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Line 1: + + − When used in a biological context, the word '''evolution''' refers to the change in the population of a species' inherited traits from generation to generation. These traits are the expression, or "phenotype", of genes which, at least on earth, are stored in [[DNA]]. All species on earth are thought to have come about by the mechanism of evolution. Evolution occurs as random genetic changes build up over time, and those that prove to be negative, or harmful, are weeded out as the organisms that have them are rendered less able to compete with the general population. Conversely, the organisms that had received beneficial alterations to their genes would be more suited for survival and thus more likely to live long enough to pass on those genes to another generation.+ − − + − <noinclude>[[Image:Cyanide.JPG|right|thumb|290px|A humorous look at evolution.]]</noinclude> − ===Prehistory of evolution=== − The idea that life has evolved over time is not a recent one, and [[Charles Darwin]] did not, in fact, come up with the idea of evolution in general. For example, ancient Greek philosophers, like [[Aristotle]], had ideas about biological developement.<ref>[http://www.utm.edu/research/iep/e/evolutio.htm ''Evolution''] from the Internet Encyclopedia of Philosophy</ref> Later, in Medieval times, Augustine used evolution as a basis for the philosophy of history.<ref>ibid</ref> − === Origins of the theory ===+ − − [[Erasmus Darwin]], the grandfather of Charles Darwin, was the first scientist to whom credit can be given for something starting to approach modern concepts of evolution, as noted in his contributions to botany and zoology. His writings contained many comments (mostly in footnotes and side writings) that suggested his beliefs in common descent. He concluded that vestigial organs (such as the appendix in humans) are leftovers from previous generations. The elder Darwin, however, offered no mechanism by which he believed evolution could occur.+ − === Late eighteenth-century contributions ===+ − Georges Cuvier proposed a mechanism by which the [[fossil record]] could develop over time without evolution - which by now had come into usage as a term.<ref>Biography of [http://www.ucmp.berkeley.edu/history/cuvier.html Georges Cuvier] at UC Berkeley</ref> His [[hypothesis]], '''[[catastrophism]]''', was that a series of disasters destroy all life within a limited area, and that living organisms move in to this newly opened area. This theory prefigures in some respects the modern theory of 'punctuated equilibrium'. − Lamarck was the first scientist to whom credit can be given for a theory of evolution. <ref>Biography of [http://www.ucmp.berkeley.edu/history/lamarck.html Jean-Baptiste Lamarck] at UC Berkeley</ref> His belief centered mainly around use and disuse, and the hypothesis that the more an organism used a particular part of the body, the more developed it became within a species. His theory was sound only for individuals (e.g, a weightlifter will develop larger muscles over time, but will not pass this trait onto his children.)+ − === Natural selection ===+ − At this point in time, scientists had gathered a great deal of information on species, and knew life on Earth had been around for a long time and some species had become extinct.<ref>History of Natural Selection at [http://evolution.berkeley.edu/evosite/history/naturalselection.shtml] UC Berkeley</ref>+ − Natural selection was the first theory to provide a mechanism for how evolution could work. Prior to the theory of natural selection, the concept that species changed over time existed, but there was no known mechanism for how that change occurred. Wallace and Darwin came to the conclusion, independently,<ref>See above.</ref> that competition for resources and the struggle for survival helped determine which changes became permanent and which traits were discarded. − The [[theory of evolution]] by [[natural selection]], as we know it today, was proposed in a joint paper by [[Alfred Russel Wallace]] and [[Charles Darwin]] in 1858, based on Wallace's observations in the Malay Archipelago and Darwin's experiences on the HMS Beagle. Charles Lyell's ''Principles of Geology'', which suggested slow changes over very long periods of time, also contributed to the nascent theory.<ref>[http://www.wku.edu/~smithch/wallace/FAQ.htm#path11 A brief account] of how Wallace and Darwin both published on the Theory of Natural Selection</ref> Darwin drew heavily on his knowledge of human experiments in breeding domestic animals, particularly in the realm of variations produced in the breeding of pigeons, for his understanding of how variations can develop within a population over time. Darwin laid out his theory of natural selection his books ''[[The Origin of Species]]'' and ''The Descent of Man''.