Body size and sexual size dimorphism in marine iguanas fluctuate as a result of opposing natural and sexual selection: An island comparison

Wikelski M, Trillmich F (1997)
EVOLUTION 51(3): 922-936.

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Wikelski, M; Trillmich, FritzUniBi
Abstract / Bemerkung
Body size is often assumed to represent the outcome of conflicting selection pressures of natural and sexual selection. Marine iguana (Amblyrhynchus cristatus) populations in the Galapagos exhibit 10-fold differences in body mass between island populations. There is also strong sexual size dimorphism, with males being about twice as heavy as females. To understand the evolutionary processes shaping body size in marine iguanas, we analyzed the selection differentials on body size in two island populations (max. male mass 900 g in Genovesa, 3500 g in Santa Fe). Factors that usually confound any evolutionary analysis of body sizes-predation, interspecific food competition, reproductive role division-are ruled out for marine iguanas. We show that, above hatchlings, mortality rates increased with body size in both sexes to the same extent. This effect was independent of individual age. The largest animals (males) of each island were the first to die once environmental conditions deteriorated (e.g., during El Ninos). This sex-biased mortality was the result of sexual size dimorphism, but at the same time caused sexual size dimorphism to fluctuate. Mortality differed between seasons (selection differentials as low as -1.4) and acted on different absolute body sizes between islands. Both males and females did not cease growth when an optimal body size for survival was reached, as demonstrated by the fact that individual adult body size phenotypically increased in each population under favorable environmental conditions beyond naturally selected limits. But why did marine iguanas grow ''too large'' for survival Due to lek mating, sexual selection constantly favored large body size in males (selection differentials up to +0.77). Females only need to reach a body size sufficient to produce surviving offspring. Thereafter, large body size of females was less favored by fertility selection than large size in males. Resulting from these different selection pressures on male and female size, sexual size dimorphism was mechanistically caused by the fact that females matured at an earlier age and size than males, whereafter they constantly allocated resources into eggs, which slowed growth. The observed allometric increase in sexual size dimorphism is explained by the fact that the difference between these selective processes becomes larger as energy abundance in the environment increases. Because body size is generally highly heritable, these selective processes are expected to lead to genetic differences in body size between islands. We propose a common-garden experiment to determine the influence of genetic factors and phenotypic reaction norms of final body size.
body size; Galapagos; growth; mortality; natural selection; phenotypic plasticity; sexual size dimorphism; sexual selection; allometry; Amblyrhynchus cristatus
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Wikelski M, Trillmich F. Body size and sexual size dimorphism in marine iguanas fluctuate as a result of opposing natural and sexual selection: An island comparison. EVOLUTION. 1997;51(3):922-936.
Wikelski, M., & Trillmich, F. (1997). Body size and sexual size dimorphism in marine iguanas fluctuate as a result of opposing natural and sexual selection: An island comparison. EVOLUTION, 51(3), 922-936.
Wikelski, M, and Trillmich, Fritz. 1997. “Body size and sexual size dimorphism in marine iguanas fluctuate as a result of opposing natural and sexual selection: An island comparison”. EVOLUTION 51 (3): 922-936.
Wikelski, M., and Trillmich, F. (1997). Body size and sexual size dimorphism in marine iguanas fluctuate as a result of opposing natural and sexual selection: An island comparison. EVOLUTION 51, 922-936.
Wikelski, M., & Trillmich, F., 1997. Body size and sexual size dimorphism in marine iguanas fluctuate as a result of opposing natural and sexual selection: An island comparison. EVOLUTION, 51(3), p 922-936.
M. Wikelski and F. Trillmich, “Body size and sexual size dimorphism in marine iguanas fluctuate as a result of opposing natural and sexual selection: An island comparison”, EVOLUTION, vol. 51, 1997, pp. 922-936.
Wikelski, M., Trillmich, F.: Body size and sexual size dimorphism in marine iguanas fluctuate as a result of opposing natural and sexual selection: An island comparison. EVOLUTION. 51, 922-936 (1997).
Wikelski, M, and Trillmich, Fritz. “Body size and sexual size dimorphism in marine iguanas fluctuate as a result of opposing natural and sexual selection: An island comparison”. EVOLUTION 51.3 (1997): 922-936.

