Evol Ecol Res 2: 1067-1071 (2000)     Full PDF if your library subscribes.

Dimensionless invariants for the optimal size (age) of sex change

Eric L. Charnov¹ and Unnur Skúladóttir²

¹Department of Biology, The University of New Mexico, Albuquerque, NM 87131-1091, USA and ²Marine Research Institute, Skúlagata 4, PO Box 1390, IS-121 Reykjavík, Iceland

Author to whom all correspondence should be addressed.

ABSTRACT

Optimization models have been widely and successfully used in evolutionary ecology to predict the attributes of organisms; perhaps the greatest quantitative success is in the area of sex allocation (sex ratio, sperm versus eggs for hermaphrodites, time as a male [female] for a sex changer), where the fact of having only one mother and one father makes Darwinian fitness a simple product of gain-via-male times gain-via-female. Previous work on sex change used the maximization of this male–female product to successfully predict the direction and age (size) for sex change, and that age has been shown to imply a breeding sex ratio biased towards the first sex. This paper unites recent advances in the comparative demography of organisms with indeterminant growth with the theory of optimal sex change to predict some new invariance rules for the relative age (size) of sex change. One of these rules is strikingly confirmed in a long-term study of the size-at-sex-change in the northern shrimp, Pandalus borealis, off Iceland.

Keywords: dimensionless analysis, evolutionarily stable strategy, life history, sex allocation.

DOWNLOAD A FREE, FULL PDF COPY
IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.

 

        © 2000 Eric L. Charnov. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.

       Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.

       All copies of abstracts and articles must preserve their copyright notice without modification.