Yes - and it's obvious.
Here's an essay I wrote about the theories of evolution, it might be helpful:
Evolution is actually a combination of theories, much to the surprise of the creationists I often encounter. Typically when I encounter a creationist their idea of the multiple theories of evolution involve a difference between microevolution and macroevolution.
This is, of course, nonsense; macro-evolution is just a description of evolution above the species level. It does not actually act on separate principles from microevolution.
I will explain as best I can, using cites from actual experts in the field.
Now then, I made the allegation that the theory of evolution was actually comprised of several theories...so without further ado:
According to Ernst Mayr (who died recently) the five principle theories that comprise the theory of evolution are:
1. The nonconstancy of species (the basic theory of evolution).
2. The descent of all organisms from common ancestors (branching evolution).
3. The gradualness of evolution (no saltations, no discontinuities).
4. The multiplication of species (the origin of diversity).
5. Natural selection. [1]
So those are the five theories...what do they mean?
1. The nonconstancy of species: What this basically means is that every individual within a species is genetically different. Every individual's DNA has unique variations (not to the point that every individual constitutes a new species though). These variations usually express themselves in the phenotype.
To put this in a simpler fashion; no two individuals in a species are alike.
2. The descent of all organisms from common ancestors: All this means is that we came from our parents, who came from their parents. To put it in more general terms, it also means that we all came from one ancestor. Although if I recall correctly Darwin was open to the idea that there could have been a few original ancestors. In any event, one way to test hypothesis is to look at our genetics and to see if we share a genetic history with other organisms. After all, DNA is made up of four nucleotide bases-Tyamine, Cytocine, Adenine, and Guanine- and there is absolutely no reason that the DNA of one species should be related to that of another species unless at some point both species descended from a common ancestor.
3. The gradualness of evolution: Evolution is a gradual process, in that it happens slowly and over a considerable period of time. It's often at this point in the theory that creationists have the most difficulty. This is because they often confuse the 'saltation' with the process of evolutionary change involved in macroevolution.
Before we go any further I will define a few terms relevant to this part:
Saltation: This was a belief prior to the modern synthesis in the 1940's that scientists attributed to speciation. It was the belief that fully formed organs was responsible for speciation, and it's often also called 'macromutation'-which probably helps the confusion. In the words of Tim Berra, in his book "Evolution and the Myths of Creationism", clarifies the distinction:
No knowledgeable biologists today, and that includes the punctuated equilibrium enthusiasts, advocate single-generation macromutational jumps (mutations with large effects). Amphibians, for example, did not arise from the lobe-finned fishes in a single-generation leap (saltation), but by seeing the muscular fins and lung of the aquatic ancestor gradually refined for terrestrial life. Macromutations do occur, but they are usually harmful (the recipients seldom produce offspring) and therefore relatively unimportant in evolution.[2]
Macro-evolution: This is the change of a species above the species level. It does not actually work on a different process, separate from those that work for microevolution.
Micro-evolution: This is a change within a species.
The process for both microevolutionary change and macroevolutionary change is the same; it's based off the change in the alleles of a gene pool. With macroevolution, the gradual accumulation of these changes combined with genetic isolation (for example, the founder effect) can lead to speciation (which is just another word for a species branching into two species).
John Wilkins explains further:
There is no difference between micro- and macroevolution except that genes between species usually diverge, while genes within species usually combine. The same processes that cause within-species evolution are responsible for above-species evolution, except that the processes that cause speciation include things that cannot happen to lesser groups, such as the evolution of different sexual apparatus (because, by definition, once organisms cannot interbreed, they are different species).
The idea that the origin of higher taxa, such as genera (canines versus felines, for example), requires something special is based on the misunderstanding of the way in which new phyla (lineages) arise. The two species that are the origin of canines and felines probably differed very little from their common ancestral species and each other. But once they were reproductively isolated from each other, they evolved more and more differences that they shared but the other lineages didn't. This is true of all lineages back to the first eukaryotic (nuclear) cell. Even the changes in the Cambrian explosion are of this kind, although some (eg, Gould 1989) think that the genomes (gene structures) of these early animals were not as tightly regulated as modern animals, and therefore had more freedom to change. [3]
Gradualism: Gradualism is how the mechanisms of evolution work, populations change via the accumulation of slight modification over extended periods of time. The evolution of a species occurs slowly.
