Michael F. Chapman Jr.
Homo erectus was a well-adapted species capable of much more complicated day-to-day tasks. Much of this ability was due to their morphological changes. These changes occurred in the skeletal system and the soft tissues and were tied to environmental factors, tool use, increased meat consumption as well as the more nomadic lifestyle.
Changes in the skeletal system included a more robust size with a marked increase in size as compared to earlier hominids. This can be seen very well with the Nariokotome boy (WT 15000) where his estimated stature would have been over six feet . The Homo erectus cranial shape also incurred great changes from earlier hominoids. The shape took on a more profound Homo sapien like appearance with a larger more robust size. This is due in part because of the increased brain size, but also because of the larger body size . Resulting from the large size, the cranium of the Homo erectus was the very large brow ridges and the projecting nuchal tarus . The cranium also shows more modern Homo sapien-like teeth unlike earlier species which exhibited larger teeth. Another distinct feature of Homo erectus cranial shape is that of the protruding nose. Unlike the earlier hominoids, this nose protruded from the face much like later hominoids.
The large brain of Homo erectus has led to a number of hypotheses seeking to explain the increase. There is general agreement that the larger brain increased our capacity for the development of more complex behavior and more elaborate tool use. Dean Falk has suggested that the increase in the size of the brain was made possible by a change in the drainage of venous blood from the brain that resulted in more efficient cooling of that organ .