Scientific dogmatism is the assertion of an idea about a scientific topic without proof and without permitting scientists to explore or express alternative ideas.
The best known case of scientific dogmatism occurred in the early 17th century when Italy's established church clung to the Aristotelian notion of all the planets (and the Sun) revolving around the Earth. Copernicus, supported by Galileo (in Italy) and Kepler (outside of Italy) suggested a simpler explanation: that the Earth, along with the other planets, revolve around the Sun. Galileo was censured for making this argument and given the mild but daunting punishment of lifetime house arrest.
In the 19th and 20th centuries, the idea of naturalistic evolution became the modern dogma of biology. Many scientists have found evidence of flaws in the traditional view that undirected mutations alone would add up to important organic differences such as an entirely genus (i.e., group of related species). Yet because of scientific dogmatism, they fear reprisals for publishing this evidence. They could lose positions, tenure, and even employment.  This is a serious risk for scholars who (unlike) Galileo are not independently wealthy.