In the 250,000 that humans have wandered the Earth, our brains have remained the same. What has changed is the storehouse of built-up knowledge and experience which, in humans, is handed down orally, and in the last ten thousand years or so, in written form. This makes it seem like our brains have evolved to become smarter, whereas early man must have been much dumber. This is an insult to our early ancestors. They too used their big brains to at first eke out an existence and then to prosper and even thrive, eventually overrunning the entire planet. Humans now live on each of the 7 continents. Yes, even in Antarctica there exists a permanent scientific base with anywhere from 20-150 scientists living there year-round.
It is our capacity for adaptation which is evident in our humanity.
Early humans had to adapt as well. According to the latest genetic evidence, modern Homo Sapiens stayed in Africa about 3/4 of our existence as a species, only venturing out of Africa some 50,000 years ago. Those that left had to adapt to new environments and challenges, but the ones that stayed also had to change. Africa was just as affected by the birth and death of successive ice ages. This drove the climate into a see-saw effect.
Humans are the premier tool-makers of the natural world. We make tools. We make tools to make other tools. We even make tools to make other tools with which to make yet more tools. We take it up exponentially. Recently, in Africa, giant stone hand-axes were discovered in a dry lake bed. These are some of the largest ancient hand tools ever uncovered. Were they used to butcher massive carcasses? Were they used to fell trees or saplings? These monster tools are an amazing sign of the ingenuity of early man. -FUPPETS- thinks they kick ass.