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LIFE HISTORY VARIATION IN MAMMALS, BIRDS AND REPTILES

Objective


Research groups working in France and England collaborated to develop the following:
databases on life history variation in vertebrate mammals;
methods of analysis for such data to determine the evolutionary pressures responsible for the diversity;
mathematical models to unify the theoretical framework;
understanding of the ecological context of life history differences so that conservation decisions could be better informed. Specific studies are as follows:

Components of fecundity that change with mortality:
Age at maturity seemed to be the most plastic character which varied quite dramatically across species in accord with mortality schedules.

Life history pacemakers: testing the theories:
It has been suggested that 2 pacemakers for life history evolution were metabolic rate and brain size. Analyses demonstrated that for neither birds nor mammals was metabolic turnover a significant correlate of life history variation, independently of body size. Brain size did not vary with either metabolic turnover or life history when the effects of body size were removed.

Growth curves, maternal investment and demographic strategies:
Two broad strategies seem to have evolved in mammals:
to have many reproductive attempts spread over a long reproductive life with a few well developed young at each reproductive attempt, allowing a high investment per individual offspring;
to have few reproductive attempts concentrated in a short reproductive life with many poorly developed young at each reproductive attempt, allowing only a low investment per individual offspring.

Comparative methodology:
A software package has been developed to implement the new comparative methods.

Community structure, phylogeny and life history:
A new set of methodologies have been developed for phylogenetic analysis of community structure, taking into account life history characteristics in the phylogenetic tree structure which is itself based on speciation and extinction rates.
The time has come to move from the descriptive phase of life history variation in reptiles, birds and mammals. Crucial decisions concerning the conservation and management of endangered species depend on understanding how reproductive rates vary with ecology and taxonomy. Reproductive parameters such as litter size, parental investment, and age at sexual maturity evolve in an ecological context. Techniques developed at the Universities of Oxford, Lyon, Montpellier and Reading will be combined to derive and test
explanations for species differences in reproductive parameters. This integrated development and analysis of a common database by population analysts, comparative biologists, evolutionists,
ecologists and statisticians will provide a comprehensive
interpretation of avian and mammalian life histories.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF OXFORD
Address
University Offices, Wellington Square
Oxford
United Kingdom

Participants (1)

Centre National de la Recherche Scientifique (CNRS)
France
Address
43 Boulevard Du 11 Novembre 1918
69622 Villeurbanne