44 Zitationen in Europe PMC

Daten bereitgestellt von Europe PubMed Central.

Effects of parasitic infection and reproduction on corticosterone plasma levels in Galápagos land iguanas, Conolophus marthae and C. subcristatus.
Onorati M, Sancesario G, Pastore D, Bernardini S, Cruz M, Carrión JE, Carosi M, Vignoli L, Lauro D, Gentile G., Ecol Evol 7(15), 2017
PMID: 28808564
Ecological and evolutionary influences on body size and shape in the Galápagos marine iguana (Amblyrhynchus cristatus).
Chiari Y, Glaberman S, Tarroso P, Caccone A, Claude J., Oecologia 181(3), 2016
PMID: 27041683
Mechanisms causing variation in sexual size dimorphism in three sympatric, congeneric lizards.
Manicom C, Alford R, Schoener TW, Schwarzkopf L., Ecology 95(6), 2014
PMID: 25039218
Resource assurance predicts specialist and generalist bee activity in drought.
Minckley RL, Roulston TH, Williams NM., Proc Biol Sci 280(1759), 2013
PMID: 23536593
Life-history and spatial determinants of somatic growth dynamics in Komodo dragon populations.
Laver RJ, Purwandana D, Ariefiandy A, Imansyah J, Forsyth D, Ciofi C, Jessop TS., PLoS One 7(9), 2012
PMID: 23028983
To breed or not to breed: physiological correlates of reproductive status in a facultatively biennial iguanid.
Vitousek MN, Mitchell MA, Romero LM, Awerman J, Wikelski M., Horm Behav 57(2), 2010
PMID: 19818354
Stress physiology as a predictor of survival in Galapagos marine iguanas.
Romero LM, Wikelski M., Proc Biol Sci 277(1697), 2010
PMID: 20504812
Genetic differentiation between marine iguanas from different breeding sites on the island of Santa Fe (Galapagos Archipelago).
Lanterbecq D, Glaberman S, Vitousek MN, Steinfartz S, Benavides E, Wikelski M, Caccone A., J Hered 101(6), 2010
PMID: 20538757
Progressive colonization and restricted gene flow shape island-dependent population structure in Galápagos marine iguanas (Amblyrhynchus cristatus).
Steinfartz S, Glaberman S, Lanterbecq D, Russello MA, Rosa S, Hanley TC, Marquez C, Snell HL, Snell HM, Gentile G, Dell'Olmo G, Powell AM, Caccone A., BMC Evol Biol 9(), 2009
PMID: 20028547
Are hotshots always hot? A longitudinal study of hormones, behavior, and reproductive success in male marine iguanas.
Vitousek MN, Rubenstein DR, Nelson KN, Wikelski M., Gen Comp Endocrinol 157(3), 2008
PMID: 18571171
Patterns of parasite abundance and distribution in island populations of Galápagos endemic birds.
Santiago-Alarcon D, Whiteman NK, Parker PG, Ricklefs RE, Valkiūnas G., J Parasitol 94(3), 2008
PMID: 18605785
Behavioral and physiological adjustments to new predators in an endemic island species, the Galápagos marine iguana.
Berger S, Wikelski M, Romero LM, Kalko EK, Rödl T., Horm Behav 52(5), 2007
PMID: 17904141
Genetic impact of a severe El Niño event on Galápagos marine iguanas (Amblyrhynchus cristatus).
Steinfartz S, Glaberman S, Lanterbecq D, Marquez C, Rassmann K, Caccone A., PLoS One 2(12), 2007
PMID: 18074011
Selective trade-offs and sex-chromosome evolution in Silene latifolia.
Scotti I, Delph LF., Evolution 60(9), 2006
PMID: 17089964
Steroid hormones and aggression in female Galápagos marine iguanas.
Rubenstein DR, Wikelski M., Horm Behav 48(3), 2005
PMID: 15916763
Genetic correlations with floral display lead to sexual dimorphism in the cost of reproduction.
Delph LF, Gehring JL, Arntz AM, Levri M, Frey FM., Am Nat 166 Suppl 4(), 2005
PMID: 16224710
Effect of tidal cycle and food intake on the baseline plasma corticosterone rhythm in intertidally foraging marine iguanas.
Woodley SK, Painter DL, Moore MC, Wikelski M, Romero LM., Gen Comp Endocrinol 132(2), 2003
PMID: 12812768
A comparative test of adaptive hypotheses for sexual size dimorphism in lizards.
Cox RM, Skelly SL, John-Alder HB., Evolution 57(7), 2003
PMID: 12940368
Marine iguanas die from trace oil pollution.
Wikelski M, Wong V, Chevalier B, Rattenborg N, Snell HL., Nature 417(6889), 2002
PMID: 12050651
The evolution of sexual size dimorphism in the house finch. III. Developmental basis.
Badyaev AV, Whittingham LA, Hill GE., Evolution 55(1), 2001
PMID: 11263737
Sexual dimorphism in steppe tortoises (Testudo horsfieldii): influence of the environment and sexual selection on body shape and mobility
PMID: IND44605721
Marine iguanas shrink to survive El Niño.
Wikelski M, Thom C., Nature 403(6765), 2000
PMID: 10638740
Sexual dimorphism in relation to current selection in the house finch.
Badyaev AV, Martin TE., Evolution 54(3), 2000
PMID: 10937271
Effects of el niño events on darwin's finch productivity
Grant PR, B. Rosemary Grant, Kenneth Petren, Lukas F. Keller., Ecology 81(9), 2000
PMID: IND605699297
The evolution of sexual size dimorphism in the house finch. II. Population divergence in relation to local selection.
Badyaev AV, Hill GE, Stoehr AM, Nolan PM, McGraw KJ., Evolution 54(6), 2000
PMID: 11209788
Density-dependent variation in lifetime breeding success and natural and sexual selection in Soay rams.
Coltman DW, Smith JA, Bancroft DR, Pilkington J, MacColl AD, Clutton-Brock TH, Pemberton JM., Am Nat 154(6), 1999
PMID: 10600616

