Question

Lack's hypothesis was first proposed by David Lack in 1947. What is Lack’s hypothesis regarding ideal clutch size? Is his hypothesis supported by experimental data? On the figure below mark where/ indicate the ideal clutch size according to Lack. We discussed three alternative hypotheses (trade-offs or alternative strategies) for why populations may deviate from Lack hypothesis. List those three hypotheses below and briefly discuss each.

Lack's hypothesis was first proposed by David Lack in 1947. What is Lack's hypothesis regarding ideal clutch size? Is his hypothesis supported by experimental data? On the figure below mark where/ indicate the ideal clutch size according to Lack. We discussed three alternative hypotheses (trade-offs or alternative strategies) for why populations may deviate from Lack hypothesis. List those three hypotheses below and briefly discuss each. Frequency distribution Young per clutch 1.0 Frequency Young per clutch 1 3 5 13 15 17 7 9 11 Clutch size

Answer 1

Lacks hypothesis states that the clutch size of a particular species adapted by the process of natural selection and correspond to the maximum number of young ones that can be fed by the parent.

Taking into consideration the reproductive success an ideal clutch size is 5 which provides a probability of 2.5 live offaprings.

From the graph it is clear that the ideal clutch size for this population of birds is around 8.

Deviation from Lacks hypotheis:

a) Competition in specis not considered.

b) final nestling to hatch factor

c)Asynchrony in hatching over the years