Question

From an offspring's perspective, its siblings are not as valuable as itself, because its siblings have a coefficient of relationship of 0.5 (compared to its coefficient of relationship to itself of 1.0). Offspring should thus compare the benefit (B) of accepting additional care from their parents to the cost (C) this care represents for future reproductive success (production of more full siblings) of their parents. When the benefit:cost (B:C) ratio falls below one of the following values an offspring will cease to accept additional care from its parents. Which value is it?

1) 2.0
2) 1.0
3) 0.5
4) 0.25

Answer 1

An offspring should cease to accept additional care from its parents when the benefit to cost ratio falls below 0.25, considering its siblings have only half the genetic investment compared to itself. Parental investment strategies vary, with long-term care leading to fewer offspring and high fecundity associated with little parental care but many offspring to ensure species survival.

Step-by-step explanation:

From the perspective of an offspring, its own reproductive success is of the highest priority. The offspring should cease to accept additional care from its parents when the benefit to cost (B:C) ratio falls below 1, specifically at the value of 0.25. This ratio highlights the balance between the benefits of parental care for the offspring and the cost that such care incurs on the parents' ability to produce future offspring. Since siblings share only a coefficient of relationship of 0.5, the offspring views resources spent on itself as twice as valuable compared to those spent on a sibling.

Long-term parental care generally leads to fewer offspring, which can result in a greater risk to the survival of the species should a single offspring not survive. On the contrary, organisms with high fecundity have many offspring and provide little parental care, allowing for enough offspring to survive despite high predation rates. This is associated with a tradeoff, where energy is used for producing offspring rather than parental care to maximize evolutionary fitness.