Objections to evolution

Objections to evolution have been raised since various evolutionary ideas came to be debated around the start of the nineteenth century. The ideas gained vast popular audiences, and when Charles Darwin brought out his 1859 book The Origin of Species he gradually convinced most of the scientific community that evolution was a valid hypothesis. In the 1930s Darwin's theory of natural selection came to be seen as the primary explanation of the process of evolution. The existence of evolutionary processes, and the ideas of the modern evolutionary synthesis that explain them, although opposed by creationists, have since been uncontroversial among biologists.

Since then, nearly all criticisms of evolution have come from religious, rather than scientific, sources. However, most Christians believe in God as Creator, while also accepting scientific evolution as a natural process. A minority of Christians rejected evolution from its outset as "heresy", but most attempted to reconcile scientific evolution with Biblical accounts of creation. Islam accepts the natural evolution of plants and animals, but the origin of man is contested and no consensus has emerged. The resultant creation-evolution controversy has been a recurring point of conflict between religion and science, most prevalent in certain, generally more conservative, regions of the United States.

In contrast to earlier objections to evolution that were either strictly scientific or explicitly religious, recent objections to evolution have frequently blurred the distinction. Movements such as Creation Science and Intelligent Design attack the scientific basis of evolution and argue that there is greater scientific evidence for the design of life by God or another intelligent being. Many of the arguments against evolution have become widespread, including objections to evolution's evidence, methodology, plausibility, morality, and scientific acceptance. However, these arguments are not accepted by the scientific community.

Defining evolution


One of the main sources of confusion and ambiguity in the creation-evolution debate is the definition of evolution itself. In the context of biology, evolution is simply the genetic change in populations of organisms over successive generations. However, the word has a number of different meanings in different fields, from evolutionary computation to chemical evolution to sociocultural evolution to stellar and galactic evolution. It can even refer to metaphysical evolution, spiritual evolution, or any of a number of evolutionist philosophies. When biological evolution is mistakenly conflated with other evolutionary processes, it can result in errors such as the claim that modern evolutionary theory says anything about abiogenesis or the Big Bang.

In colloquial contexts, evolution can refer to any sort of progressive development, and often bears a connotation of gradual improvement: evolution is understood as a process that results in greater quality or complexity. This common definition, when misapplied to biological evolution, leads to frequent misunderstandings. For example, the idea of devolution ("backwards" evolution) is a result of erroneously assuming that evolution is directional or has a specific goal in mind (cf. orthogenesis). In reality, the evolution of an organism does not entail objective improvement other than increasing "fitness" in its environment; and its suitability is only defined in relation to this environment. Biologists do not consider any one species, such as humans, to be more "highly evolved" or "advanced" than another. Humans are led to believe otherwise by our tendency to evaluate nonhuman organisms according to our own, anthropocentric standards.

Nor does evolution require that organisms become more complex. Although the history of life reflects a gradual trend towards a larger number of increasingly complex organisms, this is no more a necessary consequence of evolution than the existence of Mars is a necessary consequence of gravity; rather, it is a consequence of the specific circumstances of evolution on Earth, which frequently made greater complexity advantageous, and thus naturally selected for. Depending on the situation, organisms' complexity can either increase, decrease, or stay the same, and all three of these trends have been observed in biological evolution; indeed, decreasing complexity is exceedingly common.

Creationist sources frequently define evolution according to its colloquial, rather than scientific, meaning. As a result, many attempts to rebut evolution are actually straw men that do not address the claims of evolutionary biology. This also means that advocates of creationism and evolution often simply speak at odds with each other.

History of objections


The earliest objections to Darwinian evolution were both scientific and religious. Although most of Darwin's contemporaries came to accept the transmutation of species based upon fossil evidence, the specific evolutionary mechanism which Darwin provided, natural selection, was actively disputed by alternative theories such as Lamarckism and orthogenesis. Darwin's gradualistic account was also opposed by saltationism and catastrophism. Additionally, the specific hereditary mechanism Darwin provided, pangenesis, lacked any supporting evidence. In the early 20th century, pangenesis was replaced by Mendelian inheritance, leading to the rise of the modern evolutionary synthesis. Darwinism, in its revised form as "Neo-Darwinism", rose to universal acceptance among biologists with the help of new evidence, such as genetics, which confirmed Darwin's predictions and refuted the competing theories.

Since then, although disagreements and new ideas have continued over certain specific points, such as punctuated equilibrium, evolutionary theory itself has been entirely uncontested in the field of biology, and indeed is commonly described as the "cornerstone of modern biology".

Many early religious objections to Darwin's theory, in contrast, continue to thrive to this day. The idea that species had developed over time by natural processes from a common ancestor seemed to contradict the Genesis account of Creation. Many believers in Biblical infallibility thus attacked Darwinism as heretical. The most common early religious arguments against evolution were Paley's watchmaker analogy, an argument from design still heavily utilized by the modern creationist movement. The idea of organs developing incrementally was also objected to, in the form of questions like "what use is half a wing?" or "what use is half an eye?" This, however, is a 'straw man' argument: evolution does not postulate half an eye, but an eye that is half as efficient. The incremental improvement refers to an organ's ability, rather than its structure.

