Darwinian evolution, also known as the theory of evolution by natural selection, is taught in science textbooks because it is widely supported by a vast body of scientific evidence and is considered the most well-established and well-supported explanation for the diversity of life on Earth. The theory of evolution is based on rigorous scientific research, including extensive observations, experiments, and analyses from various scientific disciplines such as paleontology, genetics, comparative anatomy, and molecular biology.
The theory of evolution explains how species change over time through the processes of variation, selection, and inheritance. It provides a comprehensive framework for understanding the patterns and mechanisms of biological diversity, including the origin of species, adaptation, and the interconnectedness of all living organisms. The theory has been repeatedly tested and has withstood scientific scrutiny for over a century and a half, making it a foundational concept in modern biology.
Alternative theories or ideas, such as humans evolving from aquatic animals or originating from extraterrestrials, have not garnered the same level of scientific support or evidence. While these ideas may be intriguing and have gained attention in popular culture or fringe theories, they lack the robust scientific evidence and consensus required to be considered as established scientific theories. Scientific theories are based on evidence, rigorous testing, and peer-reviewed research, and they undergo scrutiny and revision as new evidence emerges.
Science education aims to provide students with the most accurate and well-supported scientific knowledge available. Therefore, the theory of evolution is included in science textbooks because it is the most widely accepted scientific explanation for the diversity of life on Earth, and it forms the foundation for understanding biology and related fields of study. However, it's important to note that scientific knowledge is dynamic, and as new evidence emerges or new theories gain support, scientific education can adapt and incorporate these advancements.