No one has contributed more to the understanding of the evolution of the human species than Charles Darwin, whose theory of evolution overturned the norms of the Victorian era, completely changed our perceptions of life on Earth, and continues to be attacked today by followers of all religions. In this edition, the chapters on Natural Selection from The Origin of Species are published, which is one of the most important books of all time. Utilizing a wealth of evidence, Darwin defends the idea (which others before him had also supported) that species evolve, additionally discovering a mechanism that makes such evolution possible. He argues that life is like a tree where, as its roots grow, different branches, the species, form, which, over time, continue to differentiate, leading to the creation of new species always under the influence of certain limiting factors. "In the century and a half that separates us from the publication of The Origin of Species, the theory developed in the book has been fully confirmed. Some questions may remain to be clarified, but Darwin's theory of evolution provides us with an essential conceptual and interpretative framework for understanding the natural world in a rational way, without resorting to myths." El País