In the 20th century, the wide acceptance of evolution by the scientific community led to frequent conflicts between creationism and evolution, comprising the creation-evolution controversy. Most of these conflicts have centered on the objections of Christian fundamentalists in the United States to the teaching of evolution in public schools. Although early objections simply dismissed evolution for seeming to contradict the Bible, this argument was invalidated when the Supreme Court ruled in Epperson v. Arkansas that forbidding the teaching of evolution on religious grounds violated the Establishment Clause.

Since then, many creationists have developed more sophisticated objections to evolution, alleging that it is unscientific, that its teaching infringes on creationists' religious freedoms, that belief in evolution is religious, or that belief in God is scientific. Creationists have appealed to democratic principles of fairness, arguing that evolution is controversial, and that science classrooms should therefore "Teach the Controversy" and let students decide what to believe for themselves. These objections to evolution culminated in the intelligent design movement in the 1990s, which has gained significant public support in the United States.

Objections to evolution's scientific acceptance
Many recent objections to evolutionary theory have focused on downplaying its scientific acceptance, attempting to discredit or invalidate it in order to advocate creationism as an equally good, or superior, explanation for life's diversity. Creationists often argue, for example, that evolution is unproven, non-factual, or controversial.

Evolution is just a theory, not a fact
Critics of evolution frequently assert that evolution is "just a theory", with the intent of emphasizing evolution's unproven nature, or of characterizing it as a matter of opinion rather than of fact or evidence. This reflects a misunderstanding of the meaning of theory in a scientific context: whereas in colloquial speech a theory is a conjecture or guess, in science a theory is simply an explanation or model of the world that makes testable predictions. When evolution is used to describe a theory, it refers to an explanation for the diversity of species and their ancestry. An example of evolution as theory is the modern synthesis of Darwinian natural selection and Mendelian inheritance. As with any scientific theory, the modern synthesis is constantly debated, tested, and refined by scientists. There is an overwhelming consensus in the scientific community that it remains the only robust model that accounts for the known facts concerning evolution.

Critics also state that evolution is not a fact. In science, a fact is a verified empirical observation; in colloquial contexts, however, a fact can simply refer to anything for which there is overwhelming evidence. For example, in common usage theories such as "the Earth revolves around the Sun" and "objects fall due to gravity" may be referred to as "facts", even though they are purely theoretical. From a scientific standpoint, therefore, the theory of evolution may be called a "fact" for the same reason that gravity can: under the technical definition, this applies to the observed process of evolution occurring whenever a population of organisms genetically changes over time, whereas under the colloquial definition, this applies to evolutionary theory's well-established nature. Thus, evolution is widely considered both a theory and a fact by scientists.

Similar confusion is involved in objections that evolution is "unproven"; strict proof is possible only in logic and mathematics, not science, so this is trivially true, and no more an indictment of evolution than calling it a "theory" is. The confusion arises, however, in that the colloquial meaning of proof is simply "compelling evidence", in which case scientists would indeed consider evolution "proven". The distinction is an important one in philosophy of science, as it relates to the lack of absolute certainty in all empirical claims, not just evolution.

Evolution is controversial or contested
One of the most recent major objections to evolution is in a sense self-fulfilling: it argues that evolution is controversial or contentious. Unlike past creationist arguments which sought to abolish the teaching of evolution altogether, this argument makes the weaker claim that evolution, being controversial, should be presented alongside other, alternative views, and students should be allowed to evaluate and choose between the options on their own. This appeal to "fairness" and a more democratic, "balanced" approach in which conflicting views are given "equal time" appeals to many American creationists, and has been endorsed by President George W. Bush.

This objection forms the basis of the "Teach the Controversy" campaign, an attempt by the Discovery Institute to promote the teaching of intelligent design in public schools. This in turn forms a major part of the Institute's "wedge strategy", an attempt to gradually undermine evolution and ultimately to "reverse the stifling materialist world view and replace it with a science consonant with Christian and theistic convictions".

Scientists and U.S. courts have rejected this objection on the grounds that science is not based on appeals to popularity, but on evidence. The scientific consensus of biologists, not popular opinion or "fairness", determines what is considered acceptable science, and it is argued that although evolution is clearly controversial in the public arena, it is entirely uncontroversial among experts in the field.

In response, creationists have disputed the level of scientific support for evolution. The Discovery Institute has gathered over 600 scientists since 2001 to sign "A Scientific Dissent From Darwinism" in order to show that there are a number of scientists who dispute Darwinian evolution. This statement did not profess outright disbelief in Darwinian evolution, but expressed skepticism as to the ability of "random mutation and natural selection to account for the complexity of life." Several counter-petitions have been launched in turn, including A Scientific Support for Darwinism, which gathered over 7,000 signatures in four days, and Project Steve, a tongue-in-cheek petition that has gathered 868 (as of March 18, 2008) evolution-supporting scientists named "Steve".

Creationists have argued for over a century that evolution is "a theory in crisis" that will soon be overturned. This is based on a variety of objections to evolution, including that it lacks reliable evidence or violates natural laws. These objections have been rejected by most scientists, as have claims that intelligent design, or any other creationist explanation, meets the basic scientific standards that would be required to make them scientific "alternatives" to evolution. It is also argued that even if evidence against evolution exists, it is a false dilemma to characterize this as evidence for intelligent design.

A similar objection to evolution is that certain scientific authorities &mdash; mainly pre-modern ones &mdash; have doubted or rejected evolution. Most commonly, it is argued that Darwin "recanted" on his deathbed, a myth originating from the Lady Hope Story. These objections are generally rejected as appeals to authority. Even if this myth were true, it would hold no bearing on the merit of the theory itself.

