Final answer:
The diet of Homo erectus included significantly more meat compared to that of earlier hominins, due to increased brain size and caloric needs. Use of fire to cook meat led to anatomical changes and facilitated hunting capabilities.
Step-by-step explanation:
The diet of Homo erectus contained more meat and high-quality foods than the diets of previous hominins. The increase in brain size of H. erectus, ranging from about 550 cc to 1,250 cc, necessitated greater caloric intake. Evidence shows increased use of fire and consumption of cooked meat, which would have required a 35 percent larger caloric intake than their ancestors. This dietary shift towards more meat consumption is supported by anatomical changes such as reduction in tooth and jaw size and a decrease in prognathism as softer, cooked foods required less chewing strength.
Further evidence of meat eating comes from the KNM ER 1808 specimen, dated about 1.7 million years ago, indicating H. ergaster may have consumed carnivore liver, high in Vitamin A. The adoption of efficient bipedal movement allowed H. erectus to hunt and scavenge over greater distances, thus increasing access to animal proteins. Cold climate adaptations also suggest a reliance on cooked meat, contributing to advancements in cognitive abilities and the development of sophisticated tools for hunting.
While regional diets varied, the general trend towards a higher proportion of animal-based foods, compared to primarily plant-based diets of earlier hominins, marks a significant change in hominin diet during the times of Homo erectus.