When did Darwin propose the theory of evolution?

After systematically expounding the principle of natural selection, Darwin was not in a hurry to express his thoughts. He realized that his research would inevitably lead to strong opposition, so he took this view as a hypothesis and spent 20 years collecting facts and conducting experiments. He read a lot of books, travel diaries and books about sports competitions, natural history, gardening and livestock raising. He carried out the experiment of pigeon mating and studied the spread of seeds and the geographical distribution of animals and plants. ?

Darwin wrote the outline of his theory as early as 1842, and he began to write books in 1844. But in June 1858 and 18, when Darwin was still supplementing and revising his great works, he received a paper from alfred russel wallace (a British naturalist) from Turner, east indies. Wallace finished this paper in three days after reading Malthus' book. Darwin immediately saw that this paper contained his own theoretical views. Wallace gave the manuscript to Darwin in order to get the opinions and comments of a famous scientist before publication. This is embarrassing and may cause unpleasant priority disputes. Darwin gave up the priority of these 20 years. In July 1858, 1, Wallace's paper and Darwin's outline were submitted to a scientific group as * * * papers. ?

Unexpectedly, the submission of this paper did not attract much attention. However, Darwin's On the Origin of Species published the following year caused a strong response. In fact, there may not be a scientific work that has caused such a wide and heated discussion inside and outside the scientific community as the Origin of Species by Natural Selection, that is, Survival of the fittest by Natural Selection (referred to as the Origin of Species for short). This debate was still going on in 187 1 when Darwin published "Grey and Sexual Selection of Human Beings". The book puts forward the view that human beings evolved from apes and other animals, adding a spoonful of oil to the heated debate.