Final answer:
Homo habilis and Homo erectus were hominids that utilized Oldowan tools and had an increased cranial capacity indicative of significant evolutionary development. The use of fire and a dietary emphasis on cooked meat aided brain growth, while reduced jaw size made room for larger brains. The 'woman the gatherer' hypothesis suggests early females played a key role with tools for plant gathering, alongside advancements in blade tool-making during the Upper Paleolithic.
Step-by-step explanation:
Hominids, Oldowan Tools, and Increased Cranial Capacity
The hominids making Oldowan tools and exhibiting increased cranial capacity can be associated with several major developments in human evolution. Homo habilis and Homo rudolfensis were among the early hominids known to create these tools, with Homo habilis having a brain volume of about 800 cc, significantly larger than that of a chimpanzee. Homo erectus, a descendent species, showed an even more pronounced increase in brain size, varying from approximately 550 cc to 1,250 cc, alongside developments such as longer legs for efficient hunting and reduced prognathism, making room for a larger brain.
The use of fire by H. erectus from around 1.7 to 2.0 million years ago marks a pivotal point, as it likely facilitated the cooking of meat and an increase in meat-eating. This dietary change, combined with a colder climate, may have contributed to the brain's growth in volume and complexity. Evidence such as ancient hearths and charcoal suggests that early hominids were not only innovative tool makers, but they also possessed advanced adaptation skills for survival.
The role of early hominid females in the gathering of plant material, as suggested by the "woman the gatherer" hypothesis, points to a nuanced understanding of survival strategies employed by our ancestors. The robust and well-worn molars found in fossil skulls indicate a diet consisting of gritty foods, and the potential use of various organic gathering tools like digging sticks and baby slings, although evidence of these has not survived in the fossil record. The construction of blade tools during the Upper Paleolithic marks a significant advance in tool-making abilities, indicative of increasingly complex cognitive skills.