Objections to evolution's scientific status
A common neocreationist objection to evolution is that evolution does not adhere to normal scientific standards &mdash; that it isn't genuinely scientific. It is argued that evolution does not follow the scientific method, and therefore should not be taught in science classes, or at least should be taught alongside other views (i.e., creationism). These objections often deal with the very nature of Darwinian evolution and the scientific method.

Evolution is a religion
Creationists commonly argue against evolution on the grounds that "evolution is a religion; it is not a science". The purpose of this criticism is to undermine the "higher ground" biologists claim in debating creationists, and to reframe the debate from being between science (evolution) and religion (creationism) to being between two equally religious beliefs &mdash; or, in some cases, even to argue that evolution is religious, while some form of creationism (typically intelligent design) is not. Those that oppose evolution frequently refer to supporters of evolution as "Evolutionists" or "Darwinists".

The arguments for evolution being a religion generally amount to arguments by analogy: it is argued that evolution and religion have one or more things in common, and that therefore evolution is a religion. Examples of alleged similarities include claims that evolution is based on faith, that supporters of evolution revere Darwin as a prophet, and that supporters of evolution dogmatically reject alternative suggestions out-of-hand. These claims have become more popular in recent years as the neocreationist movement has sought to distance itself from religion, thus giving it more reason to make use of a seemingly anti-religious analogy.

In response, supporters of evolution have argued that no scientist's claims, including Darwin's, are treated as sacrosanct, as shown by the aspects of Darwin's theory that have been rejected or revised by scientists over the years, to form "Neo-Darwinism". The claim that evolution relies on faith, often based on the idea that evolution has never been observed, is likewise rejected on the grounds that evolution has strong supporting evidence, and therefore does not require faith.

In general, the argument that evolution is religious has been rejected on the grounds that religion is not defined by how dogmatic, closed-minded, or zealous its adherents are, but by its spiritual or supernatural beliefs. In addition to disputing the idea that evolution is dogmatic or based on faith, thus, supporters of evolution accuse creationists of equivocating between the strict definition of religion and its colloquial usage to refer to anything that is enthusiastically or dogmatically engaged in. U.S. courts have also rejected this objection:

"Assuming for the purposes of argument, however, that evolution is a religion or religious tenet, the remedy is to stop the teaching of evolution, not establish another religion in opposition to it. Yet it is clearly established in the case law, and perhaps also in common sense, that evolution is not a religion and that teaching evolution does not violate the Establishment Clause."

A related claim is that evolution is atheistic; creationists sometimes merge the two claims and describe evolution as an "atheistic religion" (cf. humanism). This argument against evolution is also frequently generalized into a criticism of all science; it is argued that "science is an atheistic religion", on the grounds that its methodological naturalism is as unproven, and thus as "faith-based", as the supernatural and theistic beliefs of creationism.

Evolution is unfalsifiable
A statement is considered falsifiable if there is an observation or a test that could be made that would demonstrate that the statement is false. Evolution is considered falsifiable because it makes many predictions which, if they were contradicted by the evidence, would falsify evolution. In contrast, many religious beliefs are not falsifiable, because no testable prediction has been made about the supernatural.

Many creationists (for example Henry M. Morris ) have claimed that evolution is unfalsifiable. They claim that any fact can be fit into the evolutionary framework, and that therefore it is impossible to demonstrate evolution is wrong. Evolution is not in fact unfalsifiable, but it may appear to be so because it is so widely confirmed, and so foundational, that the likelihood of any evidence disproving it wholesale (as opposed to merely refining it) has become increasingly improbable and difficult to the point of virtual impossibility – as is the case with theories such as gravitation.

Others claim that past events of speciation are not observable and repeatable, and therefore evolution is not falsifiable. In 1976, Popper himself said that "Darwinism is not a testable scientific theory but a metaphysical research programme". However, Popper later recanted, and offered a more nuanced view of its status:

"However, Darwin's own most important contribution to the theory of evolution, his theory of natural selection, is difficult to test. There are some tests, even some experimental tests; and in some cases, such as the famous phenomenon known as 'industrial melanism', we can observe natural selection happening under our very eyes, as it were. Nevertheless, really severe tests of the theory of natural selection are hard to come by, much more so than tests of otherwise comparable theories in physics or chemistry."

In response to this criticism of evolution, numerous examples of potential ways to falsify evolution have been proposed. J.B.S. Haldane, when asked what hypothetical evidence could disprove evolution, replied "fossil rabbits in the Precambrian era". Numerous other potential ways to falsify evolution have also been proposed. For example, the evolution of chimpanzees and humans from a common ancestor predicts a (geologically) recent common ancestor. Numerous transitional fossils have since been found. The assertion of common descent could also have been disproven with the invention of DNA analysis. If true, human DNA should be far more similar to chimpanzees than other mammals. If not, then common descent is falsified. DNA analysis has shown that humans and chimpanzees share a large percentage of their DNA (between 95% to 99.4% depending on the measure). Hence, human evolution has passed a falsifiable test.

A related claim, also once used, but then abandoned, by Popper, is that natural selection is tautological. Specifically, it is often argued that the phrase "survival of the fittest" is a tautology, in that fitness is defined as ability to survive and reproduce. However, this phrase, first used by Herbert Spencer in 1864, is rarely used by biologists. Additionally, fitness is more accurately defined as the state of possessing traits that make survival more likely; this definition, unlike simple "survivability", avoids being trivially true.

