homo vs Homo erectus

homo and Homo erectus both are nouns.

Word	Noun	Adjective	Verb	Adverb
homo	Yes	No	No	No
Homo erectus	Yes	No	No	No

As nouns, Homo erectus is a hyponym of homo; that is, Homo erectus is a word with a more specific, narrower meaning than homo:

homo: any living or extinct member of the family Hominidae characterized by superior intelligence, articulate speech, and erect carriage
Homo erectus: extinct species of primitive hominid with upright stature but small brain

homo (noun)	Homo erectus (noun)
any living or extinct member of the family Hominidae characterized by superior intelligence, articulate speech, and erect carriage	extinct species of primitive hominid with upright stature but small brain
someone who is sexually attracted to persons of the same sex