Physiological costs of growing fast: does accelerated growth reduce pay-off in adult fitness?

Abstract

Accumulating evidence suggests that, in contrast to earlier assumptions, juvenile growth rates are optimised by means of natural and sexual selection rather than maximised to be as fast as possible. Owing to the generally accepted advantage of growing fast to adulthood, such adaptive variation strongly implies the existence of costs attached to rapid growth. By using four populations of protandrous copper butterflies with known differences in intrinsic growth rates within and across populations, we investigate a potential trade-off between rapid growth and the proportionate weight loss at metamorphosis. While controlling for effects of pupal time and mass, we demonstrate that (1) protandrous males, exhibiting higher growth rates, suffer a higher weight loss than females throughout, that (2) population differences in weight loss generally follow known differences in growth rates, and that (3) males have by 6% higher metabolic rates than females during pupal development. These results support the notion that a higher weight loss during the development to adulthood may comprise a physiological cost of rapid development, with the payoff of accelerated growth being reduced by a disproportionally smaller adult size.

Exploring plastic and genetic responses to temperature variation using copper butterflies

“…For 2 reasons a higher body mass in high-altitude animals was expected: (1) because body size is typically larger in cooler environments (Bergmann size clines extended to ectotherms; Atkinson 1994, Angilletta & Dunham 2003, but see Kingsolver et al 2007), and (2) because the accelerated development in low-altitude populations should be associated with a smaller body size (cf. Fischer & Fiedler 2002b, Fischer et al 2004. Thus the lack of differentiation found here highlights the notion that associations between body size and environmental (temperature) variation are more complex than previously thought, and may range from positive to negative , Blanckenhorn & Demont 2004, Iraeta et al 2006, Cvetkoviç et al 2009).…”

“…Differences in growth rates among sexes, populations and temperatures were generally associated with an analogous variation in the weight loss at metamorphosis. Thus weight loss increased with increasing temperature, was higher in more rapidly developing populations than in more slowly developing ones, and was higher in males than in females (Fischer et al 2004). This has been interpreted as a physiological cost of rapid growth, with the payoff of accelerated growth being reduced by a disproportionally smaller adult size (Fischer et al 2004).…”

“…Thus weight loss increased with increasing temperature, was higher in more rapidly developing populations than in more slowly developing ones, and was higher in males than in females (Fischer et al 2004). This has been interpreted as a physiological cost of rapid growth, with the payoff of accelerated growth being reduced by a disproportionally smaller adult size (Fischer et al 2004). In males, a 6% higher metabolic rate compared to females was found during pupal development, which may cause the differences in weight loss (Fischer et al 2004).…”

“…A series of studies investigated plasticity in life-history traits and life cycles in response to temperature and other environmental variables in L. tityrus and L. hippothoe (e.g. Fischer & Fiedler 2000a,b, 2001b,c, 2002a, Fischer et al 2004, Karl & Fischer 2008, while others focussed on altitudinal variation and the functional significance of allelic variation at the phosphoglucose isomerase (PGI) locus (Karl et al 2008a(Karl et al ,b, 2009b. Finally, copper butterflies were used to address questions within a conservation context, e.g.…”

“…This has been interpreted as a physiological cost of rapid growth, with the payoff of accelerated growth being reduced by a disproportionally smaller adult size (Fischer et al 2004). In males, a 6% higher metabolic rate compared to females was found during pupal development, which may cause the differences in weight loss (Fischer et al 2004). …”