Similarly, it is argued that evolutionary theory is circular reasoning, in that evidence is interpreted as supporting evolution, but evolution is required to interpret the evidence. An example of this is the claim that geological strata are dated through the fossils they hold, but that fossils are in turn dated by the strata they are in. However, in most cases strata are not dated by their fossils, but by their position relative to other strata and by radiometric dating, and many strata were dated before the theory of evolution was formulated.

In his book, Abusing Science: The Case Against Creationism, philosopher of science Philip Kitcher specifically addresses the "falsifiability" question by taking into account notable philosophical critiques of Popper by Carl Gustav Hempel and Willard Van Orman Quine that reject his definition of theory as a set of falsifiable statements is wrong. As Kitcher points out, if one took a strictly Popperian view of “theory,” observations of Uranus when first discovered in 1781 would have “falsified” Newton’s celestial mechanics. Rather, people suggested that another planet influenced Uranus’ orbit – and this prediction was indeed eventually confirmed. Kitcher agrees with Popper that “there is surely something right in the idea that a science can succeed only if it can fail.” But he insists that we view scientific theories as consisting of an “elaborate collection of statements,” some of which are not falsifiable, and others – what he calls “auxiliary hypotheses,” which are.

According to Kitcher, good scientific theories must have three features: (1) unity: “A science should be unified …. Good theories consist of just one problem-solving strategy, or a small family of problem-solving strategies, that can be applied to a wide range of problems” (1982: 47). (2) Fecundity: “A great scientific theory, like Newton’s, opens up new areas of research. …. Because a theory presents a new way of looking at the world, it can lead us to ask new questions, and so to embark on new and fruitful lines of inquiry …. Typically, a flourishing science is incomplete. At any time, it raised more questions than it can currently answer. But incompleteness is no vice. On the contrary, incompleteness is the mother of fecundity …. A good theory should be productive; it should raise new questions and presume that those questions can be answered without giving up its problem-solving strategies” (1982: 47-48). (3) auxiliary hypothesis that are independently testable: “An auxiliary hypothesis ought to be testable independently of the particular problem it is introduced to solve, independently of the theory it is designed to save” (1982: 46) (e.g. the evidence for the existence of Neptune is independent of the anomalies in Uranus’s orbit).

Like other definitions of theories, including Popper’s, Kitcher makes it clear that a good theory includes statements that have (in his terms) “observational consequences.”  But, like the observation of irregularities in Uranus’s orbit, falsification is only one possible consequence of an observation. The production of new hypotheses is another possible – and equally important – observational consequence. Kitcher’s account of a good theory of course is based not only on his understanding of how physical sciences work. He is also taking into account the way the life sciences work.

From Kitcher’s point of view, Darwinian theory not only meets the three conditions for a good scientific theory; it is without question an extraordinarily successful theory:


 * The heart of Darwinian evolutionary theory is a family of problem-solving strategies, related by their common employment of a particular style of historical narrative. A Darwinian history is a piece of reasoning of the following general form.  The first step consists in a description of an ancestral population of organisms.  The reasoning proceeds by tracing the modification of the population through subsequent generations, showing how characteristics were selected, inherited, and became prevalent.  Reasoning like this can be used to answer a host of biological questions.


 * The same kind of story can be told again and again to answer all sorts of questions about all sorts of living things. Evolutionary theory is unified because so many diverse questions … can be addressed by advancing Darwinian histories.  Moreover, these narratives constantly make claims that are subject to independent check.


 * Darwin not only provided a scheme for unifying the diversity of life. He also gave a structure to our ignorance.  After Darwin, it was important to resolve general issues about the presuppositions of Darwinian histories.  The way in which biology should proceed had been made admirably plain, and it was clear that biologists had to tackle questions for which they had, as yet, no answers.

Objections to evolution's evidence
Objections to evolution's evidence tend to be more concrete and specific, often involving direct analysis of evolutionary biology's methods and claims.

Evolution has never been observed


A common claim of creationists is that evolution has never been observed. Challenges to such objections often come down to debates over how evolution is defined. Under the conventional biological definition of evolution, it is a simple matter to observe evolution occurring. Evolutionary processes, in the form of populations changing their genetic composition from generation to generation, have been observed in many different scientific contexts, including the evolution of fruit flies and bacteria in laboratory settings, and of tilapia in the field.

In response to such examples, many creationists specify that they are objecting only to macroevolution, not microevolution: most creationist organizations do not dispute the occurrence of short-term, relatively minor evolutionary changes, such as that observed even in dog breeding. Rather, they dispute the occurrence of major evolutionary changes over long periods of time, which by definition cannot be directly observed, only inferred from microevolutionary processes and the traces of macroevolutionary ones.

However, as biologists define macroevolution, both microevolution and macroevolution have been observed. Speciations, for example, have been directly observed many times, despite popular misconceptions to the contrary. Additionally, modern evolutionary synthesis draws little distinction between macroevolution and microevolution, considering the former to simply be the latter on a larger scale.

