How might Homo ergaster be related to later Homo species?

Many paleoanthropologists consider Homo ergaster—often identified as the African representative of Homo erectus—to be a probable ancestral form for later Homo species, including modern humans.12

While some researchers argue that the specialized, robust features of Asian H. erectus make it an unlikely direct ancestor to Homo sapiens, H. ergaster is viewed as a more suitable candidate. This species is thought to have evolved in the direction of modern humans, potentially through an intermediate step such as Homo heidelbergensis.123

Although the exact path of human evolution remains a subject of significant debate, studies of body size in human evolution suggest that representatives of the genus Homo can be organized into a sequence showing gradual increases in size, a trajectory in which H. ergaster fits well. Ultimately, while the fossil record provides evidence of these transitions, there is no firm consensus on whether the emergence of Homo sapiens occurred through gradual change or more rapid evolutionary scenarios involving migration.1