In Britain, while publication of The Descent of Man by Darwin in 1871 reinvigorated debate from the previous decade, Sir Henry Chadwick notes a steady acceptance of evolution "among more educated Christians" between 18.As a result, evolutionary theory was "both permissible and respectable" by 1876.Evolution was at first opposed among the scientific community, notably by Georges Cuvier, and religious grounds.
Regardless of acceptance from major religious hierarchies, early religious objections to Darwin's theory are still used in opposition to evolution.
The ideas that species change over time through natural processes and that different species share common ancestors seemed to contradict the Genesis account of Creation.
Since then creationists have developed more nuanced objections to evolution, alleging variously that it is unscientific, infringes on creationists' religious freedoms, or that the acceptance of evolution is a religious stance.
One of the main sources of confusion and ambiguity in the creation–evolution debate is the definition of evolution itself.
Although early objectors dismissed evolution as contradicting their interpretation of the Bible, this argument was legally invalidated when the Supreme Court ruled in Epperson v.
Arkansas in 1968 that forbidding the teaching of evolution on religious grounds violated the Establishment Clause.
However, in the 1920s Christian fundamentalists in the United States developed their literalist arguments against modernist theology into opposition to the teaching of evolution, with fears that Darwinism had led to German militarism and was a threat to religion and morality.
This opposition developed into the creation–evolution controversy involving Christian literalists in the United States objecting to the teaching of evolution in public schools.
The observation of evolutionary processes occurring (as well as the modern evolutionary synthesis explaining that evidence) has been uncontroversial among mainstream biologists since the 1940s.