Expensive-Tissue Hypothesis

It has recently been suggest that there is no evolutionary trade-off between the brain and the gut, or another expensive organ in hominins (Navarrete et al. 2011: 91-93). Instead encephalization is made possible by the stabilization of energy inputs and the redirection of energy from locomotion, growth and reproduction (ibid.). Larger brains are the result of a shift to eating cooked meat and underground tubers which gradually decreased the size of the digestive track (ibid.). Additionally, the expensive-tissue hypothesis lacks empirical support and nor has it never been fully proved or experimented on (ibid.). Nonetheless, this rebuttal also currently lacks evidence, namely morphological data (ibid.).

Adaptive change, with the use of the

Despite this reduction the in size the function of the visual region has greatly improved, for instance, the evolution of parvocellular vision (ibid.). In general, hominin eyes and orbits rotate in a forward direction, which has been argued to aid grasping and predation (ibid.; Martin 2012: R785-R790). This is the argument for the ‘Binocular Summation’ hypothesis proposed by Barton (2004: 10113-10115), which suggests that enhancement of the visual cortex guides hunting. Improved close-range handling would also allow for technological advancements, such as tool use

The use of tools to obtain resources from the surrounding environment and exploit new niches requires a high level of cognitive ability (Stanford et al. 2013). One must be flexible in methods of extraction and foraging pattern especially in times of scarcity when resources are more difficult acquire (ibid.; Wynn 1988: 271-284), for instance crushing the shells of nuts to gain food rather than peeling fruit. Moreover, this ‘Tool Making’ hypotheses demands considerable foresight when making tools, for it requires a mental image of what one want to create (ibid.). These skills must be passed on to the next generation in a cultural transmission of behaviour (information exchange) (ibid.). In order to efficiently exploit the environment, it has been inferred that young hominins observed and imitated their peers in order to learn these complex behaviours, which also include language and hunting (Stanford et al. 2013; Wynn 1988: