History of evolution?
Evolution is usually defined as "change over time." In spite of the incredible diversity of life found on Earth, many fundamental characteristics are shared by living organisms. While the differences can be astounding, careful study has turned up compelling similarities that consistently appear among the different life forms.
Prior to Darwin's publication of On the Origin of Species, biological thinking pretty much reflected Aristotle's and Plato's 2000-year-old teachings that life forms never changed and that humans represented the highest rung on the ladder of life. Judeo-Christian theology supported these ideas by teaching that God created humans in his own image.
Jean Baptiste Lamarck suggested an alternative, the Theory of Acquired Characteristics. Although his theory was not widely accepted, at the time his ideas were fresh, and served to stimulate the intellect.
In 1858, Charles Darwin developed the concept that life forms on Earth have changed over the years, thereby ushering in a new age of biology. The concept that individual species derive from common ancestors has now gained widespread acceptance among scientists.