• Emergence of early hominins from wetland forests to bipedal open grassland inhabitants led to food sources not previously available, namely the availability of large grazing animals. (Mann, 2007)
• A higher quality diet shortened the duration of suckling and lactation during early hominin development, allowing an increase in reproduction rates and a decrease in the time needed between births. (Psouni, Janke & Garwicz, 2012)
2. Anatomical evidence for hominin meat-eating
• Early hominin fossil remains show decrease in molar size and a more gracile structure of the jaw, suggesting less grinding in the diet and more biting and tearing. (Mann,2007)
• Comparison of the gut in humans and apes; colon takes up 45% of gut volume in apes while small intestine takes up 56% of gut volume in humans. (Milton, 2003) …show more content…
Why eat meat in the first place?
• Pre-agricultural humans relied on meat to provide important nutrients essential to health such as protein, amino acids, vitamins and minerals. (Mann, 2013)
• Consuming meat regularly would have permitted evolving hominins to bypass the nutritional constraints placed on body size increases found in herbivorous apes. (Milton, 2003)
• Humans have a weak ability to produce taurine, an important amino acid that has several important biological functions like acting as an antioxidant and anti-inflammatory: must be supplemented through diet and found almost exclusively in animal products. (Pereira & Vicente, 2013)
• Young children, with their fast expanding brain and high nutritional demands in comparison to adults would have benefitted from consuming nutrient rich foods such as meat. (Milton, 2003)
4. The expensive-tissue hypothesis
• Brain is very expensive in terms on metabolic activity; Aiello & Wheeler (1995) suggest that the cost of increased encephalization must have been offset by the reduction of other metabolically expensive organs, namely the digestive