Homo erectus represents a different grade of evolution. what does "grade" mean? having similar adaptive patterns a step towards becoming civilized indicates ancestry to other hominids a bigger and stronger hominid all of the above

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands

c. is the correct answer