Becoming upright was one of the first milestones in becoming human. By freeing up our hands, a whole world of tool use, dexterity, and walking became available to us. It may have also allowed our ancestors' brains to grow. What does the fossil record tell us about how bipedalism first evolved?

Once our ancestors gained the ability to walk upright, suddenly, their hands were free. Free to fist fight, carry things, and most importantly, create tools. The ability to manipulate the environment using external objects isn’t entirely unique to our species, but we’ve taken it much, much further than any other creature. And the fossil record shows us that the evolutionary journey our ancestors took to create the first tools is an incredible one - one that paved the way to the tool-filled world we live in today.

Once the hands of our ancestors became free, running became a part of our locomotion. Many animals are fast, but humans are the planet's best long-distance runners. How is this possible for such a strange gangly ape? The answer lies all over our bodies, in tiny pores unique to us - sweat glands.

Today, humans are (probably) the only species with complex language. Did our hominin ancestors have the same ability? Was the evolution of language gradual in our species, or was it a sudden explosion of ability in a short period of time?