Evaluate Evidence for Social Behavior Advantages - Biology

1. Which option indicates kin selection rather than reciprocity: helping siblings or helping unrelated strangers once?

   Helping siblings. Helping relatives indicates selection based on genetic relatedness.

2. Identify the best evidence for cooperative hunting advantage: higher capture success in groups or louder calls.

   Higher capture success in groups. Higher success rates demonstrate cooperative hunting effectiveness.

3. Which option is strongest evidence of information sharing: naïve individuals find food faster after joining groups?

   Naïve individuals find food faster after joining groups. Improved foraging success demonstrates information transfer within groups.

4. What is eusociality?

   Reproductive division of labor, cooperative brood care, overlapping generations. Highly organized societies with specialized reproductive roles.

5. What is meant by fitness in evolutionary biology when evaluating social behavior?

   Reproductive success, often measured by surviving offspring produced. Fitness measures evolutionary success through reproductive output.

6. Identify the correct conclusion if group living increases survival but decreases births per adult.

   Net advantage depends on overall lifetime reproductive success. Total lifetime reproductive success determines evolutionary advantage.

7. What is the confusion effect in predator–prey interactions?

   Predators have more difficulty targeting one individual in a group. Groups make it harder for predators to focus on one target.

8. What is mutualism in the context of social behavior?

   A social interaction that increases fitness of all participating individuals. All participants benefit, making cooperation stable and advantageous.

9. Identify the correct interpretation if helpers increase fledgling survival but do not reproduce that season.

   Helping can increase inclusive fitness if beneficiaries are relatives. Helpers gain inclusive fitness through relatives' reproductive success.

10. Which option is the best fitness measure when evaluating social behavior advantages?

    Number of surviving offspring that later reproduce. Reproductive success is the ultimate measure of evolutionary fitness.

11. What is altruism in evolutionary terms?

    A behavior that benefits another individual while costing the actor fitness. Actor pays a cost while recipient gains a benefit.

12. What is the key criterion for calling a behavior cooperative rather than merely social?

    It increases another individual's fitness or survival probability. Cooperation specifically requires helping others, not just social interaction.

13. What is a thermoregulation advantage of social behavior in cold environments?

    Huddling reduces heat loss and lowers energy expenditure. Shared body heat reduces individual energy costs in cold conditions.

14. What is reciprocal altruism?

    Helping that is favored when help is later returned by the recipient. Future reciprocation makes current help evolutionarily beneficial.

15. In Hamilton's rule $rB > C$, what does $r$ represent?

    Coefficient of relatedness between actor and recipient. Higher relatedness makes altruism more likely to evolve.

16. What is meant by cost–benefit analysis of a social behavior?

    Comparing fitness costs to fitness benefits to predict selection outcomes. Determines whether natural selection favors or opposes the behavior.

17. What is cooperative breeding?

    Nonbreeders help raise offspring, increasing offspring survival. Helpers assist parents, improving offspring survival and success.

18. Which type of selection explains altruism toward close relatives?

    Kin selection. Relatives share genes, making helping them evolutionarily beneficial.

19. What is a key condition required for reciprocal altruism to be favored by selection?

    Repeated interactions with ability to recognize and punish cheaters. Recognition and punishment prevent exploitation of helpful individuals.

20. What is the dilution effect in animal groups?

    Individual chance of being attacked decreases as group size increases. Larger groups spread predation risk across more individuals.

21. What is the many-eyes hypothesis for group living?

    More individuals detect predators sooner, increasing group survival. More group members means faster predator detection overall.

22. What is a common line of evidence that social behavior is advantageous?

    Higher survival or reproductive output in social versus solitary individuals. Compares fitness outcomes between social and solitary strategies.

23. What is a common foraging-related advantage of social behavior?

    Increased food-finding efficiency via information sharing. Group members share information about food locations.

24. Identify the best conclusion if group-living animals have higher survival only when predators are present.

    Anti-predator benefits are context-dependent and drive social advantage. Context-dependency shows specific conditions where sociality provides benefits.

25. Which study design most strongly supports a causal advantage of social behavior?

    Controlled experiment manipulating group size or social access. Experiments control variables to establish causal relationships.

26. What is a confounding variable in studies of social behavior advantages?

    A third factor correlated with group living and the measured outcome. Confounds can create false correlations between sociality and outcomes.

