Power and Schulkin Chapter 3 Study Guide

chimps

of the great apes, only ___ regularly eat meat

cooperatively

a majority of the time, chimps at most research sites, hunt monkeys _________

meal

when food is brought to a particular place at a particular time and then consumed, usually with other people or a social occasion (formal definition: food served and eaten in one sitting or at a customary time or occasion of eating food)

humans are primates, and we share many features of our biology

trying to reconstruct the dietary environment in which the human metabolic system evolved

• Animal foods are energy-dense. Meat and especially animal fat provide a lot of calories relative to the effort required to obtain them.

• Humans evolved from primate ancestors, so other primates can provide clues about what our ancestors' bodies and diets may have been like.

• Hunting or scavenging animals could produce large, irregular pulses of calories rather than a steady supply of food.

• Under those circumstances, an ability to eat substantially when food was available and store some of that energy as fat could be advantageous.

• That becomes relevant to modern obesity because we now have essentially the opposite environment: energy-dense food is continuously available, while the evolutionary mechanisms promoting energy acquisition and storage remain.

why do they focus on ape meat eating?

• Most primates eat as they go, including if they grab a lizard or dragonfly

• Our ape-cousins specialize in eating fruits and leaves, and sometimes larger animals

• Today humans have expanded their diet to not only eat fruits and leaves, but to regularly include meat in their diet (omnivorous)

• Since humans have neither the strength nor speed to catch our own creatures for food, humans have relied on our large brain to develop and use tools to help us catch and butcher animals

Power-Schulkin argument

meat-sharing

a unique practice among chimps when an individual catches a money (or bird)

Chimpanzees are more likely to share meat when it is a rare, highly valued resource obtained through hunting, particularly when sharing can strengthen social relationships, gain social support, or promote future cooperation. Thus, meat sharing may function less as simple generosity and more as a form of social exchange.

some of the conditions when chimpanzees might share meat?

the importance of cooperation is that it may have been a major force shaping human evolution—especially our ability to obtain food that an individual could not easily obtain alone.

The Melis et al. work showed that chimpanzees can cooperate when cooperation is actually necessary, but their success depends heavily on social tolerance. Chimpanzees that were more willing to share food were better able to work together to obtain food.

Department of Evolutionary Anthropology+1Why would cooperation matter evolutionarily?

• Access to larger, high-energy foods: Cooperation could allow several individuals to obtain resources that would be difficult or dangerous for one individual to acquire.

• Hunting and scavenging: This is particularly important for the human evolutionary story. A group could cooperate to hunt animals or defend a carcass from competing predators. Scavenging a large carcass, for example, could require multiple individuals working together. R

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• Food sharing: Once individuals cooperate to acquire food, they need some degree of tolerance and sharing. This could favor increasingly egalitarian social relationships.

• Greater energy availability: Cooperative food acquisition could increase access to calorie-dense foods, potentially supporting the energetically expensive human brain and other costly biological traits.

• Social evolution: Cooperation creates pressure for individuals to recognize trustworthy or effective partners. Interestingly, another 2006 Melis study found that chimpanzees could recognize when cooperation was necessary and select a more effective partner.

the importance of cooperation

The important finding is that sharing can depend on the social situation. In one version of the game, where the recipient could accept or reject the proposed division, chimpanzees chose an equal split more often than a selfish split. But when the other chimp had no influence over the outcome (similar to a dictator game), they tended to choose the selfish option.

This suggests that chimpanzees may share food when cooperation or the partner's response matters. In other words, sharing isn't necessarily an automatic concern for fairness; it can be a strategy for maintaining cooperation and avoiding conflict.

Fairness for chimps appears to be mainly transactional; sharing for gain. Sharing is not the default condition.

what did the Ultimatum Game indicate about some conditions when chimps or bonobos might share food? were chimps fair sharers?

The basic idea is:

kill/find carcass → transport valuable parts → bring them to a safe central place → process and eat together → share food and strengthen social relationships.

This is significant for Power and Schulkin because it connects meat acquisition with cooperation and food sharing, which could have helped shape the social and energetic aspects of human evolution.

the proposed advantages for brining a carcass to a central place to eat it

The disadvantages of transporting a carcass included the energy and time required to carry it, the difficulty of moving a heavy carcass, and increased exposure to predators or competing animals that might steal the food.

what are some disadvantages of traveling with a carcass

Humans would have needed advanced social cognition—including the ability to recognize others' intentions, cooperate, tolerate others around valuable food, remember social relationships, and share food fairly. These abilities would allow communal eating to work rather than turning into constant competition over the food.

mental properties needed to develop that would seem critical for a group to sit around together and eat communally, possibly sharing with each other

A group of highly aggressive, food-competitive animals would have difficulty eating communally. For communal meals to evolve, there must have been increasing tolerance, cooperation, food sharing, and social mechanisms that suppressed aggression around valuable food.

if they are typically aggressive and competitive with each other for food, could that group eat a meal togetherggressive behavior can hinder communal eating.

“Patience is a virtue” relates to the evolution of meals because communal eating required individuals to control their immediate desire to compete for food. The ability to wait, tolerate others, share, and delay gratification would have reduced aggression and allowed cooperation and social bonding around food to develop.

how does the phrase, “patience is a virtue”, relate to the story of the evolution of meals

meat sharing

has social/political meaning and consequences; for the spoils of the hunt