Papers by Randy Thornhill
12. Selective Mate Choice by Females
Harvard University Press eBooks, Dec 31, 1983
Stress and human behavior : Attractiveness, women's sexual development, post- partum depression, and baby's cry
Advances in The Study of Behavior, 1998
Nonlinearity and the Importance of Fluctuating Asymmetry as a Predictor of Fitness
Oikos, Aug 1, 1999
... Extensive experiments have shown that asymmetry independent of size affects mat-ing success (... more ... Extensive experiments have shown that asymmetry independent of size affects mat-ing success (Moller 1992, 1993, Grammer and Thornhill 1994, Swaddle and Cuthill 1994a, b, Bennett et al. 1996, Morris 1998, Morris and Casey 1998, Schliiter et al. ...
Adaptive Female-Mimicking Behavior in a Scorpionfly
Science, Jul 27, 1979
This study provides a clear example of female-mimicking behavior by males in insects and evaluate... more This study provides a clear example of female-mimicking behavior by males in insects and evaluates quantitatively the adaptive significance of this behavior, which is poorly understood in many other organisms. Males of Hylobittacus apicalis provide females with a prey arthropod during copulation. Some males mimic female behavior when interacting with males that have captured nuptial prey, resulting in males stealing prey which they will use for copulation. Males that pirate prey copulate more frequently and probably incur fewer predation-related risks.
The Evolution of Insect Mating Systems
Evolution, May 1, 1984
All aspects of insect reproductive behaviour are discussed from a modern evolutionary viewpoint. ... more All aspects of insect reproductive behaviour are discussed from a modern evolutionary viewpoint. The topics dealt with include evolutionary hypotheses, modes of reproduction, sexual selection theory, timing of mate location, motivation to copulate, competition, defence of ...
Adaptations to Ovulation: Implications for Sexual and Social Behavior
Current Directions in Psychological Science, Dec 1, 2005
ABSTRACT In socially monogamous species in which males heavily invest in offspring, there arises ... more ABSTRACT In socially monogamous species in which males heavily invest in offspring, there arises an inevitable genetic conflict between partners over whether investing males become biological fathers of their partners' offspring. Humans are such a species. The ovulatory-shift hypothesis proposes that changes in women's mate preferences and sexual interests across the cycle are footprints of this conflict. When fertile (mid-cycle), women find masculine bodily and behavioral features particularly sexy and report increased attraction to men other than current partners. Men are more vigilant of partners when the latter are fertile, which may reflect evolved counteradaptations. This adaptationist hypothesis has already generated several fruitful research programs, but many questions remain.
Scientific Methodology in Entomology
Florida Entomologist, Mar 1, 1984
A meta-analysis of the heritability of developmental stability
Journal of Evolutionary Biology, 1997
The existence of additive genetic variance in developmental stability has important implications ... more The existence of additive genetic variance in developmental stability has important implications for our understanding of morphological variation. The heritability of individual fluctuating asymmetry and other measures of developmental stability have frequently been estimated from parent‐offspring regressions, sib analyses, or from selection experiments. Here we review by meta‐analysis published estimates of the heritability of developmental stability, mainly the degree of individual fluctuating asymmetry in morphological characters. The overall mean effect size of heritabilities of individual fluctuating asymmetry was 0.19 from 34 studies of 17 species differing highly significantly from zero (P < 0.0001). The mean heritability for 14 species was 0.27. This indicates that there is a significant additive genetic component to developmental stability. Effect size was larger for selection experiments than for studies based on parent‐offspring regression or sib analyses, implying that genetic estimates were unbiased by maternal or common environment effects. Additive genetic coefficients of variation for individual fluctuating asymmetry were considerably higher than those for character size per se. Developmental stability may be significantly heritable either because of strong directional selection, or fluctuating selection regimes which prevent populations from achieving a high degree of developmental stability to current environmental and genetic conditions.
The notal organ of the scorpionfly (<i>Panorpa vulgaris</i>): an adaptation to coerce mating duration
Behavioral Ecology, 1991
The notal organ in P. vulgaris (Insecta: Mecoptera) is a clamplike structure on the dorsum of the... more The notal organ in P. vulgaris (Insecta: Mecoptera) is a clamplike structure on the dorsum of the middle of the male&amp;#x27;s abdomen that holds one of the female&amp;#x27;s forewings throughout mating. Males often provide salivary masses as food to their mates during mating, and a male&amp;#x27;s ability to ...
