BIOL 122 Lecture Notes - Lecture 12: Parental Investment, David Lack, Fecundity
Document Summary
However, there are times when this tradeoff is not observed (absent) Selection favors offspring of an optimal size. Any additional energy can only increase offspring # The more offspring produced, the less care each individual receives. Should be an optimal # of offspring to produce. Birds at higher latitudes have more daylight hours to forage for their young annually. Lay just enough eggs to maximize the # of offspring they can. Parents with intermediate sized broods were most fit. Adding eggs to the nest increases competition among the young. Having more young to feed puts an energetic strain on the parents. Makes parents more susceptible to predation (and chicks) If eggs are removed, parental survival increases but fecundity decreases. If eggs are added, parental survival decreases but fecundity increases but the offspring are malnourished. Parental investment is a tradeoff between current reproductive success and longevity. Fitness of an individual offspring generally increases with parental expenditure.