107 References

Daten bereitgestellt von Europe PubMed Central.

Temporal variation in sexual size dimorphism of Anolis limifrons in Panama.
Andrews, Copeia 1994(), 1994
Arak A., Evolution 42(4), 1988
PMID: 28563875
Arnold SJ, Wade MJ., Evolution 38(4), 1984
PMID: 28555816
Arnold SJ, Wade MJ., Evolution 38(4), 1984
PMID: 28555830
A field study of temperature relations in the Galápagos marine iguana.
Bartholomew, Copeia 1966(), 1966
Heating and cooling rates, heart rate and simulated diving in the Galapagos marine iguana.
Bartholomew GA, Lasiewski RC., Comp. Biochem. Physiol. 16(4), 1965
PMID: 5881759
Consequences of sexual dimorphism in sand fiddler crabs, Uca pugilator: differential vulnerability to avian predation.
Bildstein, Anim. Behav. 37(), 1989
Macroecology: the division of food and space among species on continents.
Brown JH, Maurer BA., Science 243(4895), 1989
PMID: 17799895

Burghardt, 1982
Sexual selection and sexual dimorphism in some herbivorous lizards.
Carothers, Am. Nat. 124(), 1984
Body size differences between populations of the chuckwalla, Sauromalus obesus.
Case, Ecology 57(), 1976
Island/mainland body size differences in Australian varanid lizards.
Case TJ, Schwaner TD., Oecologia 94(1), 1993
PMID: 28313866

Charnov, 1993
Investigation of deaths in marine iguanas (Amblyrhynchus cristatus) on Galapagos.
Cooper JE, Laurie WA., J. Comp. Pathol. 97(2), 1987
PMID: 3597845
Zur geographischen Variation des Feinderkennens einiger Darwinfinken (Geospizinae).
Curio, Z. Tierpsychol. 26(), 1965

Darwin, 1883
Aufwand, Kosten und Nutzen der Fortpflanzung bei Meerechsen, Amblyrhynchus cristatus Bell 1825.
Dellinger, 1991
Bioenergetic scaling: metabolic design and body-size constraints in mammals.
Dobson GP, Headrick JP., Proc. Natl. Acad. Sci. U.S.A. 92(16), 1995
PMID: 7638188
Patterns of covariation in life history traits of squamate reptiles: the effects of size and phylogeny reconsidered.
Dunham, Am. Nat. 126(), 1985
Body size in island lizards: a cautionary tale.
Dunham, Ecology 59(), 1978
Das Verteidigen der Eiablageplätze bei der Hood-Meerechse (Amblyrhynchus cristatus venustissimus).
Eibl-Eibesfeldt, Z. Tierpsychol. 35(), 1966