27. Identify the most likely cost if larger groups show higher parasite loads but similar food intake.

    Increased disease transmission is a cost of group living. Higher parasite loads indicate disease transmission costs of grouping.

28. What is a key limitation of purely observational evidence for social benefits?

    Correlation does not demonstrate that sociality causes the benefit. Correlation alone cannot establish that sociality causes the benefit.

29. In Hamilton's rule $rB > C$, what does $B$ represent?

    Fitness benefit to the recipient of the altruistic act. Greater benefits make altruistic acts more evolutionarily favorable.

30. Which option best indicates mutualism rather than altruism: both individuals gain or one gains at a cost?

    Both individuals gain. Mutual benefit distinguishes mutualism from one-sided altruism.

31. What is the definition of social behavior in biology?

    Behavior involving interactions among individuals of the same species. Focuses on interactions within a species rather than between species.

32. Which option best supports thermoregulation advantage: lower metabolic rate in huddles or higher parasite rate?

    Lower metabolic rate in huddles. Lower metabolic rates demonstrate energy savings from group thermoregulation.

33. What is an ultimate explanation for social behavior?

    Evolutionary function explaining how behavior increases fitness. Focuses on why the behavior evolved and its fitness benefits.

34. Identify whether $rB > C$ is satisfied if $r=0.5$, $B=10$, and $C=4$.

    Yes, because $0.5\times 10 = 5$ and $5 > 4$. $0.5 \times 10 = 5$, and $5 > 4$ satisfies Hamilton's rule.

35. What is a proximate explanation for social behavior?

    Immediate mechanisms such as hormones, neural circuits, and development. Focuses on how behavior works mechanistically in the individual.

36. What is intraspecific competition?

    Competition among individuals of the same species for limited resources. Same-species competition occurs when resources are limited.

37. What is dominance hierarchy?

    Ranked social order that influences access to resources and mates. Social rank determines priority access to valuable resources.

38. What is cooperative hunting?

    Group hunting that increases capture success or allows larger prey capture. Multiple hunters increase success rate or enable larger prey capture.

39. What does Hamilton's rule state for when altruism can evolve?

    $rB > C$. Altruism evolves when relatedness times benefit exceeds cost.

40. Which conclusion is supported if individuals in larger groups spend less time scanning and more feeding?

    Group vigilance reduces individual vigilance costs, improving foraging time. Shared vigilance allows individuals to allocate more time to feeding.

41. What is inclusive fitness?

    Direct fitness plus fitness gained by helping genetic relatives reproduce. Includes both personal reproduction and benefits from helping relatives.

42. What is a competition-related cost of social behavior?

    Increased competition for food, mates, or nesting sites. Group members compete for the same limited resources.

43. In Hamilton's rule $rB > C$, what does $C$ represent?

    Fitness cost to the individual performing the act. Lower costs make altruistic behaviors more likely to be selected.

44. Which option best supports the many-eyes hypothesis: earlier predator detection or faster growth?

    Earlier predator detection. Earlier detection directly supports the many-eyes vigilance hypothesis.

45. What is a disease-related cost that can reduce advantages of group living?

    Higher pathogen transmission due to close contact and density. Close contact in groups facilitates disease spread between individuals.

46. Identify the confound if healthier individuals both join groups and survive longer.

    Preexisting health status confounds the sociality–survival relationship. Health status affects both group joining and survival outcomes.

47. What is alloparenting?

    Care of offspring by individuals other than the genetic parents. Non-parents provide care, benefiting offspring and sometimes themselves.

48. Which option indicates reciprocal altruism: repeated help between nonrelatives or one-time help to offspring?

    Repeated help between nonrelatives. Repeated exchange between non-relatives indicates reciprocal cooperation.

49. Identify the correct claim if group size increases and per-capita food decreases while survival stays constant.

    Competition costs rise; net advantage is uncertain without reproduction data. Increased competition may offset other benefits of group living.

50. Which option best supports dilution effect: constant attack rate or higher attack rate per individual?

    Constant attack rate (per group) with lower risk per individual. Fixed attack rate with more individuals reduces per-capita risk.

51. Which statement best supports a causal benefit of sociality: random assignment to groups or self-selected groups?

    Random assignment to groups. Random assignment eliminates selection bias and confounding variables.

52. What is a direct advantage of group living related to predation risk?

    Reduced individual predation risk through dilution and vigilance. Group membership decreases individual risk of predator attacks.

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