@article {1567,
	title = {Diversity in the weapons of sexual selection: horn evolution in the beetle genus Onthophagus (Coleoptera: Scarabaeidae)},
	journal = {Evolution},
	volume = {59},
	number = {5},
	year = {2005},
	month = {Jan},
	pages = {1060-1084},
	abstract = {Both ornaments and weapons of sexual selection frequently exhibit prolific interspecific diversity of form. Yet, most studies of this diversity have focused on ornaments involved with female mate choice, rather than on the weapons of male competition. With few exceptions, the mechanisms of divergence in weapon morphology remain largely unexplored. Here, we characterize the evolutionary radiation of one type of weapon: beetle horns. We use partial sequences from four nuclear and three mitochondrial genes to develop a phylogenetic hypothesis for a worldwide sample of 48 species from the dung beetle genus Onthophagus (Coleoptera: Scarabaeidae). We then use these data to test for multiple evolutionary origins of horns and to characterize the evolutionary radiation of horns. Although our limited sampling of one of the world{\textquoteright}s most species-rich genera almost certainly underestimates the number of evolutionary events, our phylogeny reveals prolific evolutionary lability of these exaggerated sexually selected weapons (more than 25 separate gains and losses of five different horn types). We discuss these results in the context of the natural history of these beetles and explore ways that sexual selection and ecology may have interacted to generate this extraordinary diversity of weapon morphology. },
	keywords = {Adaptive radiation, beetle horns, character divergence, male competition, Onthophagus, phylogeny, sexual selection, weapons.},
	author = {Emlen, Douglas J. and Marangelo, Jennifer and Ball, Bernard and Cunningham, Clifford}
}
@article {1791,
	title = {Genital morphology and fertilization success in the dung beetle Onthophagus taurus: an example of sexually selected male genitalia},
	journal = {Proceedings of the Royal society of London B},
	volume = {270},
	year = {2003},
	pages = {447-455},
	abstract = {In animals with internal fertilization and promiscuous mating, male genitalia show rapid and divergent evolution. Three hypotheses have been suggested to explain the evolutionary processes responsible for genital evolution: the lock-and-key hypothesis, the pleiotropy hypothesis and the sexual-selection hypoth- esis. Here, we determine whether variation in male genital morphology influences fertilization success in the dung beetle Onthophagus taurus, as predicted by the sexual-selection hypothesis. Variation in four out of five genital sclerites of the endophallus influenced a male{\textquoteright}s fertilization success, supporting the general hypothesis that male genitalia can evolve under sexual selection. Furthermore, different genital sclerites were found to enhance first versus second male paternity, indicating that different sclerites serve offensive and defensive roles. Genital-trait variability was comparable to that in other species but was less variable than a non-genital sexually selected trait (head horns). We suggest that directional selection for genital elaboration may be countered by natural selection, which should favour genitalia of a size and shape necessary for efficient coupling and sperm transfer. },
	keywords = {male genitalia, Onthophagus, paternity, sexual selection, Sperm competition},
	author = {House, Clarissa M. and Simmons, Leigh W.}
}
@article {1870,
	title = {Sexual selection and condition dependence of courtship display in three species of horned dung beetles},
	journal = {Behavioral Ecology},
	volume = {13},
	number = {6},
	year = {2002},
	note = {Times Cited: 0Cited Reference Count: 62Cited References:      ANDERSSON M, 1986, EVOLUTION, V40, P804     ANDERSSON M, 1994, SEXUAL SELECTION     ANDERSSON M, 1996, TRENDS ECOL EVOL, V11, P53     ARNOLD SJ, 1984, EVOLUTION, V38, P709     BERGLUND A, 1996, BIOL J LINN SOC, V58, P385     BORGIA G, 1979, SEXUAL SELECTION REP, P19     BRODIE ED, 1995, TRENDS ECOL EVOL, V10, P313     BROWN L, 1985, ANN ENTOMOL SOC AM, V78, P423     CANDOLIN U, 1999, ANIM BEHAV 6, V58, P1261     CANDOLIN U, 2000, BEHAV ECOL SOCIOBIOL, V49, P57     CANDOLIN U, 1999, P ROY SOC LOND B BIO, V266, P785     CHARLESWORTH B, 1987, SEXUAL SELECTION TES, P21     COOK D, 1988, AUST J