<ref>[http://www.gutenberg.org/etext/2300 The Descent of Man]</ref>+ − === Other forms of selection ===+ − Although natural selection was the first mechanism proposed in evolutionary theory (and remains the most common), other forms of selection play a part as well. The most notable of these is [[sexual selection]], which occurs due to some heritable preference for a trait in breeding partners. Derivation of traits through this mechanism is driven by (usually) the female's choice in mating partner rather than direct impact on [[fitness]]. Sexual selection often leads to the rise of features which would likely not occur under natural selection, such as the tail of a male peacock or great big dangly testicles in humans and other large mammals. Indeed, in sexual selection the whole point is to prove that you are fit enough to survive ''despite'' the handicaps foisted on you by your display mechanisms, and that you are harsh enough to defend those delicious morsels 'twixt your thighs from all carnivorous comers. − It has been suggested that the perhaps unnecessarily intelligent human mind is also the result of runaway sexual selection. <ref>[http://www.thegreatdebate.org.uk/sexualselection.html Sexual selection on human mind]</ref>+ − ==Patterns in nature==+ − The field of evolutionary biology seeks to provide explanations for four conspicuous patterns that are manifest in nature. The first three concern living species, whereas the fourth relates to fossils. − − ===Genetic variation=== − According to the Genetic Variation Program arm, at the National Human Genome Research Institute, about 99.5% of human DNA is the same from person to person. The other 0.5% accounts for a number of simple and complex traits we possess. <ref>The [http://www.genome.gov/10001551 Genetic Variation Program] at the National Human Genome Research Institute</ref> − There is tremendous genetic diversity within almost all species, including humans. No two individuals have an identical DNA sequence, with the exception of identical twins or clones. This genetic variation contributes to phenotypic variation - that is, diversity in the outward appearance and behavior of individuals of the same species.+ − + − Populations must adapt to their environment to survive. − Living organisms have morphological, biochemical, and behavioral features that make them well adapted for life in the environments in which they are usually found. For example, consider the hollow bones and feathers of birds that enable them to fly, or the cryptic coloration that allows many organisms to hide from their predators. These features may give the superficial appearance that organisms were [[Intelligent design|designed by a creator]] (or engineer) to live in a particular environment. Evolutionary biology has demonstrated that adaptations arise through selection acting on a population through genetic variation.+ + − ===Divergence===+ − Species evolved along different paths from a common ancestor. − All living species differ from one another. In some cases, these differences are subtle, while in other cases the differences are dramatic. Carl Linnaeus (1707-1778) proposed a classification that is still used today with slight changes. In the modern scheme, related species are grouped into genera, related genera into families, and so on. This hierarchical pattern of relationship produces a tree-like pattern, which implies a process of splitting and divergence from a common ancestor. While Linnaeus classified species using similar physical characteristics, modern evolutionary biologists also base classification on DNA analysis, which can distinguish between superficial resemblances between species and those which are due to common ancestry.+ − ==Mechanisms of evolution==+ − Biological evolution results from changes over time in the genetic constitution of species. The accumulation of genetic variations often, but not always, produces noticeable changes in the appearance or behavior of organisms. Evolution requires both the production of variation and the spread of some variants that replace others. − ''Offspring with genetic mutations are different from their parents.''+ − :Genetic variation arises through two processes, [[mutation]] and recombination. Mutation occurs when DNA is imperfectly copied during replication, or by changes in genetic material caused by such mutagens as radiation, leading to a difference between a parent's gene and that of its offspring. Some mutations affect only one bit in the DNA; others produce rearrangements of, or changes in, large blocks of DNA. + − + − ''Genes can be shuffled between organisms.''+ − :Recombination occurs when genes from two parents are shuffled to produce an offspring, as happens in every instance of sexual reproduction. Usually the two parents belong to the same species, but sometimes (especially in bacteria) genes move between more distantly related organisms. + + − ''Not all mutations become fixed in a population.''