Final answer:
The three major body changes that occurred on the way to becoming human include the development of bipedalism, significant brain enlargement, and changes in diet that supported brain growth and development.
Step-by-step explanation:
The question pertains to the three major body changes that occurred in the evolutionary history of humans, leading to the species we know today. Over the course of millions of years, three fundamental developments were critical in the transformation from our ape-like ancestors to modern humans:
- Bipedalism: The shift from moving on four limbs to walking upright on two legs. This change in locomotion allowed our ancestors to cover long distances more efficiently and freed their hands for tool use.
- Brain enlargement: Over time, there was a significant increase in brain size, particularly in the areas associated with memory, thought, and language. This neural expansion facilitated complex social behaviors and the development of sophisticated tools and technologies.
- Changes in diet: The transition to a more varied diet, including the addition of meat, provided the necessary nutrients for the growth of the brain and overall body development. The control of fire for cooking made food easier to digest and unlocked additional caloric value.
These biological changes were accompanied by and contributed to cultural evolution, which in turn accelerated the diversification and capabilities of human societies.