Additionally, past macroevolution can be inferred from historical traces. Transitional fossils, for example, provide plausible links between several different groups of organisms, such as Archaeopteryx linking birds and dinosaurs, or the recently-discovered Tiktaalik linking fish and amphibians. Creationists dispute such examples in a variety of ways, from asserting that such fossils are hoaxes or that they belong exclusively to one group or the other, to asserting that there should be far more evidence of obvious transitional species. Darwin himself found the paucity of transitional species to be one of the greatest weaknesses of his theory: "Why is not every geological formation and every stratum full of such intermediate links? Geology assuredly does not reveal any such finely graduated organic chain, and this perhaps is the greatest objection which can be urged against my theory." However, the number of clear transitional fossils has increased enormously since Darwin's day, and this problem has been largely resolved with the advent of the theory of punctuated equilibrium, which predicts a primarily stable fossil record broken up by occasional major speciations.

Creationists counter that even observed speciations and transitional fossils are insufficient evidence for the vast changes summarized by such phrases as "fish to philosophers" or "particles to people". As more and more compelling direct evidence for inter-species and species-to-species evolution has been gathered, creationists have redefined their understanding of what amounts to a "created kind", and have continued to insist that more dramatic demonstrations of evolution be experimentally produced. One version of this objection is "Were you there?", popularized by Ken Ham. It argues that because no one except God could directly observe events in the distant past, scientific claims are just speculation or "story-telling".

In fields such as astrophysics or meteorology, where direct observation or laboratory experiments are difficult or impossible, the scientific method instead relies on observation and logical inference. In such fields, the test of falsifiability is satisfied when a theory is used to predict the results of new observations. When such observations contradict a theory's predictions, it may be revised or discarded if an alternative better explains the observed facts. For example, Newton's theory of gravitation was replaced by Einstein's theory of General Relativity when the latter was observed to more precisely predict the orbit of Mercury.

Past evidence for evolution has been overturned


A related objection is that evolution is based on unreliable evidence. This objection goes further than the less substantial "evolution isn't proven" arguments, claiming that evolution isn't even well-evidenced. Typically, this is either based on the argument that evolution's evidence is full of frauds and hoaxes, that current evidence for evolution is likely to be overturned because some past evidence has been, or that certain types of evidence are inconsistent and dubious.

Arguments against evolution's reliability are thus often based on analyzing the history of evolutionary thought or the history of science in general. Creationists point out that in the past, major scientific revolutions have overturned theories that were at the time considered near-certain. They thus claim that current evolutionary theory is likely to undergo such a revolution in the future, on the basis that it is a "theory in crisis" for one reason or another.

Critics of evolution commonly appeal to past scientific hoaxes such as the Piltdown Man forgery. It is argued that because scientists have been mistaken and deceived in the past about evidence for various aspects of evolution, some or all of the current evidence for evolution is likely to also be based on fraud and error. Much of the evidence for evolution has been accused of being fraudulent at various times, including Archaeopteryx, peppered moth melanism, and Darwin's finches; these claims have been subsequently refuted.

It has also been claimed that certain former pieces of evidence for evolution which are now considered out-of-date and erroneous, such as Ernst Haeckel's 19th-century embryo drawings, were not merely errors but frauds; biology textbooks have drawn significant criticism from both opponents and supporters of evolution for continuing to reproduce such evidence after it has been debunked.

Evolution's evidence is unreliable or inconsistent
Creationists claim that evolution relies on certain types of evidence that do not give reliable information about the past. It is argued, for example, that radiometric dating, the technique of evaluating a material's age based on the radioactive decay rates of certain isotopes, generates inconsistent, and thus unreliable, results. Radiocarbon dating, based on the Carbon 14 isotope, has been particularly criticized. It is argued that radiometric decay relies on a number of unwarranted assumptions, such as the principle of uniformitarianism, consistent decay rates, or rocks acting as closed systems. This argument has been scientifically dismissed on the grounds that a variety of independent methods have confirmed the reliability of radiometric dating as a whole; additionally, different radiometric dating methods and techniques have independently confirmed each other's results.

Another form of this objection is that fossil evidence is not reliable. This is based on a much wider range of claims. These include that there are too many "gaps" in the fossil record, that fossil-dating is cyclic (see evolution is unfalsifiable), or that certain fossils, such as polystrate fossils, are seemingly "out of place". It is argued that certain features of evolution support creationism's catastrophism (cf. Great Flood), rather than evolution's gradualistic punctuated equilibrium.

Objections to evolution's plausibility
Some of the oldest and most common objections to evolution dispute whether evolution can truly account for all the apparent complexity and order in the natural world. It is argued that evolution is too unlikely or otherwise lacking to account for various aspects of life, and therefore that an intelligence&mdash;God&mdash;must at the very least be appealed to for those specific features.

Life is too unlikely to arise by chance


An exceedingly prevalent objection to evolution is that it is simply too unlikely for life, in all its complexity and apparent "design", to have arisen "by chance". It is argued that the odds of life having arisen without a deliberate intelligence guiding it are so astronomically low that it is unreasonable to not infer an intelligent designer from the natural world, and specifically from the diversity of life. A more extreme version of this argument is that evolution cannot create complex structures. The idea that it is simply too implausible for life to have evolved on Earth is often encapsulated with a quotation that the "probability of life originating on earth is no greater than the chance that a hurricane sweeping through a scrap-yard would have the luck to assemble a Boeing 747" (a claim attributed to astrophysicist Fred Hoyle and known as Hoyle's fallacy ).

