglenophyta, Pyrrophyta, Chrysophyta, Phaeophyta, Choanoflagellates, Sarcodina, Ciliophora, Mastigophora, Amoeba, Ctenophora, cnidaria, Myxozoa, Acoelomata, bacteria, are all examples of HIGH TAXA. Most of them are single-celled organisms. Species within these classifications do not evolve. They ADAPT, but they don’t evolve. Species within these classifications remain the same species. No speciation occurs at these higher taxa levels. If speciation were to occur at a higher taxon or clade, such as the ones listed here, this would be macroevolution.
Here’s a scientific problem to solve:
Necessary Condition: Show occurrence of speciation for any of the sufficient conditions
- Any species sample of Protista provided
- Any species sample of cyanophyta provided
- Any species sample of schizomycophyta provided
- Any species sample of myxomycophtya provided
- Any species sample of eumycophyta provided
- Any species sample of Lichenes provided
- Any species sample of protozoa provided
- Any species sample of Mesozoa provided
- Any species sample of Euglenophyta provided
- Any species sample of Pyrrophyta provided
- Any species sample of Chrysophyta provided
- Any species sample of Phaeophyta provided
- Any species sample of Rhodphyta provided
- Any species sample of Fungi provided
- Any species sample of Choanoflagellates provided
- Any species sample of Sarcodina provided
- Any species sample of Ciliophora provided
- Any species sample of Mastigophora provided
- Any species sample of Amoeba provided
- Any species sample of Ctenophora provided
- Any species sample of cnidaria provided
- Any species sample of Placozoa provided
- Any species sample of Myxozoa provided
- Any species sample of Acoelomata provided
In this list I just provided, there is no difference in organisms from the phyla taxon to the species taxon within these classifications because no evolution occurred. If you take a dog, cat, horse, human, or whatever, there is a vast difference from species, genus, family, order, and all the way on up each classification. But, in the list I just provided, there is very little change. Any species of organism on the list I provided looks just like it’s most primitive ancestor. There is no change in the list I provided from species, genus, family, order, class, phylum, to kingdom. In the list I just provided, there is no variation, no change, evolution did not take place like it did in other phyla.
There are obviously SPECIES within all these classifications such as Eukarya, Bikonta, Opisthokonta, Animalia, Protista, Protozoa, Porifera, Eumetazoa, Placozoa, Sarcodina, Ciliophora, Mastigophora, Amoeba, Ctenophora, Cridaria, Myxozoa, Bilateria, Acoelomata, Pseudocoelomata, Ceolomata, Protostomia, Deuterostomia, Ecdysozoa, Lophotrochozoa, etc. These represent PRIMITIVE phyla. Yes, we humans are all eukaryotes, but there are still species that are at the single cell primitive Eukarya phylum level. These are all examples. You can choose any phylum you want. Choose any species at these primitive levels you want. Some of these classifications listed here ARE actual species, but in each case these represent very primitive life forms. What you will find is that speciation does not occur here with these species, not even Eukarya, which supposedly evolved all the way to homo sapiens. You won’t find speciation at these higher taxa levels. That’s a problem.
The point that should be obvious upon reviewing the above graph is EVERY SINGLE MACROEVOLUTION OPPORTUNITY AVAILABLE FOR SPECIATION TO OCCUR, IT NEVER HAPPENS WITH HIGHER, MORE PRIMITIVE TAXA. THERE ARE NO EXCEPTIONS!!!!
So, here’s yet one more argument for design. If the natural Darwinian mechanisms of natural selection and mutations were the only factors required to achieve the diversity of life by common descent, then higher taxa should evolve just as readily as organisms found in a lower taxon. This isn’t the case. The higher the taxa, the more conserved life forms are. As frequent and ordinary of a standard as macroevolution is at lower taxa, macroevolution becomes nonexistent at higher taxa. For example, cases involving speciation occurring at a genus or family clade (an instance of macroevolution) are routine in nature. But, the probability that speciation will occur at higher taxer dramatically reduces to becoming essentially impossible when approaching the superphyla, kingdom, and domain levels. This fact is expressed in the above graph. It is a compelling argument for design.
The argument works with the domain eukarya even though this is the domain that exploded with complexity. Actually, I would accept any species from the super high taxa, in these classifications, but I am avoiding them to make the task easier. What I am trying to do is locate super primitive species wherever they can be found. What we will find is that there is very little variation between super primitive species with their genus, family, order, class, and phylum. The question is why?
All anyone has to do was look up just one species on that list I provided, show that speciation occurred within that classification, and – wallah – the macroevolution argument would be scientifically falsified. The observation here is that there are NO organisms that evolve at higher taxa, not one last one of them. It would be okay to see that many species do not evolve. That’s no problem. What is a problem is that there is not one example of a primitive species evolving. At least SOME primitive species should continue evolving, but NONE of them are. That’s the point.