The Red Queen: Sex and the Evolution of Human Nature.Matt Ridley
The Quarterly Review of Biology, Dec 1, 1994
5. Motivation to Copulate
The Study of Adaptation
Routledge eBooks, Oct 7, 2021
Biological Reviews, Jan 11, 2007
Developmental stability reflects the ability of a genotype to undergo stable development of a phe... more Developmental stability reflects the ability of a genotype to undergo stable development of a phenotype under given environmental conditions. Deviations from developmental stability arise from the disruptive effects of a wide range of environmental and genetic stresses, and such deviations are usually measured in terms of fluctuating asymmetry and phenodeviants. Fluctuating asymmetry is the most sensitive indicator of the ability to cope with stresses during ontogeny. There is considerable evidence that developmental stability, and especially fluctuating asymmetry, is a useful measure of phenotypic and genetic quality, because it covaries negatively with performance in multiple fitness domains in many species, including humans. It is proposed that developmental stability is an important marker of human health. Our goal is to initiate formally the integration of the sciences of evolutionary biology, developmental biology and medicine. We believe that this integrative framework provides a significant addition to the growing field of Darwinian medicine. The literature linking developmental stability and disease in humans is reviewed. Recent biological theoretical treatments pertaining to developmental stability are applied to a range of human health issues such as genetic diseases, ageing and survival, subfertility, abortion, child maltreatment by parents, cancer, infectious diseases, physiological and mental health, and physical attractiveness as a health certification.
Animal Behaviour, May 1, 1980
Little is known about the structure of mating aggregations of insects or sexual selection within ... more Little is known about the structure of mating aggregations of insects or sexual selection within them. Male lovebugs (Plecia nearctica) hover in large swarms above emergence sites in the ground litter. Females emerge periodically and take flight through the hovering males. Females may be grasped by one or more males before or during flight. Male-male interactions and the structure of lovebug swarms are clearly related to competition for access to emerging females. Lovebug swarms are distinctly stratified vertically: large males at the bottom nearest the ground, medium-sized males in the middle, and small males at the top farthest from the ground. Large males closest to the ground have better access to females and experience greater copulatory success.
Proceedings of The Royal Society B: Biological Sciences, Aug 17, 2005
Normally ovulating women have been found to report greater sexual attraction to men other than th... more Normally ovulating women have been found to report greater sexual attraction to men other than their own partners when near ovulation relative to the luteal phase. One interpretation is that women possess adaptations to be attracted to men possessing (ancestral) markers of genetic fitness when near ovulation, which implies that women's interests should depend on qualities of her partner. In a sample of 54 couples, we found that women whose partners had high developmental instability (high fluctuating asymmetry) had greater attraction to men other than their partners, and less attraction to their own partners, when fertile.
9. Intraspecific Variation in Male Mating Systems
Dispersal of Plecia nearctica (Diptera: Bibionidae)
Florida Entomologist, Mar 1, 1976
... Avg. No. Males, Females &amp; Prs./Trap 14.8 16.0 7.0 - - 4.3 12 4.5 ACKNOWLEDGMENTS I th... more ... Avg. No. Males, Females &amp; Prs./Trap 14.8 16.0 7.0 - - 4.3 12 4.5 ACKNOWLEDGMENTS I thankChristopher Loetscher and James V. Modica for help in the collection of some of the data. I am grateful to Louis C. Kuitert, James E. Page 9. Thornhill: Plecia neartica Dispersal 53 ...
Do Women Have Evolved Adaptation for Extra-Pair Copulation?
Springer eBooks, 2003
Do Women Have Evolved Adaptation for Extra-Pair Copulation? RANDY THORNHILL and STEVEN W. GANGEST... more Do Women Have Evolved Adaptation for Extra-Pair Copulation? RANDY THORNHILL and STEVEN W. GANGESTAD Do women have special-purpose evolved adaptation that functions in pur- suing copulations with men other than the main romantic ...
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Papers by Randy Thornhill