Endler, 1986
Factors influencing sexual size dimorphism in temperate water striders.
Fairbairn, Am. Nat. 136(), 1990
Sexual selection and the evolution of allometry for sexual size dimorphism in the water strider, Aquarius remigis.
Fairbairn, Am. Nat. 144(), 1994
Variation in sexual size dimorphism and maximum body size among adder populations-effects of prey size.
Forsman, J. Anim. Ecol. 60(), 1991
Survival in relation to body-size and growth-rate in the adder, Vipera berus.
Forsman, J. Anim. Ecol. 62(), 1993
The largest, smallest, highest, lowest, longest, and shortest: extremes in ecology.
Gaines, Ecology 74(), 1993

Grant, 1989

Grant, 1986
Sexual differences in contemporary selection acting on size in the hermit-crab Clibanarius digueti.
Harvey, Am. Nat. 136(), 1990
Insular radiation in life-history of the lizard Eumeces okadae in the Izu islands, Japan.
Hasegawa, Copeia 1994(), 1994
The evolution of sexual dimorphism in animals: Hypotheses and tests.
Hedrick AV, Temeles EJ., Trends Ecol. Evol. (Amst.) 4(5), 1989
PMID: 21227335
EI Nino Metamorphosis Throws Forecasters.
Kerr RA., Science 262(5134), 1993
PMID: 17812332
Sexual size dimorphism: a life history perspective.
Kozlowski, Oikos 54(), 1989
Optimal initial size and adult size of animals: consequences for macroevolution and community structure.
Kozlowski, Am. Nat. 147(), 1996
Indices of condition for small mammals.
Krebs, Aust. J. Zool. 41(), 1993
Genetic Correlations between the sexes in the evolution of sexual dimorphism and mating preferences.
Lande, 1987
Effects of the 1982-83 El Niño-Southern Oscillation event on marine iguana (Amblyrhynchus cristatus, Bell, 1825) populations in the Galápagos islands.
Laurie, 1989
Population biology of marine iguanas (Amblyrhynchus cristatus). 1. Changes in fecundity related to a population crash.
Laurie, J. Anim. Ecol. 59(), 1990
Population biology of marine iguanas (Amblyrhynchus cristatus). 2. Changes in annual survival rates and the effects of size, sex, age and fecundity in a population crash.
Laurie, J. Anim. Ecol. 59(), 1990
Population biology of marine iguanas (Amblyrhynchus cristatus). 3. Factors affecting survival.
Laurie, J. Anim. Ecol. 59(), 1990
Extra-large body size in California voles-causes and fitness consequences.
Lidicker, Oikos 61(), 1991
Seasonality, fasting endurance, and body size in mammals.
Lindstedt, Am. Nat. 125(), 1985
Sex and age dimorphism in the barn owl and a test of mate choice.
Marti, Auk 107(), 1990
Trends in body-size evolution.
McKinney, 1990
Natural selection and the heritability of fitness components.
Mousseau TA, Roff DA., Heredity (Edinb) 59 ( Pt 2)(), 1987
PMID: 3316130
The evolution of reversed sexual dimorphism in size in monogamous species of birds.
Mueller, Biol. Rev. Camb. Phil. Soc. 65(), 1990
Reciprocal transplant reveals sources of variation in growth-rates of the lizard Sceloporus undulatus.
Niewiarowski, Ecology 74(), 1993
Assessment strategy and the evolution of fighting behaviour.
Parker GA., J. Theor. Biol. 47(1), 1974
PMID: 4477626
Genetical processes in the Galapagos
PATTON JL., Biol. J. Linn. Soc. Lond. 21(1/2), 1984
PMID: IND44598153
Sexual selection, lek and arena behaviour, and sexual size dimorphism in birds.
Payne, Ornithol. Monogr. 33(), 1984

