Lyell helped Darwin realize that the earth has been around way longer than initially believed. This was how macro evolution possibly was able to take place, over the millions of years of species walking the earth. Darwin pulled that evolution happens because of natural selection. We human's have the traits we have today because we have been able to develop traits to adapt to our environment. As the world goes on and changes, species need to change too by having traits beneficial to their surroundings. This happens by the weaker species getting killed off by things like famine and disease and the better traited species become more common amongst generations. That's why as you can see in our diagram that us humans have evolved greatly, we believe. Scientists have discovered thousands of human fossils that enable them to research the changes that consist in the brain, body size, and overall features. "Millions of stone tools, figurines and paintings, footprints, and other traces of human behavior in the prehistoric record tell about where and how early humans lived and when certain technological innovations were invented.