+ − :The fate of any particular genetic variant depends on two processes, drift and selection. Drift refers to random fluctuations in gene frequency, and its effects are usually seen at the level of DNA. Ten flips of a coin do not always (or even usually) produce exactly five heads and five tails; drift refers to the same statistical issue applied to the transmission of genetic variants across generations. − − ''Natural selection guarantees that the fittest are most likely to pass on their genes.'' − :The principle of natural selection was discovered by Charles Darwin (1809-1882), and it is the process by which organisms become adapted to their environments. Selection occurs when some individual organisms have genes that encode physical or behavioral features that allow them to better harvest resources, avoid predators, reproduce successfully and such relative to other individuals that do not carry the same genes. The individuals that have more useful (adaptive) features will tend to leave more offspring than other individuals, so the responsible genes will become more common over time, leading the population as a whole to become better adapted. − − ''Distinct species diverge from one ancestor and can no longer interbreed. '' − :The process that many people find most confusing about evolution is speciation, which is not a separate mechanism at all, but rather a consequence of the preceding mechanisms played out in time and space. Speciation occurs when a population changes sufficiently over time that it becomes convenient to refer to the early and late forms by different names. Speciation also occurs when one population splits into two distinct forms that can no longer interbreed. Reproductive isolation does not generally happen in one generation; it may require many thousands of generations when, for example, one part of a population becomes geographically separated from the rest and adapts to a new environment. Given time, it is inevitable that two populations that live apart will diverge by mutation, drift, and selection until eventually their genes are no longer compatible for successful reproduction. − == Evidence for evolution ==+ − :''See [[Common descent]]'' − ==Non-biological evolution==+ − Evolutionary concepts can also be applied to non-biological processes. Universe formation and the development of languages are two such subjects. The study of [[etymology]] is one component of analyzing how languages have evolved, and parallels biological evolution, for example, in the way the same language diverges over time into two different languages when two populations that speak the same language become geographically isolated. Languages can be seen as examples of [[meme]]s, a word coined to mimic the biological "gene" in the sphere of ideas.+ − + − + − There are a number of broad arguments creationists/anti-evolutionists make. Specific claims are examined at our [[common descent]] page. − ===Random chance===+ − Often [[creationism|creationists]] ask how likely it is that all this complex life could have come about by random chance. The claim, specific or implied, is that evolution is random. Evolution as a whole isn't random. [[mutation|Mutations]] are random, but the natural selection of specific [[gene|genes]] or [[allele|alleles]] is not. (An allele is a variation of a gene. For example the eye color gene has a blue allele, a brown allele, and other alleles.) If a gene helps with survival, then it is selected by means of the survival and reproduction of the individuals carrying that gene, if it is detrimental to survival it will not be selected due to the lower rate of survival and reproduction by individuals carrying the gene. Thus, there isn't anything random about natural selection. + − Also, it's almost useless to [[Texas sharpshooter fallacy|talk about the probability of something happening after it has happened]].+ − + − Many creationists hold erroneous beliefs about evolution such as that which is expressed by the statement "I accept [[microevolution]], but not [[macroevolution]]." (This is the position of YEC [[Kent Hovind]]) Microevolution is supposed to be evolution that doesn't result in a new species and macroevolution is supposed to be evolution that does lead to a new species. This argument is akin to someone saying that while he believes that sometimes wind can erode rock, he doesn't believe it can change the rock's shape. Micro- and macroevolution describe the same process, but with a difference in operational time. If one accepts microevolution, they must also accept macroevolution since the former always leads to the latter if given enough time to work. One cannot simply accept one and not the other. In biology, macroevolution is a broad subject of which speciation is only one part. This argument against speciation may be an attempt by creationists to reserve the power to produce a species for God alone. − ===Irreducible complexity===+ − [[Irreducible complexity]] is a fancy name for Michael Behe's "watchmaker" argument. In a nutshell, irreducible complexity describes an organ (or other facet of a living thing) which the ideology's supporters claim could not have evolved in small gradual steps. It is claimed to be so complex that that it cannot