Terry: "H. ergaster and H. erectus are almost certainly just opposite ends of a cline that stretched from Southeast Asia, through China and the Middle East into Africa. Ergaster in Africa, erectus in SE Asia with other regions somewhere between."

The Smithsonian chart (link below) shows H. erectus as having evolved from H. ergaster, apparently with no evidence of H. ergaster since well over a million years ago. Do you disagree with that?

http://www.mnh.si.edu/anthro/humanorigins/ha/a_tree.html

"Time is what prevents everything from happening at once" - John Wheeler