Parental Care (L16) T3

Question 1

Major benefit and cost of parental care?

Answer 1

Benefit: Increased survivorship of young

Cost: Less offspring produced

Question 2

Origin of maternal care: Size of Gamete Hypothesis

Answer 2

• Females invest more energy than males by contributing a larger gamete to the zygote.
• Females are predisposed to provide proportionately more parental care.
• Problem: males sometimes provide the parental care.

Question 3

Origin of maternal care: Low reliability of paternity hypothesis

Answer 3

• Females are more likely than males to be the parent of assisted offspring.
• The sexually produced offspring of a female will always have 50% of her genes.
• A male has no certainty that his mate’s offspring have his genes.
• The probability of paternity is greater if fertilization is external because the eggs can be seen while being fertilized by the male.
• If paternal males produce more surviving offspring than non-paternal males, paternal behavior should increase within the population regardless of the reliability of paternity.

Question 4

Origin of maternal care: Order of gamete release hypothesis

Answer 4

• The sex that provides care is determined by the order in which eggs and sperm are released.
• Whichever sex can leave first after mating will do so, leaving the other to care for the offspring if parental care.
• When fertilization is INTERNAL, males are free to leave after mating, leaving females with the option of providing parental care.
• When fertilization is EXTERNAL, females often deposit their eggs before males shed sperm, giving females the opportunity to leave first.

Question 5

Original of maternal care: Association with young hypothesis

Answer 5

• The sex that is associated with the offspring when they emerge is more likely to provide parental care.
• females have more control over the birth of offspring, thus are more likely to provide parental care.

Question 6

Maximizing parental care

Answer 6

• Parents should deliver parental care only to their own offspring.
• Parents should be able to recognize their own offspring.
• Recognition of young is more prevalent in colonial species.

Question 7

Infanticide, ovicide, filial infanticide, and siblicide

Answer 7

Infanticide: Killing of young by adults of the same species.

Ovicide: killing of eggs by adults of the same species.

filial infanticide: Killing of offspring by parents.

Siblicide: One sibling killing another.

Question 8

Adaptive sibling rivalry hypothesis

Answer 8

Parents benefit by chicks eliminating members of brood who are unlikely to survive and reproduce.

Assumes: Reproductive success depends on number of offspring actually reaching age of reproduction, not the number of young surviving.