Evolution is the change in allele frequency over time as well as the scientific theory which describes it. This accounts for the diversity of life on earth, starting from a common ancestor by the processes of evolution driven by natural selection. The theory was proposed in Charles Darwin's book The Origin of Species and since developed to include genetics and many other scientific discoveries.
Evolution is often linked to atheism because it is perceived to be a threat to biblical literalism and young earth creationism. However, many religions and churches accept or at least tolerate evolutionary theory. 
Evidence for Evolution
An in-depth study on the subject of evolution is beyond the scope of this wiki. Only those arguments that relate directly to atheism and the existence of God should be cited in articles. For more information, please visit any or all of the following:
- TalkOrigins website, which provides in depth explanations of apologetics relating to evolution.
- Evolution Wiki
- "Evidence of Common Descent" at Wikipedia
- "List of Transitional Fossils" at Wikipedia
- "Human Evolution" at Wikipedia
Acceptance of evolution varies between religions and denominations.
"some new findings lead us toward the recognition of evolution as more than an hypothesis"
While generally accepted by Christians, evangelical protestant Christians in the US generally reject evolution, with 64% of whites and 50% of blacks believing humans were created by God in their present form. Catholics and mainstream protestants in the US generally accept evolution as true. A minority of Christian believers accept the notion of theistic evolution, in which God directs evolutionary processes. 
Common Misconceptions about Evolution
There are some very common and persistent misconceptions about the basics of evolution itself:
- Evolution only concerns itself with the diversification of living species. It does not address other topics such as the origin of life itself, the Big Bang, the formation of planet Earth, and so on. These are each covered by different scientific fields of study, such as abiogenesis, cosmology, and physics. Creationists often misuse the term "evolution" to erroneously refer to pretty much any science that contradicts a literal interpretation of the Book of Genesis (see the Jack Chick tract 'Big Daddy' for an example).
- Evolution is both an established fact and a scientific theory. In science, a theory is not the same thing as a hypothesis. Those who try to dismiss evolution with the claim that it is "just a theory", are ignorant of the meaning of the word "theory" as it's used in science.
- Micro-evolution and macro-evolution are not distinct processes.   Small changes can accumulate over long periods and results in large changes.
- Evolution does not predict that speciation will result in a completely different kind of animal.  Evolution predicts mammals remain mammals and primates remain primates, etc. Generally, evolution does not allow for two different species to interbreed (i.e. a Crocoduck cannot occur).
- Fossils that exist between two lineages, so called "transitional fossils", exist.
There are many other objections made against evolution but these are addressed in the resources cited below. The TalkOrigins archive is an excellent and comprehensive resource regarding objections to evolution. 
Religious Objections to Evolution
- The grouping of life specified in the bible is called a "kind" and has fixed boundaries. This is not consistent with the current scientific consensus on the common descent of life. The Bible does not define the boundary of a kind.  The study of kinds, as described in the Bible, is known as Baraminology and is a form of pseudoscience.
- There is insufficient time for evolution to take place if young earth creationism is true. Youth Earth creationism considers the Earth to be less than 10,000 years old. Evolution would require a longer time period to evolve complex life from the common ancestor: probably hundreds of millions to billions of years.
- Humans are descended from other animals. If animals do not have souls, at what stage did human ancestors acquire a soul? The idea of common descent is therefore objectionable.
However, being an atheist is not a requirement for understanding and accepting evolution. There are plenty of theists who see no personal religious conflict in accepting evolution and believing in a deity.  Evolution is a biological science and does not say anything about deities, one way or another. Likewise, not believing in a deity does not automatically mean that one accepts evolution; for example there are non-theistic groups such as the Raëlians who deny evolution.
Theistic evolution is a group of beliefs relating to the compatibility of religion and evolution. They range from God creating the laws of nature with the knowledge that they would result in humans to the belief that God directly influenced the mutations that occurred to produce humans. Many religions accept evolution but consider abiogenesis to have a supernatural cause.
While claiming compatibility with science, theistic evolution is not required for the evolutionary process to occur and does not provide any additional explanatory power. Therefore the theistic evolution hypothesis can be discarded by Occam's razor.
Evolutionary processes are wasteful and unnecessary
- Main Article: Argument from poor design
Evolution is full of failed attempts, suffering of living things and the extinction of most historic species. An omnipotent designer would not use such cruel means to create humans.
