Question

In cooperatively breeding animals, offspring from one year stay back and help their parents to rear offspring born in successive breeding episodes. Kin selection has been used to explain such helping behaviour. Which of the following support the kin selection hypothesis?

• A. Helpers provide more care in populations where extra-pair paternity is low, than in populations where extra-pair paternity is high.
• B. Individuals who choose to stay and help are more likely to inherit their parents' territory than individuals who stay but do not help.
• C. Individuals who choose to disperse from their natal territory rather than stay and help have a lower survival because of predation during dispersal, when compared with individuals who stay and help.
• D. Helpers whose parents continue to form the breeding pair provide more care than helpers whose parents are replaced by a new breeding pair.

Hint:

Helpers invest more in closely related kin.

Answer 1

The Correct Option is A, D

The question is about cooperatively breeding animals and the concept of kin selection. In these species, offspring might remain with their parents to help raise subsequent generations of offspring. The kin selection hypothesis suggests such behavior is favored because it helps spread shared genes. Let's analyze the given statements to check which ones support the kin selection hypothesis:

1. Helpers provide more care in populations where extra-pair paternity is low, than in populations where extra-pair paternity is high.

   This statement supports the kin selection hypothesis. In populations where extra-pair paternity is low, helpers are more likely to be assisting their genetic siblings. Thus, their inclusive fitness is higher when they help rear offspring that have a higher chance of sharing their genes. When extra-pair paternity is high, the likelihood of raising siblings is lower, hence less care.

2. Individuals who choose to stay and help are more likely to inherit their parents' territory than individuals who stay but do not help.

   This option highlights potential direct benefits rather than kin selection. While inheriting territory can offer personal advantages, it doesn't necessarily reflect helping improve the reproductive success of genetic relatives, as highlighted by kin selection.

3. Individuals who choose to disperse from their natal territory rather than stay and help have a lower survival because of predation during dispersal, when compared with individuals who stay and help.

   This statement concerns survival risk, which can certainly influence behavior, but it centers on personal survival advantage rather than increasing the reproductive success of genetic relatives, which is central to kin selection.

4. Helpers whose parents continue to form the breeding pair provide more care than helpers whose parents are replaced by a new breeding pair.

   This statement supports the kin selection hypothesis as well. If the original parents remain, the helpers have a greater genetic stake in ensuring the survival of their siblings (new offspring). If the parents are replaced, the new offspring may not be genetic siblings, hence less motivation for helping under the kin selection framework.

Based on the analysis, the statements supporting the kin selection hypothesis are:

• Helpers provide more care in populations where extra-pair paternity is low, than in populations where extra-pair paternity is high.
• Helpers whose parents continue to form the breeding pair provide more care than helpers whose parents are replaced by a new breeding pair.

These options align with kin selection because they involve helping behavior that enhances the reproductive success of individuals with whom the helpers share more genes.