week 1 -paper - costs of reproduction and terminal investment by females in a semelparous marsupial Flashcards
fisher and bloomberg 2011
fisher and bloomberg 2011
What are evolutionary explantions for life history diversity based on?
The idea of costs of reproduction, particularly on the concept of a trade off between age-specific reproduction and parental survival and between expenditure on current and future offspring
What is the terminal investment theory?
Predicts that reproductive effort by older parents should increase, because individuals offspring become more valuable to parents as the conflict between current versus potential future offspring declines with age
How can you demonstrate the terminal investment thoery in nature?
In females there must be an increase in maternal expenditure on offspring with age, imposing a fitness cost on the mother
what did fisher and bloomberg do in this study?
quantify the costs of reproduction throughout the life spand of female antechinuses
Explain the study species
Antechinuses are small, nocturnal, marsupials
unlike most other mammals all males and most females are semelparous
what did the study find
increased allocation to current reproduction reduces maternal survival and that offspring growth and survival in the first breeding season is traded off with performance of the 2nd litter in iteroparous females
In iteroparous females increased allocation to second litters is associated with severe weight loss in late lactation and post lactation death of mothers but increase offspring growth in late lactation and survival to weaning.
why are the findings significant?
these findings are consistent with terminal investment theory.
iteroparity did not increase life time reproductive success indicating that terminal investment in the first breeding season at the expense of maternal survival is likely to be advantageous for females.
