Does the relationship between offspring size and performance change across the life-history?

Dias, G. M. and Marshall, D. J. (2010) Does the relationship between offspring size and performance change across the life-history?. Oikos, 119 1: 154-162. doi:10.1111/j.1600-0706.2009.17725.x

Author Dias, G. M.
Marshall, D. J.
Title Does the relationship between offspring size and performance change across the life-history?
Journal name Oikos   Check publisher's open access policy
ISSN 0030-1299
Publication date 2010-01
Year available 2009
Sub-type Article (original research)
DOI 10.1111/j.1600-0706.2009.17725.x
Volume 119
Issue 1
Start page 154
End page 162
Total pages 9
Place of publication Malden, MA, United States
Publisher Wiley-Blackwell Publishing
Collection year 2010
Language eng
Subject C1
970106 Expanding Knowledge in the Biological Sciences
060308 Life Histories
Abstract What selection pressures drive the evolution of offspring size? Answering this fundamental question for any species requires an understanding of the relationship between offspring size and offspring fitness. A major goal of evolutionary ecologists has been to estimate this critical relationship, but for organisms with complex lifecycles, logistical constraints restrict most studies to early life-history stages only. Here, we examine the relationship between offspring size and offspring performance in the field across multiple life-history stages and across generations in a marine invertebrate .We then use these data to parameterise a simple optimality model to generate predictions of optimal offspring size and determined whether these predictions depended on which estimate of offspring performance was used. We found that offspring size had consistently positive effects on performance (estimated as post-metamorphic growth, fecundity and reproductive output). We also found that manipulating the experience of offspring during the larval phase changed the way in which offspring size affects performance: offspring size affected post-metamorphic growth when larvae were allowed to settle immediately but offspring size affected survival when larvae were forced to swim prior to settlement. Despite finding consistently positive effects of offspring size, early measures of the effect of offspring size resulted in the systematic underestimation of optimal offspring size. Surprisingly, the amount of variation in offspring performance that offspring size explained decreased with increasing time in the field but the steepness of the relationship between offspring size and performance actually increased. Our results suggest caution should be exercised when empirically examining offspring size effects - it may not be appropriate to assume that early measures are a good reflection of the actual relationship between offspring size and fitness. © 2009 Oikos.
Keyword Ascidian Diplosoma-listerianum
Colonial marine invertebrate
Post-metamorphic Performance
Trout Salmo-trutta
Egg Size
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Published Online: 14 Aug 2009

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2010 Higher Education Research Data Collection
School of Biological Sciences Publications
Ecology Centre Publications
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Citation counts: TR Web of Science Citation Count  Cited 17 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 17 times in Scopus Article | Citations
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Created: Sun, 10 Jan 2010, 00:02:42 EST