Tools of Evolutionary Biology Summary

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Research Paper Citation : JOHNSON, J. C., MILES, L. S., TRUBL, P. J. & HAGENMAIER, A. 2014. Maternal effects on egg investment and offspring performance in black widow spiders. Animal Behaviour, 91, 67-73.

Q.1 The study addressed questions like what effects maternal foraging success would have on maternal body condition, fecundity, egg investment and whether an abundance in prey for the mother would have positive effects on offspring traits like shapes maternal body condition, fecundity and egg investment, and that maternal prey abundance has a positive, cross-generational effect on a number of important offspring traits, for example, sibling cannibalism in black widow spiders.

Q.2 The findings of this study include the knowledge that maternal foraging success is indeed responsible for better maternal body condition, egg sac mass, egg number, mass, size and density rate. Some exceptions were also observed where the mothers given the high-nutrition treatment made low-density eggs and some given low-nutrition treatment made high-density eggs, showing that these characters are also influenced by genetic traits of the individual. Sibling cannibalism is also seen shown to be fitness-related, genetically effected trait.

Q.3 The experiment consisted of manipulating the food intake of black widow spider mothers, a high-nutrition and a low-nutrition diet were used. Eighteen penultimate-stage juvenile black widow spiders were

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