Final answer:
The presence of a chin did not contribute to the increasing adaptability of Homo erectus, unlike other features such as increased brain size, the use of fire, and dietary changes toward cooked meat.
Step-by-step explanation:
The trait that did NOT contribute to the increasing adaptability of Homo erectus is likely the development of a chin. While Homo erectus evolved a number of adaptations that contributed to their success, such as increased brain size, the use of fire, and changes in diet that included eating cooked meat, these traits developed over time to enhance survival. In contrast, H. floresiensis, which had no chin and different bipedalism characteristics, like thick leg bones and a high stepping gait, suggests that the presence of a chin was not directly linked to adaptability in early hominins.