Final answer:
Homo erectus is the African Homo species considered ancestral to Homo sapiens, whereas Homo habilis is now less widely accepted as a direct ancestor.
Step-by-step explanation:
The African Homo species considered ancestral to Homo sapiens is Homo erectus. This species evolved about 1.9 million years ago in East Africa and is thought to have given rise to Homo heidelbergensis, which in turn is considered to have been among the ancestors of modern humans. Homo habilis, another early species in the genus Homo that lived from 2.5 to 1.4 million years ago, was once thought to be a direct ancestor of Homo sapiens. However, the idea that H. habilis directly led to H. sapiens is no longer as widely accepted. Debates continue within the scientific community regarding the taxonomic position of H. habilis, with some viewing it as a distinct species separate from the direct lineage leading to modern Homo sapiens.