Definition of evolution
The definition of evolution has three aspects: hereditary changes, appearance of new species, and a theory explaining both of these. Currently there are several theories of evolution so a precise definition of evolution is impossible. It should be noted that most definitions of evolution make no claims as to the existence or non-existence of a god, though evolution is often associated with atheism.
Several different meanings have been and still are used in Biology and in the Origins debate, and this is itself part of the controversy over the general theory of evolution. Partisans on all sides of the dispute have accused other parties of tricking people by exploiting differences in the meaning of the word "evolution". Creationists charge that evolutionists often equivocate between different meanings, while evolutionists acknowledge that not clearly defining the term leads to confusion. The term evolution is most commonly used to describe Darwinian evolution by means of natural selection.
Definition of Evolution as Change Over Time
Douglas Futuyama wrote:
- The changes in populations that are considered evolutionary are those that are inheritable via the genetic material from one generation to the next.
Dr. Jonathan Sarfati states the following in relation to this definition of evolution:
|“||...many evolutionary propagandists are guilty of the deceitful practice of equivocation, that is, switching the meaning of a single word (evolution) part way through an argument. A common tactic, ‘bait-and-switch,’ is simply to produce examples of change over time, call this ‘evolution,’ then imply that the GTE [General Theory of Evolution] is thereby proven or even essential, and creation disproved. The PBS Evolution series and the Scientific American article are full of examples of this fallacy.||”|
The word evolution comes from Latin, meaning unrolling, and refers to any gradual change. But it has more precise definitions in popular and scientific use.
The broadest definition, change in the history of the universe, includes biological change, and non-biological change, such as galaxy formation. Theodosius Dobzhansky (1900-1975) said, "Evolution comprises all the stages of the development of the universe: the cosmic, biological, and human or cultural developments. Attempts to restrict the concept of evolution to biology are gratuitous."
Development of life
Kerkut defined the General Theory of Evolution as "the theory that all the living forms in the world have arisen from a single source which itself came from an inorganic form" As stated, this includes the origin of life (abiogenesis), but evolutionists today generally reject that evolution includes abiogenesis, as Natural selection can only operate once life has started.
Instead, it is defined as the development of life from some last universal common ancestor, from which all plants, animals, fungi, and other life on Earth are directly descended.
Webster's dictionary put it as, "...the development of a species, organism, or organ from its original or primitive state to its present or specialized state; phylogeny or ontogeny"
This is the main concept behind the definition provided by the Oxford Concise Science Dictionary (although this definition has been criticised in other aspects): "The gradual process by which the present diversity of plant and animal life arose from the earliest and most primitive organisms, which is believed to have been continuing for the past 3000 million years".
In an attempt to clearly and concisely clarify which definition they are using, creationists sometimes refer to this definition with terms such as "goo-to-you" evolution, "molecules-to-man" evolution, or "fish-to-philosopher" evolution.
It is primarily this definition of evolution that creationists believe is a invalid concept.
In modern scientific use, it is often defined as a change in gene frequency. That is, a change in the prevalence of a given variation (allele) of a gene in a population compared to other variations of that gene.
E.O. Wilson defines evolution as "any change in gene frequency in a population." Helena Curtis and N. Sue Barnes define evolution as "any change in the frequency of alleles within a gene pool from one generation to the next".
Creationists object that this definition is used to demonstrate trivial changes that are then used to claim that the entire development of life definition has been demonstrated. This definition has also been criticised by Ernst Mayr.
The gene frequency definition is an example of microevolution (meaning below the level of the species), but not macroevolution(above the level of the species)[Citation Needed] —a distinction which is important to some anti-evolutionists. Macroevolution can be seen as the multiple instances of microevolution that have added up in a population, producing a new species. This is also known as speciation. Speciation has been observed multiple times in scientific experiments, but this is not proof of evolution. Speciation is the development of a new species from an existing population, whereas evolution is the change in gene frequency in a population over time.
Increasing genetic information
Creationists define evolution as being an increase in genetic information. In order to go from the hypothesised first living cell to the variety of creatures that exist today, evolution needs to add massive quantities of genetic information, such as for hair, eyes, blood, and wings. Creationists argue that the following do not constitute evolution, because no new genetic information is generated:
- Losses of genetic information, through mutations or natural or artificial selection.
- Transfer of existing genetic information from one living thing to another.
- Duplication of existing genetic information.
These processes have all been observed, but creationists argue that what has not been observed is the generation of new genetic information.
