For autosomal allele copies under the lesson's outbred diploid pedigree assumptions, what does expected relatedness r = 1/4 mean?

• An expected quarter is shared by recent descent.
• A quarter of behavior is inherited; the rest is learned.
• A quarter of each benefit returns directly to the helper.

Two full siblings share both parents in a diploid pedigree. Their ancestors are unrelated and non-inbred. Each shared parent gives a two-link path between them. What is their expected relatedness r?

• 1/4: use one shared-parent path and leave out the other.
• 1/2: add both shared-parent paths, each contributing 1/4.
• 2: add the four link factors without multiplying along paths.

Two unrelated individuals take turns removing parasites from each other. Which mechanism could maintain helping through later returns?

• Kin selection: familiarity raises pedigree relatedness.
• Kin selection: belonging to one species gives every pair full-sibling relatedness.
• Reciprocity: later help provides a return benefit to the earlier helper.

In the lesson's additive model, r = 0.5, B = 8 and C = 4 in matching fitness units. Does the claim 'there is no net advantage from helping in this comparison' fit these values?

• Yes. The weighted benefit equals the cost, giving zero net gain.
• No. A positive raw benefit is enough to favor helping.
• No. At equality, the heritable helping trait is selected against.

In the lesson's additive model, r = 0.5, B = 6 and C = 2 in matching fitness units. What is the relatedness-weighted benefit r times B?

A nonreproducing worker helps the queen raise related offspring. What can this add without the worker producing its own offspring?

• Direct fitness, because the queen's offspring count as the worker's own offspring.
• Indirect fitness, by helping related offspring survive and reproduce.
• Pedigree relatedness, because feeding relatives changes their inherited ancestry.

In the lesson's additive model, a recipient has r = 0 and the helper has C > 0. A positive benefit B to this recipient alone makes r times B > C.

In the lesson's one-recipient additive model, the same helping act has B = 12 and C = 4 in matching fitness units. Compare a full sibling with r = 0.5 and a recipient assigned r = 0. For which recipient is helping favored, and why?

• Neither: the direct cost of 4 prevents helping even when the recipient is a full sibling.
• Both: the benefit of 12 exceeds 4, so relatedness does not change whether helping is favored.
• Only the full sibling: its weighted benefit is 6, while the other recipient's is 0.