Peters, 1983
Capture-recapture models allowing for age-dependent survival and capture rates.
Pollock, Biometrics 37(), 1981
Sexual size dimorphism and parental care patterns in a monomorphic and a dimorphic larid.
Quinn, Auk 107(), 1992
Reinventing the wheel -analysis of sexual dimorphism in body-size.
Ranta, Oikos 70(), 1994

Female habitat choice as a determinant of the reproductive success of the territorial male marine iguana (Amblyrhynchus cristatus).
Rauch, Behav. Ecol. Sociobiol. 16(), 1985
Competition of marine iguana females Amblyrhynchus cristatus for egg-laying sites.
Rauch, Behaviour 107(), 1988

Reiss, 1989
The evolution of behavioral phenotypes-lessons learned from divergent spider populations.
Riechert, Adv. Study Behav. 22(), 1993
Schmidt-Nielsen, 1984
Population structure of black tiger snakes, Notechis ater niger, on offshore islands of South Australia.
Schwaner, 1985
Body size and sexual dimorphism in mainland and island tiger snakes.
Schwaner, J. Herpetol. 24(), 1990
SEBER GA., Biometrika 52(), 1965
PMID: 14341277
Sexual size dimorphism and male combat in snakes.
Shine R., Oecologia 33(3), 1978
PMID: 28309592
Proximate determinants of sexual differences in adult body size.
Shine, Am. Nat. 135(), 1990
Intersexual dietary divergence and the evolution of sexual dimorphism in snakes.
Shine, Am. Nat. 138(), 1991
Allometric patterns in the ecology of Australian snakes.
Shine, Copeia 1994(), 1994
Sexual size dimorphism in snakes revisited.
Shine, Copeia 1994(), 1994
Size of Galapagos land iguanas: episodic selection resolves a paradox.
Snell, Am. Zool. 27A(), 1987
Intrapopulation variation in predator-avoidance performance of Galápagos lava lizards: the interaction of sexual and natural selection.
Snell, Evol. Ecol. 2(), 1988

SPSS, 1991
Estimating asymptotic size using the largest individuals per sample.
Stamps, Oecologia 62(), 1992
Analyses of sexual size dimorphism using null growth-based models.
Stamps, Copeia 1994(), 1994

Stearns, 1992
Growth-rate, timing of reproduction, and size dimorphism in the southwestern earless lizard (Cophosaurus texanus scitulus).
Sugg, Southwest. Nat. 40(), 1995
Locomotor performance of hatchling fence lizards (Sceloporus occidentalis): quantative genetics and morphometric correlates.
Tsuji, Evol. Ecol. 3(), 1989
The mating systems of pinnipeds and marine iguanas: convergent evolution of polygyny
TRILLMICH F, TRILLMICH KGK., Biol. J. Linn. Soc. Lond. 21(1/2), 1984
PMID: IND44598144
The mating system of the Marine Iguana (Amblyrhynchus cristatus).
Trillmich, Z. Tierpsychol. 63(), 1983
Foraging strategies of the marine iguana, Amblyrhynchus cristatus.
Trillmich, Behav. Ecol. Sociobiol. 18(), 1986
Holocene dwarf mammoths from Wrangel Island in the Siberian Arctic.
Vartanyan, Nature 362(), 1993
Sexual selection, natural selection, and body size in Gammarus pulex (Amphipoda).
Ward, Am. Nat. 131(), 1988
Kinship recognition and grouping in hatchling green iguanas.
Werner, Behav. Ecol. Sociobiol. 21(), 1987
Temperature and the Galapagos marine iguana--insights into reptilian thermoregulation.
White FN., Comp Biochem Physiol A Comp Physiol 45(2), 1973
PMID: 4145444
Pre-copulatory ejaculation solves time constraint during copulations in marine iguanas.
Wikelski, Proc. R. Soc. Lond. B Biol. Sci. 263(), 1996
Is there an endogenous tidal foraging rhythm in marine iguanas?
Wikelski M, Hau M., J. Biol. Rhythms 10(4), 1995
PMID: 8639942
Foraging strategies of the Galapagos marine iguana (Amblyrhynchus cristatus): adapting behavioral rules to ontogenetic size change.
Wikelski, Behaviour 128(), 1994
Lekking in marine iguanas: female grouping and male reproductive strategies.
Wikelski, Anim. Behav. 52(), 1996


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