Multicellular eukaryotic examples should be fine if we are up around a subphylum, phylum, superphylum level of primitivity. I would look at order, class, and family levels of complexity, too, as these are generally high enough taxa to prove the point. As eukaryotes become more complex toward genus and species, we are no longer witnessing macroevolution. Speciation of eukarya at the genus level of complexity or species is entirely microevolution because eukaryotes ended up being the most complex organisms on the planet.
Perhaps the most stunning example of this sort of speciation event in protists comes from the work of Kwang Jeon (Jeon and Jeon 2004). The research paper is here, http://jcs.biologists.org/content/117/4/535.full.pdf+html.
Basically, what is described here in this paper is we have a new strain of Amoeba generated from this example. For anyone trying to follow the story, it’s really quite simple. Basically, a vampire (x-bacteria) comes to a village of small-town residents (Amoeba strain D). The vampire (x-bacteria) goes to work, and as he does, people (individual amoebae of strain D) in the village begin dying.
However, a beautiful young girl (one of the individuals of population Amoeba strain D) is courted by the vampire (x-bacteria). She falls in love with the vampire (x-bacteria), but this relationship is just as lethal to her as it was the rest of the residents in the village. It basically kills her, or would have finished her off had she remained a mortal, but now because of her ongoing love affair with the vampire, she’s become a vampire herself (Amoeba strain xD).
Unfortunately, her friends, not realizing it’s too late save her, try to kill the vampire (antibiotic administered to population xD). They fail to kill the vampire, but that’s a good thing because they realize the further away the vampire (X-bacteria) is removed from her life, the sicker she becomes. They realize she now is a vampire herself and has a relationship with the vampire in that if somehow he is killed, then she will die, too. So, the only solution is that she (Amoeba strain xD) must be permanently removed from their community (parent amoeba strain D). Hence, a new strain of amoeba has speciated.
It still remains an uncommon event for amoebae to speciate, unlike bacteria that constantly form new strains. But, I can see that amoebae will speciate, and I would not be surprised to see other instances of amoebae speciating.
I do want to add a point that mitigates my mistake here. In this example, it was done entirely under a controlled laboratory environment. Adding the x-bacteria was an artificially done process. Then, a second artificial human intervention took place by administering the antibiotic. Finally, a third artificial human intervention took place by the lab technicians purposely and intentionally separating the cultures so that the xD population would not come in contact with the parent D strain. Had any of this occurred in nature, there would have been nothing other than an adaptation take place, the species would have remained the same, except for the adaption, and the weaker strain would have died off. Hence, the only way this macroevolution occurred is that it was ARTIFICIALLY INDUCED GENETIC DRIFT. So, I would hardly call this a fair example. But, the point is still made that the gene copying, folding, sequencing is active and volatile enough that I am convinced as a result of this experiment that it is possible amoebae could speciate in natural conditions, and that they are too low of taxa to be considered a candidate for macroevolution.
Just to clarify, the definition of macroevolution is explained in a variety of different ways depending on the authority source. I am fine to accept the common definition of macroevolution as noted in http://en.wikipedia.org/wiki/Macroevolution, or even the Talk Origins definition, http://www.talkorigins.org/faqs/macroevolution.html. The problem with any of these definitions is that they include speciation. Speciation is a scientific fact. Therefore, for a person to outright deny macroevolution occurs is to refuse to accept speciation, which hinges on a lack of credibility due to the fact that speciation is very much a given scientific observation that is only opposed by the most die hard of creationists.
Macroevolution refers to change occurring at or above the level of species, in contrast to microevolution, which refers to smaller evolutionary changes (typically described as changes in allele frequencies) within a species or population. [1. http://www.ncbi.nlm.nih.gov/pubmed/19212402; 2. Reznick DN, Ricklefs RE (February 2009). “Darwin’s bridge between microevolution and macroevolution”. Nature 457 (7231): 837–42; 3. http://www.nature.com/nature/journal/v457/n7231/full/nature07894.html; 4. http://en.wikipedia.org/wiki/Macroevolution].
As such, please note that it is important to distinguish that the above presented arguments deal with the SUBJECT of macroevolution in observing that evolution puts on the brakes and begins to become nonexistent at higher taxa levels. That’s the point of the “macroevolution argument.” The argument does not inherently in and of itself claim that speciaton does not occur, and neither does the above argument attack the common general definition of macroevolution. To put it yet even more simply and concisely, the conclusion is that all aspects of macroevolution does not occur except for speciation.
The macroevolution argument shows that evolution DOES NOT OCCUR WITH PRIMITIVE SPECIES AT HIGHER TAXA LEVELS!!! It doesn’t matter how you define macroevolution to include or exclude speciation. The point of the macroevolution argument has nothing to do with lower taxa, it has to be with very high taxa up around the domain, kingdom, phylum, class, order clades. Any species found at the same primitive level of these higher taxa DO NOT EVOLVE!!! It’s idiocy to do what you are doing and split hairs over whether macroevolution includes speciation or not. The ARGUMENT has nothing to do with lower taxa. If the term “macroevolution” just does you in, and paralyzes your ability to learn, then call the argument by another name, then. We can call it the “Supermacroevolution” argument, or the “Higher Taxon” argument, or the Primitive Population argument. The Nomenclature or semantics of how you label the name of the argument is irrelevant.