Past events are not testable
- "The past is not directly observable, testable, repeatable, or falsifiable; so interpretations of past events present greater challenges than interpretations involving operational science. Neither creation nor evolution is directly observable, testable, repeatable, or falsifiable. "
Evolution has been seen to occurred even on relatively short time scales. Evolution also makes falsifiable predictions about what we should expect to find in the fossil record.
Academic support for evolution is a conspiracy
According to some apologists, academics support evolution so that they can pretend to be the "highest authority when it comes to truth", their commitment to naturalism, they would "would risk losing financial security and professional admiration" and just want to carry on sinning. 
This misrepresents academics in numerous ways and is a straw man. Academics generally follow the evidence but, unlike apologists, do not employ the argument from ignorance. It also overlooks that any academic that published a credible disproof of evolution, they would be world famous, probably win a Nobel prize and become a scientific hero. Of course, intelligent design and specified complexity are not scientifically credible.
After citing the example of Adolf Hitler and others, apologists conclude:
- "In other words, racism and then genocide is the logical outworking of Darwinism.[...] As horrific as that would be—using retarded people as lab rats or for food—Darwinists can give no moral reason why we ought not use any human being in that fashion."
Hitler made some claims about the struggle for life and racial theory, particularly in terms of prescriptive policies, but these are not part of evolutionary theory, which is strictly descriptive. Those would claim that social policies should be justified by evolution forget the is-ought problem, which says prescriptive claims cannot be based entirely on descriptive propositions. Just as Darwinism does not forbid misusing people, it does not encourage either. Adolph Hitler required additional moral judgements, such those he took from Norse mythology and Christianity, to justify his actions.
Almost all scientists accept evolution but virtually none accept social Darwinism. This shows that it does not necessarily lead to social Darwinism.
So called "Social Darwinism" originates before Darwin published his ideas! It goes back to at least Herbert Spencer's 1851 Social Statics and 1852 A Theory of Population. The Origin of Species was published in 1859. Spencer originally considered species to originate through Lamarckism, not natural selection.
"“A generous poor-law” is openly advocated as the best means of pacifying an irritated people. Workhouses are used to mitigate the more acute symptoms of social unhealthiness. Parish pay is hush-money. Whoever, then, desires the radical cure of national maladies, but especially of this atrophy of one class, and hypertrophy of another, consequent upon unjust land tenure, cannot consistently advocate any kind of compromise."
- — Social Statics, 1851 
"For, necessarily, families and races whom this increasing difficulty of getting a living which excess of fertility entails, does not stimulate to improvements in production—that is, to greater mental activity—are on the high road to extinction; and must ultimately be supplanted by those whom the pressure does so stimulate."
- — A Theory of Population, 1852
Religion as an evolutionary phenomenon
Religious practice involves some effort or cost and these costs are rarely recovered directly. This includes a significant amount of resources, time, intellectual capacity and lost opportunities. Evolutionary theory predicts that detrimental traits, such as religious tenancies incurring a cost, would become progressively less common in later generations due to natural selection unless they are counter-balanced by some evolutionary benefit. This implies that religion should have some evolutionary advantage. The exact mechanism for religion to occur has not been conclusively determined and research is ongoing.
One idea is that religious belief is an evolutionary accident, in which human cognitive faculties have developed and religion is an incidental side effect of the functioning of our brains. The imperfect nature of our cognition manifests itself in many ways, including an agent detection bias and an unjustified belief in dualism.
- ↑ 1.0 1.1 Acceptance of evolution by religious groups, Wikipedia 
- ↑ 
- ↑ 
- ↑ John D. Morris, "What Is The Difference Between Macroevolution And Microevolution?" 1996, Acts & Facts. 25 (10). 
- ↑ Douglas Futuyma, "Evolutionary Biology" (1998), pp.477-8
- ↑ Watch Tower Society, "Was Life Created?", p. 20
- ↑ Index to Creationist Claims, TalkOrigins archive
- ↑ Watch Tower Society, "Was Life Created?", p. 28
- ↑ 
- ↑ 10.0 10.1 I Don't Have Enough Faith to be an Atheist
- ↑ 
- ↑ 
- Warren Kurt VonRoeschlaub, God and Evolution, TalkOrigins archive.