<human>:  Who was the first person to propose that humans evolved from a common ancestor?
<bot>: The theory of evolution was first proposed by Charles Darwin in 1859. In his book On the Origin of Species, Darwin explained how life on Earth had changed over time through a process called natural selection. Darwin’s theory of evolution was controversial at the time, and many scientists were skeptical of it. However, since then, there has been a huge amount of evidence supporting Darwin’s theory.