The understanding of how evolution works is a complex and gradual process that took centuries to develop. The concept of evolution and the idea that species change over time can be traced back to ancient Greek philosophers like Anaximander and Empedocles, who proposed early notions of species transformation.
However, it wasn't until the 19th century that the theory of evolution as we know it today began to take shape, largely due to the groundbreaking work of Charles Darwin and Alfred Russel Wallace.
In 1859, Charles Darwin published his seminal work "On the Origin of Species," where he presented his theory of natural selection as the mechanism driving evolution. Darwin's theory proposed that species evolve over time through the process of natural selection, with individuals that possess favorable traits better suited to their environment having a higher chance of surviving and passing on those traits to the next generation.
Alfred Russel Wallace independently arrived at similar ideas about natural selection, and he and Darwin jointly presented their findings to the scientific community.
So, the time it took for humans to figure out how evolution works can be seen as a long process, with key contributions from various individuals over centuries. However, the formalized and comprehensive theory of evolution, as presented by Darwin and Wallace, is one of the most significant milestones in the history of evolutionary understanding.