Evolution of human behaviour Flashcards
(65 cards)
What is mosaic brain evolution?
Mosaic brain evolution refers to the concept that different parts of the brain evolve at different rates. This means that various brain areas can expand or shrink independently, leading to specialized cognitive abilities in different species.
For example, in primates, the cerebellum has evolved rapidly in humans compared to other brain regions, suggesting distinct evolutionary pressures on motor control and cognitive processing.
What are the main hypotheses explaining the evolution of cooperation in humans?
The main hypotheses for the evolution of cooperation in humans include: 1) Kin Selection – cooperating with close relatives to increase shared genetic fitness. 2) Reciprocal Altruism – cooperating with non-kin with the expectation of future reciprocation. 3) Group Selection – cooperation evolves for the benefit of the group. 4) Cultural Group Selection – large-scale cooperation shaped by cultural practices.
What is kin selection, and how does it explain cooperation?
Kin selection, as proposed by Hamilton, explains that individuals are more likely to cooperate with relatives because they share common genes. This increases the likelihood that those genes will be passed on to future generations.
An example is alarm calling in ground squirrels, where individuals risk their lives to warn close kin of predators.
What is reciprocal altruism, and how does it work?
Reciprocal altruism is the idea that individuals cooperate with others, even non-relatives, with the expectation that the favor will be returned in the future.
This is often seen in the vampire bat’s food-sharing behavior, where bats that have received food help starving bats in return.
What is the social brain hypothesis?
The social brain hypothesis posits that larger brains, particularly the neocortex, evolved in primates to manage increasingly complex social relationships.
How does ecological theory explain brain size evolution in primates?
Ecological theory suggests that primates evolved larger brains to cope with complex ecological challenges such as foraging, using tools, and navigating varied environments.
What are the challenges in measuring brain size and cognitive abilities?
Measuring brain size alone is a poor indicator of intelligence. Brain structure, organization, and neuron density are more important. Cognitive abilities are difficult to compare across species due to the vast differences in brain functions and environments.
What is the relationship between brain size and body size in primates?
Brain size in mammals, including primates, is largely determined by body size. Larger animals tend to have larger brains, but humans have disproportionately large brains relative to body size, which is thought to be an adaptation for complex cognition and cultural behaviors.
How does the evolution of large brains impact energy consumption?
The evolution of large brains comes at a high metabolic cost, consuming about 20% of the body’s energy despite representing only 2% of body mass. Larger brains also extend developmental periods, requiring longer gestation and juvenile stages.
What is the evidence supporting the ecological hypothesis for brain size evolution?
Ecological hypotheses argue that brain size evolved in response to complex environments, such as the need for flexible foraging strategies, navigating large home ranges, and extractive foraging.
What is the cultural group selection hypothesis in human cooperation?
Cultural group selection suggests that cooperation evolved due to competition between groups. Groups with more cooperative members were more successful, leading to the spread of cooperative behaviors, particularly in large-scale human societies.
What is the puzzle of altruism in evolution?
Altruism, where individuals behave in ways that benefit others at a personal cost, is a puzzle in evolutionary biology. The puzzle arises because natural selection should favor behaviors that increase an individual’s own fitness, not reduce it.
What is the gene’s eye view of evolution?
The gene’s eye view, popularized by Richard Dawkins, suggests that evolution occurs at the level of genes, which compete for replication. Behaviors that increase gene survival, even at a cost to the individual, can evolve if they increase the reproductive success of related individuals.
What is the relationship between cooperation and reciprocity in human evolution?
Reciprocal altruism, a form of cooperation where individuals help others with the expectation of future help, is fundamental to human evolution.
How does sexual selection differ from natural selection?
Sexual selection, a subset of natural selection, focuses on traits that increase an individual’s chances of reproducing, such as mate competition and mate choice.
How does Bateman’s principle explain sexual selection in mammals?
Bateman’s principle suggests that males have greater variation in reproductive success than females because males can increase their reproductive success by mating with multiple females, whereas females are more limited in reproductive opportunities.
What is parental investment in the context of sexual selection?
Parental investment refers to the time, energy, and resources invested by parents in raising offspring. In mammals, females generally invest more in reproduction (e.g., gestation, lactation), while males may invest less but compete for access to females.
What is the significance of sexual dimorphism in primates?
Sexual dimorphism refers to differences between males and females in traits like size, color, and ornamentation. In primates, sexual dimorphism often correlates with mating systems, such as polygyny, where males are larger to compete for mates.
How do human mating systems differ from those of other mammals?
Human mating systems are more flexible and culturally influenced. While polygyny is common in many mammals, humans exhibit a mix of monogamy, polygyny, and other systems, with cultural factors playing a significant role in mate choice and partnership dynamics.
How does evolutionary theory explain mate preferences in humans?
Evolutionary theory suggests that mate preferences are shaped by reproductive strategies. Women tend to prefer partners with resources or long-term stability (due to higher reproductive investment), while men prefer youth and fertility, which signal reproductive potential.
What is the evidence for the evolution of mate preferences?
Studies show that women tend to prefer men with resources or status, while men prefer women with physical traits indicating fertility, such as youth and symmetry.
What is sperm competition, and how does it relate to human evolution?
Sperm competition refers to the competition between sperm from different males to fertilize the same female’s eggs. In humans, sperm competition is moderate, and the size of male testes is indicative of this competition in species with multi-male mating systems.
What is the role of ovulation in human mating systems?
Unlike many mammals, human females do not exhibit clear external signs of ovulation. However, subtle cues may affect mate preferences, and studies suggest that women’s facial attractiveness increases during their fertile phase.
What is the ‘tragedy of the commons’ in relation to human cooperation?
The ‘tragedy of the commons’ occurs when individuals exploit a shared resource for personal gain, leading to its depletion. Cooperation is essential to avoid this, and human evolution has seen the development of cultural mechanisms to encourage cooperation and prevent exploitation.
