Final answer:
Homo erectus in the early Pleistocene had characteristics such as similar height to modern humans, use of sophisticated tools and fire, cooperative hunting and foraging, vocal communication capacity, and caring for the sick and elderly.
Step-by-step explanation:
Homo erectus, an early species in the genus Homo, had several key characteristics during the early Pleistocene. They were similar in height to modern humans, made sophisticated stone tools, and used fire for warmth and cooking. They likely lived in constructed huts and hunted and foraged cooperatively. Additionally, Homo erectus exhibited some vocal communication capacity and showed evidence of caring for the sick and elderly. These characteristics made them highly adaptable to changing climates and environments.