This view is thus invariably justified with arguments from analogy. The basic idea of this argument for a designer is the teleological argument, an argument for the existence of God based on the perceived order or purposefulness of the universe. A common way of using this as an objection to evolution is by appealing to the 18th-century philosopher William Paley's watchmaker analogy, which argues that certain natural phenomena are analogical to a watch (in that they are ordered, or complex, or purposeful), which means that, like a watch, they must have been designed by a "watchmaker" &mdash; an intelligent agent. This argument forms the core of intelligent design, a neocreationist movement seeking to establish certain variants of the design argument as legitimate science, rather than as philosophy or theology, and have them be taught alongside evolution.

This objection is fundamentally an argument by lack of imagination, or argument from incredulity: a certain explanation is seen as being counter-intuitive, and therefore an alternate, more intuitive explanation is appealed to instead. Supporters of evolution generally respond by arguing that evolution is not based on "chance", but on predictable chemical interactions: natural processes, rather than supernatural beings, are the "designer". Although the process involves some random elements, it is the non-random selection of survival-enhancing genes that drives evolution along an ordered trajectory. The fact that the results are ordered and seem "designed" is no more evidence for a supernatural intelligence than the apparent design of snowflakes is. It is also argued that there is insufficient evidence to make statements about the plausibility or implausibility of abiogenesis, that certain structures demonstrate poor design, and that the implausibility of life evolving exactly as it did is no more evidence for an intelligence than the implausibility of a deck of cards being shuffled and dealt in a certain random order.

It has also been noted that arguments against some form of life arising "by chance" are really objections to nontheistic abiogenesis, not to evolution. Indeed, many arguments against "evolution" are based on the misconception that abiogenesis is a component of, or necessary precursor to, evolution. Similar objections sometimes conflate the Big Bang with evolution.

Christian apologist and philosopher Alvin Plantinga, a supporter of intelligent design, has formalized and revised the improbability argument as the evolutionary argument against naturalism, which asserts that it is irrational to reject a supernatural, intelligent creator because the apparent probability of certain faculties evolving is so low. Specifically, Plantinga claims that evolution cannot account for the rise of reliable reasoning faculties. Plantinga argues that whereas a God would be expected to create beings with reliable reasoning faculties, evolution would be just as likely to lead to unreliable ones, meaning that if evolution is true, it is irrational to trust whatever reasoning one relies on to conclude that it is true. This novel epistemological argument has been criticized similarly to other probabilistic design arguments. It has also been argued that rationality, if conducive to survival, is more likely to be selected for than irrationality, making the natural development of reliable cognitive faculties more likely than unreliable ones.

Evolution does not explain certain human behaviors
It is frequently argued that a great weakness of evolutionary theory is that it does not, or cannot, explain a certain aspect of the natural world. Although there is broad agreement that certain aspects of life remain unexplained, some creationists go one step further and argue that evolution should be abandoned altogether because of the phenomena it doesn't explain. Many argue that an alternative explanation, such as intelligent design, can explain the things which evolution cannot. For example, Michael Behe has argued that current evolutionary theory can't account for certain complex structures, particularly in microbiology. On this basis, Behe argues that such structures were "purposely arranged by an intelligent agent" (see evolution is too implausible and argument from incredulity).

In addition to complex structures and systems, among the many phenomena that critics variously claim evolution cannot explain are consciousness, free will, instincts, emotions, metamorphosis, photosynthesis, homosexuality, music, language, religion, morality, and altruism (see altruism in animals). Some of these have, in fact, been well-explained by evolution, while others remain largely mysterious, or only have preliminary explanations. However, supporters of evolution contend that no alternative explanation has been able to adequately explain the biological origin of these phenomena either.

In some cases, creationists argue against evolution on the grounds that it can't explain certain non-evolutionary processes, such as abiogenesis, the Big Bang, or the meaning of life. In such instances, evolution is being redefined to refer to the entire history of the universe, and it is argued that if one aspect of the universe is seemingly inexplicable, the entire body of scientific theories must be baseless. At this point, objections leave the arena of evolutionary biology and become general scientific or philosophical disputes.

Objections to evolution's possibility
This class of objections is more radical than the above, claiming that some major aspect of evolution is not merely unscientific or implausible, but rather impossible, because it contradicts some other law of nature or is constrained in such a way that it cannot produce the biological diversity of the world.

Evolution cannot create complex structures


Darwinian evolution posits that all biological systems must have developed incrementally from functional simpler systems. Every stage in the development of, for example, a fin into a leg, must have been sufficiently beneficial to be selected for. Both Darwin and his early detractors recognized the potential problems that could arise for evolutionary theory if the lineage of organs and other biological features could not be accounted for by such gradual, step-by-step changes over successive generations; if all the intermediary stages between an initial organ and the organ it will become are not all improvements upon the original, it will be impossible for the later organ to develop. Anticipating early criticisms that the evolution of the eye and other complex organs seemed impossible, Darwin noted that:

"[R]eason tells me, that if numerous gradations from a perfect and complex eye to one very imperfect and simple, each grade being useful to its possessor, can be shown to exist; if further, the eye does vary ever so slightly, and the variations be inherited, which is certainly the case; and if any variation or modification in the organ be ever useful to an animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, can hardly be considered real."

Similarly, Richard Dawkins said on the topic of the evolution of the feather in an interview for the television program The Atheism Tapes:

There's got to be a series of advantages all the way in the feather. If you can't think of one, then that's your problem not natural selection's problem... It's perfectly possible feathers began as fluffy extensions of reptilian scales to act as insulators... The earliest feathers might have been a different approach to hairiness among reptiles keeping warm.

