scholarly journals Positive feedback and alternative stable states in inbreeding, cooperation, sex roles and other evolutionary processes

2012 ◽  
Vol 367 (1586) ◽  
pp. 211-221 ◽  
Author(s):  
Jussi Lehtonen ◽  
Hanna Kokko
Keyword(s):  
Sexual Selection ◽  
Parental Care ◽  
Positive Feedback ◽  
Alternative Stable States ◽  
Operational Sex Ratio ◽  
Evolution Of Cooperation ◽  
Systems Science ◽  
Stable States ◽  
Uniparental Care ◽  
The Relationship

A large proportion of studies in systems science focus on processes involving a mixture of positive and negative feedbacks, which are also common themes in evolutionary ecology. Examples of negative feedback are density dependence (population regulation) and frequency-dependent selection (polymorphisms). Positive feedback, in turn, plays a role in Fisherian ‘runaway’ sexual selection, the evolution of cooperation, selfing and inbreeding tolerance under purging of deleterious alleles, and the evolution of sex differences in parental care. All these examples feature self-reinforcing processes where the increase in the value of a trait selects for further increases, sometimes via a coevolutionary feedback loop with another trait. Positive feedback often leads to alternative stable states (evolutionary endpoints), making the interpretation of evolutionary predictions challenging. Here, we discuss conceptual issues such as the relationship between self-reinforcing selection and disruptive selection. We also present an extension of a previous model on parental care, focusing on the relationship between the operational sex ratio and sexual selection, and the influence of this relationship on the evolution of biparental or uniparental care.

scholarly journals Sex roles, parental care and offspring growth in two contrasting coucal species

2016 ◽  
Vol 3 (10) ◽  
pp. 160463 ◽  
Author(s):  
Wolfgang Goymann ◽  
Ignas Safari ◽  
Christina Muck ◽  
Ingrid Schwabl
Keyword(s):  
Sexual Selection ◽  
Parental Care ◽  
Sex Roles ◽  
Evolutionary Ecology ◽  
Recent Theory ◽  
Uniparental Care ◽  
Trade Offs ◽  
Offspring Growth ◽  
Adult Sex Ratio

The decision to provide parental care is often associated with trade-offs, because resources allocated to parental care typically cannot be invested in self-maintenance or mating. In most animals, females provide more parental care than males, but the reason for this pattern is still debated in evolutionary ecology. To better understand sex differences in parental care and its consequences, we need to study closely related species where the sexes differ in offspring care. We investigated parental care in relation to offspring growth in two closely related coucal species that fundamentally differ in sex roles and parental care, but live in the same food-rich habitat with a benign climate and have a similar breeding phenology. Incubation patterns differed and uniparental male black coucals fed their offspring two times more often than female and male white-browed coucals combined. Also, white-browed coucals had more ‘off-times’ than male black coucals, during which they perched and preened. However, these differences in parental care were not reflected in offspring growth, probably because white-browed coucals fed their nestlings a larger proportion of frogs than insects. A food-rich habitat with a benign climate may be a necessary, but—perhaps unsurprisingly—is not a sufficient factor for the evolution of uniparental care. In combination with previous results (Goymann et al . 2015 J. Evol. Biol . 28 , 1335–1353 ( doi:10.1111/jeb.12657 )), these data suggest that white-browed coucals may cooperate in parental care, because they lack opportunities to become polygamous rather than because both parents were needed to successfully raise all offspring. Our case study supports recent theory suggesting that permissive environmental conditions in combination with a particular life history may induce sexual selection in females. A positive feedback loop among sexual selection, body size and adult sex-ratio may then stabilize reversed sex roles in competition and parental care.

scholarly journals Size Dimorphism, Intrasexual Competition, and Sexual Selection in Wattled Jacana (Jacana Jacana), A Sex-Role-Reversed Shorebird in Panama

The Auk ◽  
2004 ◽  
Vol 121 (2) ◽  
pp. 391-403 ◽  
Author(s):  
Stephen T. Emlen ◽  
Peter H. Wrege
Keyword(s):  
Sexual Selection ◽  
Parental Care ◽  
Sex Role ◽  
Intrasexual Competition ◽  
Operational Sex Ratio ◽  
Same Sex ◽  
Size Dimorphism ◽  
Future Reproduction ◽  
The Republic ◽  
Reproductive Rates