Tim Berra explains:
Most biologists operate on the Darwinian notion that a new species emerges from the old through the gradual accumulation of differences over long periods of time, typically in a population of one species that has become geographically separated from others of the same species. This view of evolution, the dominant one for a century and still today, is called gradualism. [4]
(Bolding his)
Punctuated Equilibrium: This is another view, similar to gradualism (it works off of the same microevolutionary principles), but the difference is the rate of evolutionary change and when it occurs. This is a point that creationists often confuse. The creationist view of this phenomenon is that punctuated equilibrium equates to macromutation-but this is incorrect. Stephen Gould and Niles Eldridge postulated that, for the most part, species remained relatively consistence after they speciate, they stayed in stasis. It is only when certain elements are introduced or when a population becomes geographically isolated that rapid speciation occurs, the new species diverge the most from their parent species during this time, followed by stasis. It should be noted, by rapid, Gould and Eldridge meant over millions of years.
Here's a picture from the Sixth Edition of "Biology"
To further elucidate punctuated equilibrium, I turn to Campbell and Reece, who write:
Advocates of the model called punctuated equilibrium incorporate ideas about the tempo of speciation in their explanations of what we see in the fossil record. According to this model, species diverge in spurts of relatively rapid change, instead of slowly and gradually. in other words, species undergo most of their morphological modifications as they first bud from parent species and then change little, even as they give rise to additional species. The term punctuated equilibrium is derived from the idea of long periods of stasis (equilibrium) punctuated by episodes of speciation.
How can speciation in a few thousand generations, which may require several thousand years, be called an abrupt episode? The fossil record indicates that successful species last for a few million years, on average. Suppose that a particular species survives for 5 million years, but most of its morphological changes occurred during the first 50,000 years of its existence. In this case, the evolution of the species-defining characteristics was compressed into just 1 f the lifetime of the species. On the time scale that can generally be determined in fossil strata, the species will appear suddenly in rocks of a certain age and then linger with little or no change before becoming extinct. During its formative millennia, the species may have accumulated its modifications gradually, but relative to the overall history of the species, its inception was abrupt.[6]
Mutation: A mutation is a change in the DNA of an organism, via an error in copying the genetic information. It is typically asserted by creationists that there are no beneficial mutations and that mutations can not lead to new information. Both of these assertions are false.
According to this website, there are three main types of mutations:
Basic types of mutations are:
Point mutations are usually caused by chemicals or malfunction of DNA replication and exchange a single nucleotide for another. Most common is the transition that exchanges a purine for a purine or a pyrimidine for a pyrimidine (A ¡ê G, C ¡ê T). A transition can be caused by nitrous acid, base mispairing, or mutagenic base analogs such as 5-bromo-2-deoxyuridine (BrdU). Less common is a transversion, which exchanges a purine for a pyrimidine or a pyrimidine for a purine (C/T ¡ê A/G). A point mutation can be reversed by another point mutation, in which the nucleotide is changed back to its original state (true reversion) or by second-site reversion (a complementary mutation elsewhere that results in regained gene functionality). There are three kinds of point mutations, depending upon what the erroneous codon codes for:
*silent mutations: codes for the same amino acid, so has no effect
*missense mutations: codes for a different amino acid
*nonsense mutations: codes for a stop, which can truncate the protein
Insertions add one or more extra nucleotides into the DNA. They are usually caused by transposable elements, or errors during replication of repeating elements (e.g. AT repeats). Most insertions in a gene can cause a shift in the reading frame (frameshift) or alter splicing of the mRNA, both of which can significantly alter the gene product. Insertions can be reverted by excision of the transposable element.