Despite creationist arguments such as "What use is half an eye?" and "What use is half a wing?", subsequent research has confirmed that the natural evolution of such organs is entirely feasible. Creationist claims have persisted that such complexity evolving without a designer is inconceivable, however, and this objection to evolution has been refined in recent years as the more sophisticated irreducible complexity argument of the intelligent design movement, formulated by biochemist Michael Behe.

Irreducible complexity is the idea that certain biological systems cannot be broken down into their constituent parts and remain functional, and therefore that they could not have evolved naturally from less complex or complete systems. Whereas past arguments of this nature generally relied on macroscopic organs, Behe's primary examples of irreducible complexity has been cellular and biochemical in nature. He has argued that the components of systems such as the blood clotting cascade, the immune system, and the bacterial flagellum are so complex and interdependent that they could not have evolved from simpler systems.

In the recent years since Behe proposed irreducible complexity, new developments and advances in biology, such as an improved understanding of the evolution of flagella, have already undermined many of his arguments. The idea that seemingly irreducibly complex systems cannot evolve has been refuted through a variety of evolutionary mechanisms, such as exaptation (the adaptation of organs for entirely new functions) and the use of "scaffolding", initially necessary features of a system that later degenerate when they are no longer required. Additionally, potential evolutionary pathways have been provided for all of the systems Behe used as examples of irreducible complexity.

Evolution cannot create information
Another new, and increasingly common, objection of creationists to evolution is that evolutionary mechanisms such as mutation cannot generate new information. Creationists such as William A. Dembski, Werner Gitt, and Lee Spetner have attempted to use information theory to dispute evolution. Dembski has argued that life demonstrates specified complexity, and that evolution without an intelligent agent cannot account for the generation of information that would be required to produce specified complexity. The Christian apologetics site Answers in Genesis, for example, makes frequent appeals to concepts from information theory in its objections to evolution and affirmations of the Genesis account of Creation:

"[I]t should be clear that a rigorous application of the science of information is devastating to materialistic philosophy in the guise of evolution, and strongly supportive of Genesis creation."

However, these claims have been widely rejected by the scientific community; new information is regularly generated in evolution, whenever a novel mutation or gene duplication arises. Dramatic examples of entirely new, unique traits arising through mutation have been observed in recent years, such as the evolution of nylon-eating bacteria, which developed new enzymes to efficiently digest a material that never existed before the modern era. In fact, when an organism is considered together with the environment it evolved in, there is no need to account for the creation of information. The information in the genome forms a record of how it was possible to survive in a particular environment. It is not created, but rather gathered from the environment through research – by trial and error, as mutating organisms either reproduce or fail.

A related argument against evolution is that all or most mutations are harmful. However, in reality the vast majority of mutations are neutral, and the minority of mutations which are beneficial or harmful are purely situational; a mutation that is harmful in one environment may be helpful in another.

Evolution violates the second law of thermodynamics
Another objection is that evolution violates the second law of thermodynamics, which states that "the entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium". In other words, an ideal isolated system's entropy (a measure of the dispersal of energy in a physical system so that it is not available to do mechanical work) will tend to increase or stay the same, not decrease. Creationists argue that evolution violates this physical law by requiring a decrease in entropy, or disorder, over time.

However, this claim ignores the fact that this law applies only to isolated systems. Organisms, in contrast, are open systems, as all organisms exchange energy and matter with their environment, and similarly the Earth receives energy from the Sun and emits energy back into space. Simple calculations show that the Sun-Earth-space system does not violate the second law, because the enormous increase in entropy due to the Sun and Earth radiating into space dwarfs the small decrease in entropy caused by the evolution of self-organizing life.

In a published letter to the editor of The Mathematical Intelligencer titled "How anti-evolutionists abuse mathematics", Jason Rosenhouse stated: "The fact is that natural forces routinely lead to decreases in entropy. Water freezes into ice and fertilised eggs turn into babies. Plants use sunlight to convert carbon dioxide and water into sugar and oxygen, but [we do] not invoke divine intervention to explain the process [...] thermodynamics offers nothing to dampen our confidence in Darwinism."

Objections to evolution's morality
Other common objections to evolution allege that evolution leads to objectionable results, including bad beliefs, behaviors, and events. It is argued that the teaching of evolution degrades values, undermines morals, and fosters irreligion or atheism. All of these may be considered appeals to consequences (a form of logical fallacy), as the potential ramifications of belief in evolutionary theory have nothing to do with its objective empirical reality.

Evolution says that humans are animals


As Darwin recognized early on, perhaps the most controversial aspect of evolutionary thought is its applicability to human beings. Specifically, many object to the idea that all diversity in life, including human beings, arose through natural processes without a need for supernatural intervention. Although many religions, such as Catholicism, have reconciled their beliefs with evolution through theistic evolution, creationists argue against evolution on the basis that it contradicts their theistic creation myths.

Some argue that evolutionary common descent "degrades" human beings by placing them on the same level as other animals, in contrast with past views of a great chain of being in which humans are "above" animals.

