Final answer:
Recent fossil findings in Ileret, Kenya, challenge the linear model of human evolution by indicating that Homo habilis and Homo erectus coexisted rather than having a direct ancestor-descendant relationship.
Step-by-step explanation:
The two recent hominin fossil finds from Ileret, Kenya, are very significant because they show that Homo habilis and Homo erectus overlapped in time rather than being ancestor and descendent. This conclusion is drawn from analyzing the anatomical features, such as brain size, jaw structure, and limb proportions, and comparing these features with other hominins like Australopithecus and Homo species like Homo antecessor. The previous belief that Homo habilis evolved into Homo erectus who then evolved into later human species implies a linear progression, but the evidence from Ileret suggests these species coexisted, potentially interacting with one another. This overlap complicates the understanding of human evolution, signifying that our ancestry is a complex web of different Homo species, not simply a direct lineage from one to another.