Scientific theory, philosophy, or religion
In addition to the disagreement over the definition, there is disagreement on whether evolution constitutes a scientific theory or a philosophy or religion.
Theistic evolutionists believe that evolution has been guided by God, but most others claim that evolution is unguided and unplanned. Thirty eight Nobel prizewinners signed a 2005 statement saying that "evolution is understood to be the result of an unguided, unplanned process of random variation and natural selection.". They appeared to be answering Roman Catholic Cardinal Christoph Schönborn who said that "Evolution in the sense of common ancestry might be true, but evolution in the neo-Darwinian sense - an unguided, unplanned process of random variation and natural selection - is not." Creationists have long claimed that evolution is effectively religion. Some evolutionists have also said this. Michael Ruse is an evolutionist who testified at the Arkansas trial about teaching creation alongside evolution, that evolution was not a religion. He later wrote:
Evolution is promoted by its practitioners as more than mere science. Evolution is promulgated as an ideology, a secular religion–a full-fledged alternative to Christianity, with meaning and morality. I am an ardent evolutionist and an ex-Christian, but I must admit that in this one complaint–and Mr [sic] Gish is but one of many to make it–the literalists are absolutely right. Evolution is a religion. This was true of evolution in the beginning, and it is true of evolution still today.
...Evolution therefore came into being as a kind of secular ideology, an explicit substitute for Christianity.
Science or history
Evolutionists assert that biological evolution is a scientific theory, whilst creationists argue that biological evolution, other than the gene frequency definition, is really a claim about the history of life on the planet. They further argue that scientists are unable to apply the scientific method to past events such as evolution, as those events are no longer available for observation, measurement, and testing.
Use of different definitions
When evolution is defined as "the gradual appearance of new forms of life" over geological time, then Americans are split 50-50 over whether it has really occurred.
About 45% of Americans are Young Earth Creationists.
Advocates for the teaching of evolution as a finding of mainstream science tend to use two different meanings of "evolution".
- We have fossil evidence for evolution. It's a fact. (teacher in CNN article)
This apparently refers to the assertion that the appearance of new forms of life is supported by fossils (see carbon dating). But the context of the quote implies that the teacher was actually talking about the notion that "new species can evolve from older ones -- such as humans evolving from ancient apes." 
About half of the people who reject the materialist Theory of Evolution accept the fossil evidence of "gradual appearance" while rejecting mainstream biology's explanation that a combination of natural selection and unguided forces like mutation and copying errors is the cause.
Facts are observations, theories are models which explain those observations. Theories can never be facts, because that implies that the model itself is an observation. Due to this, theories are considered much more important than facts, being the conclusions gained from the observation of countless facts.
- See, for example, Definitions as slippery as eels in Who’s really pushing ‘bad science’?, by Jonathan Sarfati.
- Jonathan Sarfati,Ph.D., F.M. Refuting Evolution 2, Chapter 1, Argument: Creationism is religion, not science
- Quoted by Stephen E. Jones at http://members.iinet.net.au/~sejones/evolut01.html
- Implications of Evolution, p. 157, by Kerkut, G.A., quoted in Origin of life and the homochirality problem: is magnetochiral dichroism the solution? by Jonathan Sarfati.
- Quoted in What is Evolution, by Laurence Moran.
- Laurence Moran on Talk.Origins criticises the definition for excluding prokaryotes, protozoa, and fungi, and for specifying gradual changes, and other reasons.
- For example, 15 ways to refute materialistic bigotry, by Jonathan Sarfati.
- For example, Speedy species surprise, by David Catchpoole and Carl Wieland, Creation vol. 23 No. 2, p. 13.
- For example, footnote 1 in Professing creation, by Carl Wieland and Jonathan Sarfati, Creation vol. 22 No. 1, p. 36.
- Refuting Evolution 2, by Jonathan Sarfati, chapter 3.
- Referred to in CMI misunderstands evolution?.
- Wieland, Carl, Beetle Bloopers, Creation 19(3):30
- Sarfati, Jonathan, Chapter 5, Refuting Evolution 2
- Nobel Laureates urge rejection of intelligent design (LJWorld.com)
- Finding Design in Nature, by Christoph Schönborn.
- Evolution Is Religion, Not Science, by Henry Morris, Impact, May 1982.
- Quoted in Leading anti-creationist philosopher admits that evolution is a religion.
- Dawkins, Richard, Interview with Bill Moyers, 3rd December 2004.