Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
Imagine a population of birds in which first-year birds can either find a mate and raise an average of three offspring or stay in their parents' territory and help the parents raise two more offspring than the parents would have been able to raise without any help. Based on the theory of kin selection, we would expect that __________.
A
most territories would have young birds helping at the nest
B
altruistic behavior would be common in this population
C
most first-year birds would choose to forgo breeding
D
nutrient cycles would be disrupted
E
the behavior of helping at the nest would not evolve in this population
Verified step by step guidance
1
Understand the concept of kin selection: Kin selection is a form of natural selection where individuals can increase their own genetic success through altruistic behavior that benefits relatives. The key idea is that helping relatives can indirectly pass on shared genes.
Calculate the inclusive fitness for both scenarios: First, consider the scenario where a first-year bird finds a mate and raises three offspring. The direct fitness gain is three offspring.
Consider the alternative scenario where the first-year bird helps its parents. By helping, the bird contributes to raising two additional offspring. Since these offspring are siblings, they share 50% of their genes with the helper bird. The indirect fitness gain is 0.5 * 2 = 1 offspring equivalent.
Compare the fitness outcomes: The direct fitness gain from breeding is three offspring, while the indirect fitness gain from helping is equivalent to one offspring. The direct fitness gain is higher.
Conclude based on kin selection theory: Since the direct fitness gain from breeding is greater than the indirect fitness gain from helping, the behavior of helping at the nest would not evolve in this population. Most first-year birds would choose to breed rather than help.