Deletions remove one or more nucleotides from the DNA. Like insertions, these mutations can alter the reading frame of the gene. They are irreversible. [7]
It should be noted that beneficial mutations have been observed several times. Additionally here's yet another example of information being added to the genes of E.Coli, taken from this website:
Both plasmid mediated and chromosomally determined resistances have been described. There are plasmid-mediated extended-spectrum b-lactamases (ESbs), which cause resistance to most penicillins, cephalosporins and aztreonam. In addition at least six chromosomally mediated b-lactamases have been distinguished in ampicillin-resistant E. coli by isoelectric focussing. Most ampicillin resistant strains of E. coli produce this b-lactamase as well as a plasmid-mediated enzyme. E. coli has a number of mechanisms to further develop antibiotic resistances, such as by increasing the number of gene copies encoding for the production of a b-lactamase, it can increase the level of b-lactamase leading to drug resistance. Alteration of the promoter or attenuator regions affecting gene transcription or changing the complex regulatory apparatus involved in inducible b-lactamase expression, the levels of these enzymes can similarly be increased. The basis for the resistance to clavulanate, despite the enzyme being clavulanate sensitive, is the production of high levels of enzyme due to a high copy number of the structural gene. Levels of resistance increase with rising enzyme levels. Both the b-lactam drug and the b-lactamase inhibitor of the drug/inhibitor combinations would probably be permeating through the same pathway. If the E. coli only produce low levels of b-lactamase then the inhibitor would inactivate the b-lactamase. If the E. coli strain is a high level producer of b-lactamase then the amount of inhibitor permeating into the cells would be insufficient to inactivate all the b-lactamase. Mutations causing decreases in permeability will also augment the resistance of E. coli. Clinical situations have yielded mutants of E. coli able to overproduce AmpC b-lactamase. These are resistant to inhibitor/b-lactam combinations, second and third generation cephalosporins and cephamycins. The enhanced expression of AmpC b-lactamase appears to arise by mutation of the ampD gene, whose product prevents the transcription of the structural ampC gene. This gives stable high-level production of b-lactamase. The b-lactam resistance observed among clinical E. coli isolates seems mainly to be mediated by TEM b-lactamase, with the observed varied spectrum of resistances being determined by a number of additional strain-dependent factors. The TEM-1 enzyme has been found in many E. coli isolates including commensal strains isolated from the faeces of healthy volunteers.[8]
What this rather dense paragraph is saying is that not only can the number of genes be increased (ie, increased 'information') but genes can be altered to create new types of information.
Now then, back to the five core theories.
4. The multiplication of species: This means that species will undergo speciation, or that daughter populations will split off from the parental population-forming a new species. A lot of the information concerning the rates of speciation and the causes were discussed in the definitions section.
5. Natural Selection: This is the primary idea that Darwin endowed us with. The idea of natural selection is that when new mutations or variation within the genome arise nature acts as a selective pressure to 'cull' the mutations /variations that promote a species not only surviving, but also reproducing.
Putting it another way, Carl Zimmer writes, regarding natural selection:
The fortunate few who got to reproduce themselves wouldn't be determined by pure luck. Some individuals would have traits that would make them better able to survive under certain conditions. They might grow to be big, they might have a particularly slender beak, they might grow thicker coats of fur. Whichever individuals were born with these traits would be more likely to have offspring than weaker members of their species. And because offspring tend to be like their parents, they would pass on those winning traits to their young.[9]
With that I bring a close to this brief introduction to the five theories that comprise what is commonly known as the modern theory of evolution.
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1. Ernst Mayr, What Evolution Is (Basic Books 2001). Pg. 86
2. Tim M. Berra, Evolution and the Myth of Creationism (Stanford University Press 1990). Pg. 47
3. John Wilkins, http://www.talkorigins.org/faqs/macroevolution.html (1997).
4. Tim M. Berra, Evolution and the Myth of Creationism (Stanford University Press 1990). Pg. 46
5. Campbell and Reece, Biology, Sixth Edition (Pearson Education, Inc. 2002) Figure 24.17, Pg. 476
6. Campbell and Reece, Biology, Sixth Edition (Pearson Education, Inc. 2002). Pg. 476
7. http://encyclopedia.laborlawtalk.com/Mutation
8. http://ecoli.bham.ac.uk/path/antir.html
9. Carl Zimmer, Evolution: The Triumph of an Idea, (WGBH Educational Foundation and Clear Blue Sky Productions 2001). Pg. 34-35