What needs to be done to clear the confusion is to abandon the term macroevolution, and adopt a new word that is defined exactly as macroevolution is defined, except that specation is not included. Whatever that might be called would be a better term than using the word, “macroevolution” in this argument. I would propose the phrase to be “Vertical Evolution.”
By abandoning the term macroevolution altogether, and discussing this subject with different nomenclature, such as using the expession, “Vertical Evolution,” might solve the semantics problem. When I refer to “Vertical Evolution,” I am no longer talking about speciation, but rather looking at the vertical movement up and down the phylogenetic tree of life, http://evolution.berkeley.edu/evosite/resources/images/haeckel_tree.gif.
When you look at a phylogenetic tree, you can see evolution occurring both vertically and horizontally. Let’s take a look at the horizontal evolution first.
Horizontal evolution is not just microevolution only, but it is all the variations and adaptations that take place within a species, genus, or family. So, in this case, the fact that the variations my include speciation or macroevolution are worthless to the discussion. What is important to note is that the variations are moving sideways, laterally. For example, there might be an infinite possible number of breeds of dogs, or hybrids of any particular life form. But a domestic dog is still just that.
Bacteria are a perfect example of the argument. Bacteria are one of the most primitive life forms you can find, and can be thought of either as a domain or .kingdom. You cannot find a much higher taxon than that. But, bacteria do not speciate. Strains evolve into new strains, but it’s all microevolution. Bacteria strains continuously adapt, even to the point where they break down nylon. But, there is never any increase in complexity. After billions of years of evolution, bacteria are no different today than what bacteria were billions of years ago. Because bacteria are at the domain, kingdom, and phylum level, speciation would certainly qualify as macroevolution by definition of macroevolution being speciation that occurs at higher taxa. But, bacteria do not speciate towards higher complexity, only adapt to different strains of the very same species.
Now, let’s take a look at VERTICAL evolution. To think of macroevolution yet another way, think of evolution occurring horizontally UP (vertically) the tree of life. At ground level (HIGH TAXA) you have roots and at the very top you have tender leaves (LOW TAXA). When you go up and down vertically, we are talking about increasing and decreasing complexity from primitive single-celled life forms to today’s modern complex species.
Now think of evolution in an horizontally along a clade or taxon. In this instance very little, if any, complexity is gained or lost. Variations occur, adaptations happen, even speciation takes place. But, there is no greater increase in information or complexity. Beaks might grow, shorten, fatten, or become thin. Exterior colors might change. Except for variations, the life form remains unchanged.
The macroevolution argument is about showing evidence of the vertical evolution taking place. Bacteria continuously adapt into new strains, but all the changes are horizontal. No matter how many years and generations of bacteria, bacteria today are essentially no different than what they were billions of years ago.
Some might take issue that it is bold for me to claim that bacteria haven’t changed in billions of years. For this reason I QUALIFY the assertion for purposes of clarity. When speaking of macroevolution, we ELIMINATE any form of microevolution! We are not talking about horizontal gene transfer, or variations within a species. Macroevolution includes speciation, but it INCLUDES MUCH MORE THAN THAT. Macroevolution GOES BEYOND SPECIATION all the way up to the domain taxa. Macroevolution includes speciation that initiates new genre of life forms responsible for the diversity of life.
Bacteria remain unicellular organisms with no nucleus, essentially unchanged. The only changes bacteria have incurred are all microevolutionary variations and adaptations. Bacteria give no evidence whatsoever of macroevolution because there is essentially no difference from the complex large genomes of modern bacteria with the more primitive forms of bacteria that would have flourished at the dawn of life. Until bacteria evolve into multicellular life forms, I will continue to assert that they have essentially remained unchanged in the context of macroevolution.
Paleontologist Steven M. Stanley states, “Despite the detailed study of the Pleistocene mammals of Europe, not a single valid example is known of phyletic (gradual) transition from one genus to another.” [Steven M. Stanley, Macroevolution: Patterns & Process (San Francisco: W. H. Freeman, 1979), 82.]
As an alternative—if genetic sequence differences among the major animal phyla are due to mutations steadily accumulated over long periods of time, it should be possible to use protein or DNA sequence differences in living species as a “molecular clock” to estimate how long ago they shared a common ancestor. However, Jonathan Wells showed how such analysis often produces bizarre results, such as grouping rabbits with primates instead of rodents, placing sea urchins among the chordates, and putting cows closer to whales than to horses [Jonathan Wells, Icons of Evolution, (Washington, D.C.: Regnery, 2002), 51.]