Skip to main content

Archived Comments for: Evolutionary origins of insulin resistance: a behavioral switch hypothesis

Back to article

  1. Reconciliation of thriftiness and behavioural switch

    Prajakta Belsare, Abasaheb Garware College

    19 March 2008

    The hypothesis by Watve and Yajnik is an entirely novel way of thinking, hard to believe at the first look but largely supported by evidence. However, the way the authors criticize the thrifty gene and thrifty phenotype hypothesis gives an impression that their hypothesis is an incompatible alternative to the thriftiness family. In reality it need not be so.

    There are aspects on which the two hypotheses converge and compliment each other. Studies on a wide variety of species show that metabolic rates and reproductive strategies are correlated. Empirical and theoretical ecologists have repeatedly talked about a positive correlation between metabolic rate and reproductive rate (1-5). The r selection strategy of this paper implies high reproductive rate and therefore higher metabolic rate as well. On the other hand K-selection should be accompanied by lower metabolic rates. Lower metabolic rate is also central to thriftiness. Therefore the two hypotheses are certainly compatible to each other and thriftiness due to low RMR can be viewed as an essential subset of K strategy of life cycle.

    1. Kam M, Cohen-Gross s, Khokhlova IS, Degen AA, Geffen E: Average daily metabolic rate, reproduction and energy allocation during lactation in the Sundevall Jird Meriones crassus. Funct Ecol 2003, 17: 496-503.

    2. Hennemann WW: Relationship among body mass, metabolic rate and the intrinsic rate of natural increase in mammals. Oecologia 1983, 56: 104-108.

    3. Fenchel T: Intrinsic rate of natural increase: the relationship with body size. Oecologia 1974, 14: 317-326.

    4. Boyce MS, Restitution of gamma- and K- selection as a model of density dependent natural selection. Ann Rev Ecol Sys 1984: 15: 427-447.

    5. Stephenson PJ, Racey PA, Resting metabolic rate and reproduction in insectivora. Comp Biochem Physiol A: Physiol 1995: 112: 215-223.

    Competing interests