Evolution & Natural Selection

• evolution


  -genes for characteristics that allow an individual to reproduce are passed on

  - genetic difference between organisms create variation

  - resources are important

  -help them to survive and reproduce
• natural selection


  -environmental pressure select individuals who can survive and reproduce

  - the most useful genes are kept in the population and over time become more frequent

  - the outcome of selection is adaptation- the survivors are better suited to life in the current environment than the predecessors
• sexual selection


  - explains why some characteristics that appear disadvantageous actually confer an advantage bc the characteristics are attractive to potential mates

  - some characteristics are adaptive because they provide an advantage over competitors for reproduction rights
• evolution and aggression


  - guarding your partner - male partner retention

  - offspring guarding - human parents will often direct aggressive behaviour towards other people or animals who threaten their child - increases the offsprings reproductive chances later in life

  therefore, this is the only area where females are more aggressive than males
• strength


  p- evolutionary theory can explain gender difference in aggression

  e- cooperative females are likely to be naturally selected because cooperation protects them and their offspring as a group

  e- in contrast aggressive males are more likely to be naturally selected because they make better hunters

  l- this supports for the explanation for gender differences in aggression and increases the validity of the theory of natural selection
• competing argument


  p- any evolutionary explanation is uncertain because it is impossible to test evolution directs, which is why most research is correlational

  e- because variables are just measured and not manipulated, correlational research can never rule out the effects of other factors on aggressive behaviours.

  l- so this method does not allow us to draw cause and effect conclusion
• weakness


  p- evolutionary theory cannot explain cultural difference

  e- fe, amongs the kung san ppl of kalahari in southern africa, aggression is discouraged from childhood and is therefore rare

  e- in contrast the yanomami of vanezuela and brazil have been described as "the fierce ppl" and aggression is an accepted behaviour to gain status in their sttructural society

  l- therefore, aggression is not universal, which suggests innatley determined behaviour van be outweighted by cultural norm
• strength


  p- buss found in 33 countries that males preferred younger, more attractive and chaste women ( this enhance their reproductive sucess because such women are more likely to be fertile)

  e- females preferred older, wealthier and ambitious or more hard working men ( likely to enhance their reproductive success because their children are well supported)

  l- this support evolutionary theory because it shows that the predictions from the theory are upheld by evidence
• conclusion


  To conclude, the role of the brain in aggression can help us to understand why people with neural injury may commit crimes and have aggressive behaviour. However, the explanation ignores situational factors such as alcohol and drugs, which also lead to aggression.
• What motivates aggression in males, according to evolutionary theory?

  To acquire status
• High status males are more likely to be selected by females because they can guarantee survival
• Low status males may engage in high-risk strategies to enhance their chances of reproduction.
• According to Daly & Wilson's review, what was the primary motive in most murders?

  Status
• Match the status of the individuals with their likely behaviors:

  High status male ↔️ Secures resources and mates

  Low status male ↔️ Engages in high-risk strategies

  Equal status rivals ↔️ Resort to aggression
• Why are females less aggressive than males, according to evolutionary theory?

  Offspring survival
• Females are more likely to use indirect strategies such as gossip and ostracism
• Among the Ache of Paraguay, children are more likely to die if their mother dies, especially at age 1.
• Who published 'The Origin of Species' in 1859?

  Charles Darwin
• Modern humans evolved directly from apes.

  False
• Humans share common ape-like ancestors with chimpanzees and gorillas who lived 6-16 million years ago
• What is the group called that includes humans and apes sharing a common ancestor?

  Hominids
• Natural selection is also known as descent with modification.
• Animals with survival traits are more likely to produce more offspring
• Match the following survival traits with their examples:

  Strength ↔️ Defending from predators

  Cunning ↔️ Outwitting prey

  Teamwork ↔️ Hunting in groups

  Intelligence ↔️ Solving problems
• Why is aggression considered a survival trait?

  To obtain resources
• Genetic mutations always result in positive survival traits.

  False
• A genetic mutation that provides a survival advantage is called a trait
• What is the term for the process by which new species arise from genetic mutations over time?

  Speciation
• All organisms evolve at the same rate.

  False
• What does evolutionary psychology study?

  Behaviors shaped by evolution
• The phrase "Survival of the Fittest" was coined by Herbert Spencer
• What does "fittest" mean in evolutionary terms?

  Most adaptive
• A gene for intelligence might be fitter than a gene for strength.
• Aggression may have evolved as a survival trait to defend against predators
• Which brain structure interprets threats and produces fear or aggression?

  Amygdala
• The pre-frontal cortex allows humans to override aggressive impulses.
• Studying animals to understand human behavior is called ethology
• Match the researchers with their animal studies:

  John Flynn ↔️ Cats

  Higley et al. ↔️ Rhesus monkeys

  Ferrari ↔️ Rats
• What is sexual jealousy in evolutionary terms?

  Protecting one's genes
• Excessive jealousy is considered attractive because it shows strength.

  False