be reduced into other parts. In fact, every example of irreducible complexity Behe and others have come up with has been shown to ''not'' be irreducibly complex. − ===Falsifiability===+ − For any [[theory]] to be accepted as [[scientific method|scientific]] it must be [[Falsifiability|falsifiable]]. In other words it must be capable of making statements which could theoretically be disproved. Evolution's opponents claim that the theory of Evolution does not have this property, although this claim can be [[Disproving Evolution|easily rejected]]. − ===It's only a theory===+ − Sometimes the phrase "evolution is only a theory" will be heard. this phrase rests on the common assumption that a theory is something that is possible but not proven. Science, however, defines [[Scientific theory | theory]] as ''is a testable model of the manner of interaction of a set of natural phenomena, capable of predicting future occurrences or observations of the same kind, and capable of being tested through experiment or observation,'' Which sets it at a higher level of reasoning. And if anyone says you can't directly observe evolution, send them to professor [[Richard Lenski | Lenski]]. − === Where is the overwhelming evidence? ===+ − Science doesn't work by presenting overwhelming evidence, because that leads to unquestioned dogma. Real scientists prefer to build a rickety house of cards, where each precept is vulnerable to falsification. So the question is not "where is the overwhelming evidence", but where is the one counterexample falsifying the standard model of descent with + − variation? − ==See also== + − *[[Acceptance of Evolution]] − *[[Cave man]] − *[[Common descent]] − *[[Disproving Evolution]] − *[[Evolutionary ethics]] − *[[Evolutionism]] − *[[Intelligent Design]] − *[[Natural selection]] − *[[Project Steve]] − *[[Scientific evidence of evolution being a hoax, and God's existence]] − *[[Types of evolution]] − *[[Unguided evolution]] − *[[Young Earth Creationism]] − *[[Talk:Evolution/vandalism|Vandalism to this page]] − ==External links==+ − *[http://www.talkorigins.org/ Talk Origins Archive] − *[http://www.ncseweb.org/ National Center for Science Education] − *[http://www.sciam.com/article.cfm?id=15-answers-to-creationist Fifteen answers to creationist nonsense] − ===Historical Writings=== − *[http://quod.lib.umich.edu/cgi/t/text/text-idx?sid=a894df5d7ce636ef856ac34302166419&c=moa&idno=AJP5195.0001.001&view=toc ''Contributions to the theory of natural selection. A series of essays''] by Alfred Russel Wallace − *[http://www.gutenberg.org/etext/14558 ''Darwinism''] (1889) by Alfred Russel Wallace − *[http://www.gutenberg.org/etext/2300 ''The Decent of Man''] by Charles Darwin − *[http://www.gutenberg.org/etext/1228 ''On the Origin of Species By Means of Natural Selection''] by Charles Darwin − + − # Wile, Jay L. '''Exploring Creation With General Science'''. Anderson: Apologia Educational Ministries, Inc. 2000 − # [http://evolution.berkeley.edu/ Understanding Evolution] − − ==Footnotes== − [[category:Evolution]]+ − [[Category:Articles needing RWification]] − [[Category:High priority]] − − − − {{Evonav}} − {{keyword|evokey= Evolution}}
Definition of evolution (view source)
Revision as of 15:13, November 27, 2008
, 15:13, November 27, 2008Reverted edits by AliceM (Talk) to last version by ArnoldFriend
The word '''"evolution"''' as used in [[Biology]] and in the [[Origins debate]] has multiple meanings. It is not easy to keep track of which meaning is being used.
Several different meanings have been and still are used, and this is itself part of the controversy over the [[Theory of Evolution]].
[[Creationist]]s charge that evolutionists often equivocate between different meanings<ref>See, for example, [http://www.creationontheweb.com/content/view/2891#Definitions Definitions as slippery as eels] in ''Who’s really pushing ‘bad science’?'', by Jonathan Sarfati.</ref>, while [[evolutionist]]s acknowledge that not clearly defining the term leads to confusion.<ref>[http://www.talkorigins.org/faqs/evolution-definition.html What is Evolution?] by Laurence Moran.</ref>
<noinclude>{{Evolution}}</noinclude>
==History==
== Etymology==
The word ''evolution'' comes from Latin, meaning ''unrolling''<ref>[http://www.askoxford.com/concise_oed/evolution?view=uk AskOxford.com.</ref>, and refers to any gradual change. But it has more precise definitions in popular and scientific use.
The first significant step in the theory of evolution was made by Carl Linnaeus.<ref>[http://library.thinkquest.org/C004367/eh1.shtml Brief history of Evolutionary Thought]</ref> His leading contribution to science was his creation of the [[Linnaean taxonomy|binomial system of nomenclature]] - in layman's terms, the two part name given to species, such as ''Homo sapiens'' for humans. He, like other biologists of his time, believed in the fixity of the species, and in the ''scala naturae'', or the scale of life. His ideas were consistent with the [[Judeo-Christian|Judeo-Christan]] teachings of his time.