ZOOL, V36, P521     COOK D, 1987, AUST J ZOOL, V35, P123     COOK DF, 1990, ANIM BEHAV, V40, P428     DARWIN CR, 1871, DESCENT MAN SELECTIO     DAVID P, 2000, NATURE, V406, P186     DAVID P, 1998, P ROY SOC LOND B BIO, V265, P2211     EBERHARD WG, 1982, AM NAT, V119, P420     EBERHARD WG, 1991, EVOLUTION, V45, P18     EBERHARD WG, 1987, J KANSAS ENTOMOL SOC, V60, P504     EBERHARD WG, 1979, SEXUAL SELECTION REP, P231     EMLEN DJ, 1997, BEHAV ECOL SOCIOBIOL, V41, P335     EMLEN DJ, 1994, P ROY SOC LOND B BIO, V256, P131     EMLEN ST, 1977, SCIENCE, V197, P215     ENDLER JA, 1986, NATURAL SELECTION WI     FALCONER DS, 1989, INTRO QUANTITATIVE G     FRISCHKNECHT M, 1993, EVOL ECOL, V7, P439     GRAFEN A, 1990, J THEOR BIOL, V144, P517     GRIFFITH SC, 1999, NATURE, V400, P358     HARDY ICW, 1998, ANIM BEHAV 3, V56, P787     HUNT J, 1998, BEHAV ECOL SOCIOBIOL, V42, P447     HUNT J, 1997, BEHAV ECOL SOCIOBIOL, V41, P109     HUNT J, 1999, ECOL ENTOMOL, V24, P174     HUNT J, 2000, EVOLUTION, V54, P936     HUNT J, 2002, J EVOLUTION BIOL, V15, P57     JANZEN FJ, 1998, EVOLUTION, V52, P1564     JOHNSTONE RA, 1995, BIOL REV, V70, P1     KEYSER AJ, 1999, P ROY SOC LOND B BIO, V266, P771     KIRKPATRICK M, 1982, EVOLUTION, V36, P1     KIRKPATRICK M, 1991, NATURE, V350, P33     KOKKO H, 1998, EVOL ECOL, V12, P739     KOTIAHO JS, 2001, BEHAV ECOL, V12, P553     KOTIAHO JS, 2000, BEHAV ECOL SOCIOBIOL, V48, P188     KOTIAHO JS, 2001, BIOL REV, V76, P365     KOTIAHO JS, 2001, NATURE, V410, P684     KOTIAHO JS, 1999, OIKOS, V87, P399     LANDE R, 1983, EVOLUTION, V37, P1210     MAPPES J, 1996, P ROY SOC LOND B BIO, V263, P785     MILINSKI M, 1990, NATURE, V344, P330     MOCZEK AP, 2000, ANIM BEHAV 2, V59, P459     OTRONEN M, 1988, ANIM BEHAV, V36, P741     PALMER TJ, 1978, NATURE, V274, P583     RASMUSSEN JL, 1994, J INSECT BEHAV, V7, P67     ROFF D, 1997, EVOLUTIONARY QUANTIT     ROWE L, 1996, P ROY SOC LOND B BIO, V263, P1415     SIMMONS LW, 1999, P ROY SOC LOND B BIO, V266, P145     SIVAJOTHY MT, 1987, J ETHOL, V5, P165     TAYLOR PD, 1982, THEOR POPUL BIOL, V22, P392     TOMKINS JL, 1998, ANIM BEHAV 2, V56, P347     WILKINSON GS, 1999, P ROY SOC LOND B BIO, V266, P1685     ZAHAVI A, 1977, J THEOR BIOL, V67, P603EnglishArticle619YBBEHAV ECOL},
	month = {Nov-Dec},
	pages = {791-799},
	abstract = {Sexual selection has traditionally been divided into competition over mates and mate choice. Currently, models of sexual selection predict that sexual traits are expressed in proportion to the condition of their bearer. In horned beetles, male contest competition is well established, but studies on female preferences are scarce. Here I present data on male mating success and condition dependence of courtship rate in three species of horn-dimorphic thing beetles, Onthaphagus taurus, Onthophagus binodis, and Onthophagus australis. I found that in the absence of male contest competition, mating success of O. taurus and O. australis was unrelated to their horn length and body size, whereas in O. binodis horn size had a negative effect but body size had a positive effect on male mating success. Overall, in O. binodis major morph males had greater mating success than minor morph males. In all three species male mating success was affected by courtship rate, and the Courtship rate was condition dependent such that when males were manipulated to be in poor condition they had lower courtship rates than males that were manipulated to be in good condition. My findings provide new insight into the mating systems of horned dung beetles and support an important assumption in indicator models of sexual selection.},
	keywords = {alternative reproductive, condition dependence, FEMALE CHOICE, gradient, horn dimorphism, horned dung beetles, lek, logistic regression, mating success, Onthophagus, onthophagus-acuminatus coleoptera, SELECTION, sexual selection, stalk-eyed flies, tactics},
	url = {<Go to ISI>://000179504300011},
	author = {Kotiaho, J. S.}
}
@article {2027,
	title = {Facultative paternal investment in the polyphenic beetle Onthophagus taurus; the role of male morphology and social context},
	journal = {Behavioral Ecology},
	volume = {10},
	number = {6},
	year = {1999},
	pages = {641-647},
	keywords = {beetles, facultative parental investment, honest indicators, Onthophagus, phenotypic plasticity, Polyphenism, sexual selection},
	author = {Moczek, Armin P.}
}