AbstractWe studied sexual size dimorphism, intrasexual competition, and sexual selection in an individually marked population of Wattled Jacanas (Jacana jacana) in the Republic of Panama. Males are the sole incubators of eggs (28-day incubation) and primary providers of chick care (50–60 days). Females were 48% heavier than, and behaviorally dominant over, males. Females also showed greater development of secondary sexual characters (fleshy facial ornamentation and wing spurs) than males. Both sexes defended territories throughout the year against same-sex conspecifics. Competition for territorial space was intense, and many individuals of both sexes did not become breeders. Resident females further competed with one another to accumulate multiple mates, resulting in a mating system of simultaneous polyandry. Female and male residents (territory holders) were larger, heavier, and more ornamented than adult floaters of the same sex. Larger and heavier females also had more mates than smaller females. Body size was thus a critical predictor of success in intrasexual competition for territories (both sexes) and for mates (females). Three measures of sexual selection—(1) sex difference in the opportunity for sexual selection, (2) female-to-male ratio of potential reproductive rates, and (3) operational sex ratio—each indicated that sexual selection is currently operating more strongly on females than on males (female-to-male ratios ranged from 1.43:1 to 2.22:1). Values of 1.61:1 and 1.43:1 represent the first published quantitative estimates of the opportunity for sexual selection for any sex-role-reversed bird. Our study supports the theory that when increased parental care entails reduced opportunities for future reproduction, asymmetries in parental care behaviors of the sexes can influence the intensity of competition for mates and the direction and strength of sexual selection.

Fire Feedbacks with Vegetation and Alternative Stable States

2009 ◽  
Vol 18 (1) ◽  
pp. 159-173 ◽  
Author(s):  
Brian Beckage ◽  
Chris Ellingwood ◽  
Keyword(s):  
Alternative Stable States ◽  
Stable States ◽  
Fire Feedbacks

scholarly journals The relationship between sexual selection and speciation

2012 ◽  
Vol 58 (3) ◽  
pp. 413-415 ◽  
Author(s):  
Maria R. Servedio
Keyword(s):  
Sexual Selection ◽  
The Relationship

Are parental care trade-offs in shorebirds driven by parental investment or sexual selection?

2009 ◽  
Vol 22 (4) ◽  
pp. 672-682 ◽  
Author(s):  
V. A. OLSON ◽  
T. J. WEBB ◽  
R. P. FRECKLETON ◽  
T. SZÉKELY
Keyword(s):  
Sexual Selection ◽  
Parental Care ◽  
Parental Investment ◽  
Trade Offs

Are systems with strong underlying abiotic regimes more likely to exhibit alternative stable states?

Oikos ◽  
2005 ◽  
Vol 110 (2) ◽  
pp. 409-416 ◽  
Author(s):  
Raphael K. Didham ◽  
Corinne H. Watts ◽  
David A. Norton
Keyword(s):  
Alternative Stable States ◽  
Stable States

scholarly journals Sexual selection favours male parental care, when females can choose

2011 ◽  
Vol 279 (1734) ◽  
pp. 1784-1790 ◽  
Author(s):  
Suzanne H. Alonzo
Keyword(s):  
Sexual Selection ◽  
Parental Care ◽  
Female Choice ◽  
Mating Success ◽  
Current Theory ◽  
Sharp Contrast ◽  
Recent Theory ◽  
Extra Pair Paternity ◽  
Female Promiscuity ◽  
Male Care

Explaining the evolution of male care has proved difficult. Recent theory predicts that female promiscuity and sexual selection on males inherently disfavour male care. In sharp contrast to these expectations, male-only care is often found in species with high extra-pair paternity and striking variation in mating success, where current theory predicts female-only care. Using a model that examines the coevolution of male care, female care and female choice; I show that inter-sexual selection can drive the evolution of male care when females are able to bias mating or paternity towards parental males. Surprisingly, female choice for parental males allows male care to evolve despite low relatedness between the male and the offspring in his care. These results imply that predicting how sexual selection affects parental care evolution will require further understanding of why females, in many species, either do not prefer or cannot favour males that provide care.

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