=== Universal ===
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."<ref>Quoted by Stephen E. Jones at [http://members.iinet.net.au/~sejones/evolut01.html http://members.iinet.net.au/~sejones/evolut01.html]</ref>
=== 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"<ref>''Implications of Evolution'', p. 157, by Kerkut, G.A., quoted in [http://www.creationontheweb.com/content/view/1627 Origin of life and the homochirality problem: is magnetochiral dichroism the solution?] by Jonathan Sarfati.</ref>
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"<ref Name="TO">Quoted in [http://www.talkorigins.org/faqs/evolution-definition.html What is Evolution], by Laurence Moran.</ref>
This is the main concept behind the definition provided by the Oxford Concise Science Dictionary (although this definition has been criticised in other aspects<ref>Laurence Moran on Talk.Origins criticises the definition for excluding [[prokaryotes]], protozoa, and fungi, and for specifying ''gradual'' changes, and other reasons.</ref>): "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".<ref name="TO" />
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<ref>For example, [http://www.creationontheweb.com/content/view/2610 15 ways to refute materialistic bigotry], by Jonathan Sarfati.</ref>, "molecules-to-man" evolution,<ref>For example, [http://www.creationontheweb.com/content/view/403/ Speedy species surprise], by David Catchpoole and Carl Wieland, ''Creation'' vol. 23 No. 2, p. 13.</ref> or "fish-to-philosopher" evolution<ref>For example, footnote 1 in [http://www.creationontheweb.com/content/view/281 Professing creation], by Carl Wieland and Jonathan Sarfati, ''Creation'' vol. 22 No. 1, p. 36.</ref>.
It is primarily evolution of this definition that creationists disagree with.
===Adaptation===
=== Gene frequency ===
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"<ref Name="TO" />
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.<ref>[http://www.creationontheweb.com/content/view/3262/ Refuting Evolution 2], by Jonathan Sarfati, chapter 3.</ref> This definition has also been criticised by [[Ernst Mayr]].<ref>Referred to in [http://www.creationontheweb.com/content/view/2722/ CMI misunderstands evolution?].</ref>
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){{fact}}<!-- Is this really the distinction between micro- and macro-? And is a change of gene frequency really equal to micro-? --> —a distinction which is important to some anti-evolutionists.
=== Increasing genetic information ===
Creationists define evolution as being an increase in genetic [[information]].<ref>Wieland, Carl, [http://www.creationontheweb.com/content/view/599 Beetle Bloopers], ''Creation'' 19(3):30</ref> 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.<ref>Sarfati, Jonathan, [http://www.creationontheweb.com/content/view/3268 Chapter 5, Refuting Evolution 2]</ref>
== 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 evolution]]ists 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." <ref>[http://www2.ljworld.com/news/2005/sep/15/nobel_laureates_urge_rejection_intelligent_design/ Nobel Laureates urge rejection of intelligent design] (LJWorld.com)</ref>.
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." <ref>[http://www.nytimes.com/2005/07/07/opinion/07schonborn.html?ex=1278388800&en=95804819e49f4832&ei=5090&partner=rssuserland&emc=rss Finding Design in Nature], by Christoph Schönborn. </ref>
[[creationism|Creationists]] consequently confuse the biological and non-biological meanings of the word "evolution" and they claim that the [[Theory of Evolution]] includes the origin of the universe and the origin of life. The biological theory of evolution as proposed by Darwin and others has nothing to say about either the origin of the universe or [[Abiogenesis|the origin of life]] on Earth.
Creationists have long claimed that evolution is effectively religion<ref>[http://www.icr.org/article/201/ Evolution Is Religion, Not Science], by Henry Morris, ''Impact'', May 1982.</ref> Some evolutionists have also admitted 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:<ref>Quoted in [http://www.creationontheweb.com/content/view/4139/105/ Leading anti-creationist philosopher admits that evolution is a religion].</ref>{{QuoteBox|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.<br /><br />...Evolution therefore came into being as a kind of secular ideology, an explicit substitute for Christianity.}}
==Broad anti-evolution arguments==
== Science or history ==
Evolutionists assert that biological evolution is a scientific theory<ref> NCSE [http://www.ncseweb.org/resources/articles/8408_statements_from_scientific_and_12_19_2002.asp National Center for Science Education] Accessed October 7, 2007</ref>, 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.
[[Richard Dawkins]] seemed to acknowledge that evolution is unobserved history when he said that "Evolution has been observed. It's just that it hasn't been observed while it's happening."<ref>Dawkins, Richard, [http://www.pbs.org/moyers/faithandreason/print/dawkins_print.html Interview with Bill Moyers], 3rd December 2004.<!-- probably: it's actually listed as "12.03.04", which could be 12th March, in theory. --></ref>
===Microevolution and macroevolution===
== 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 [[radiometric dating|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." [http://archives.cnn.com/2000/US/03/08/creationism.vs.evolution/]
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.
==Sources==
==Notes==
<references/>
<references/>
[[Category:Origins Debate]]
[[Category:Reality]]