Evolutionary thought is the idea that life on Earth changes over time. This means that living things adapt to their environment to survive and that the changes eventually become part of their biology. It suggests that life forms are related to each other, like how all people today are related to people in the past who also have a long line of ancestors. This idea goes back thousands of years and was first thought of by scientists and thinkers in Europe, Asia, and Africa. Over the centuries, this idea has grown and changed as people figured out more and more about how living things work and how the world evolves. Scientists now understand a lot more about the process of evolution and it is still an important and growing field of research.