Evolution leads to immorality and social ills
It is claimed that many perceived social ills like crime, teen pregnancies, homosexuality, abortion, immorality, wars, etc. are caused by a belief in evolution. R. Albert Mohler, Jr., President of Southern Baptist Theological Seminary in Louisville, Kentucky, wrote August 8, 2005 in National Public Radio's forum, "Taking Issue", that "Debates over education, abortion, environmentalism, homosexuality and a host of other issues are really debates about the origin &mdash; and thus the meaning &mdash; of human life.... Evolutionary theory stands at the base of moral relativism and the rejection of traditional morality". Creationist Ken Ham likens evolution to a horde of termites, weakening society's foundation. In Why Won't They Listen?, Ham suggests that "evolutionary termites" are responsible for pornography, homosexual behavior and lawlessness. He also writes, "I'm not saying that evolution is the cause of abortion or school violence. What I'm saying is that the more a culture abandons God's word as the absolute authority, and the more a culture accepts an evolutionary philosophy, then the way people think, and their attitudes, will also change." Former Texas Republican Representative Tom DeLay claimed that the Columbine school shootings were caused by the teaching of evolution. DeLay is quoted as stating that "Our school systems teach the children that they are nothing but glorified apes who are evolutionized [sic] out of some primordial soup." Henry M. Morris, engineering professor and founder of the Creation Research Society and the Institute of Creation Research, claims that evolution was part of a pagan religion that emerged after the Tower of Babel, was part of Plato's and Aristotle's philosophies, and was responsible for everything from war to pornography to the breakup of the nuclear family.

Rev. D. James Kennedy of The Center for Reclaiming America for Christ claims that Darwin was responsible for Adolf Hitler's atrocities. In D. James Kennedy's documentary, and the accompanying pamphlet with the same title, Darwin’s Deadly Legacy, Kennedy states that "To put it simply, no Darwin, no Hitler." In his efforts to expose the "harmful effects that evolution is still having on our nation, our children, and our world." Kennedy also states that, "We have had 150 years of the theory of Darwinian evolution, and what has it brought us? Whether Darwin intended it or not, millions of deaths, the destruction of those deemed inferior, the devaluing of human life, increasing hopelessness." Discovery Institute fellow Richard Weikart has made similar claims, as have many others in the creationist community. Kent Hovind of Creation Science Evangelism blames the Holocaust, World War I, the Vietnam War, World War II, Stalin's war crimes, communism, racism, socialism and Pol Pot's Cambodian killing fields on evolution, as well as the increase in crime, unwed mothers, and other social ills. Kent Hovind's son Eric Hovind has now taken over the family business while his father is in prison, and claims that evolution is responsible for tattoos, body piercing, premarital sex, unwed births, sexually transmitted diseases (STDs), divorce and child abuse.

Supporters of evolution dismiss such criticisms as counterfactual, and some argue that the opposite seems to be the case. There is a published study by author and illustrator Gregory S. Paul demonstrating that religious beliefs, including belief in creationism and disbelief in evolution, are positively correlated with social ills like crime. The Barna Group surveys find that Christians and non-Christians in the US have similar divorce rates, and the highest divorce rates in the US are among Baptists and Pentecostals, both sects which reject evolution and embrace creationism. Michael Shermer argued in Scientific American in October 2006 that evolution supports concepts like family values, avoiding lies, fidelity, moral codes and the rule of law. Shermer also suggests that evolution gives more support to the notion of an omnipotent creator, rather than a tinkerer with limitations based on a human model, the more common image subscribed to by creationists. Careful analyses of the creationist charges that evolution has led to moral relativism and the Holocaust yields the conclusion that these charges appear to be highly suspect. Such analyses has lead many to conclude that the origins of the Holocaust are more likely to be found in historical Christian anti-semitism than in evolution.

Evolution leads to atheism
Another charge leveled at evolutionary theory by creationists is that belief in evolution is either tantamount to atheism, or conducive to atheism. It is commonly claimed that all proponents of evolutionary theory are "materialistic atheists". On the other hand, Davis Young argues that Creation Science itself is harmful to Christianity because its bad science will turn more away than it recruits. Young asks, "Can we seriously expect non-Christians to develop a respect for Christianity if we insist on teaching the brand of science that creationism brings with it?" However, evolution does not either require or rule out the existence of a supernatural being. Robert Pennock makes the comparison that evolution is no more atheistic than plumbing. H. Allen Orr, professor of biology at University of Rochester, notes that,

In addition, a wide range of religions have reconciled a belief in a supernatural being with evolution. Molleen Matsumura of the National Center for Science Education found that "of Americans in the twelve largest Christian denominations, 89.6% belong to churches that support evolution education". These churches include the United Methodist Church, National Baptist Convention USA, Evangelical Lutheran Church in America, Presbyterian Church (USA), National Baptist Convention of America, African Methodist Episcopal Church, the Roman Catholic Church, the Episcopal Church, and others. A poll in the year 2000 done for People for the American Way found that 70% of the American public felt that evolution was compatible with a belief in God. Only 48% of the people polled could choose the correct definition of evolution from a list, however.

One poll reported in the journal showed that among scientists, about 40 percent believe in both evolution and an active deity (theistic evolution). This is similar to the results reported for surveys of the general public. Also, about 40 percent of the scientists polled believe in a God that answers prayers, and believe in immortality. While about 55% of scientists surveyed were atheists or agnostics, atheism is far from universal among scientists who support evolution, or among the general public that supports evolution. Very similar results were reported from a 1997 Gallup survey of the public and scientists.