Journal articles: 'Positive assortative mating'

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Greenwood, Jeremy, Nezih Guner, Georgi Kocharkov, and Cezar Santos. "Marry Your Like: Assortative Mating and Income Inequality." American Economic Review 104, no. 5 (May 1, 2014): 348–53. http://dx.doi.org/10.1257/aer.104.5.348.

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Has there been an increase in positive assortative mating? Does assortative mating contribute to household income inequality? Data from the United States Census Bureau suggests there has been a rise in assortative mating. Additionally, assortative mating affects household income inequality. In particular, if matching in 2005 between husbands and wives had been random, instead of the pattern observed in the data, then the Gini coefficient would have fallen from the observed 0.43 to 0.34, so that income inequality would be smaller. Thus, assortative mating is important for income inequality. The high level of married female labor-force participation in 2005 is important for this result.

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Ólafsdóttir, Gudbjörg Á., Michael G. Ritchie, and Sigurdur S. Snorrason. "Positive assortative mating between recently described sympatric morphs of Icelandic sticklebacks." Biology Letters 2, no. 2 (March 6, 2006): 250–52. http://dx.doi.org/10.1098/rsbl.2006.0456.

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Recently, models of sympatric speciation have suggested that assortative mating can develop between sympatric morphs due to divergence in an ecologically important character. For example, in sympatric pairs of threespine stickleback ( Gasterosteus aculeatus L.) size-assortative mating seems to be instrumental in reproductive isolation. Here, we examine courtship behaviour and assortative mating of newly described sympatric stickleback morphs in Lake Thingvallavatn, Iceland. We find that the two morphs show strong positive assortative mating. However, the mechanism involved in mate choice does not seem to be as straightforward as in other similar systems of sympatric stickleback morphs and may involve variation in nest type.

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Clark, H. L., and P. R. Y. Backwell. "Assortative mating in a fiddler crab." Behaviour 153, no. 2 (2016): 175–85. http://dx.doi.org/10.1163/1568539x-00003333.

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Non-random mating, particularly positive size-assortative mating, is common and can have major evolutionary consequences. The causes of size-assortative mating, however, are rarely examined. Here we explore the possibility of sexual selection, mate availability and mating constraints causing the strong correlation between male and female sizes in the fiddler crabUca mjoebergi. We show that the full size range of males is available to females throughout the mating period, so mate availability is unlikely to cause size-assortative mating in this species. We also show that mechanical constraints do not prevent females from entering the burrows or mating with the full size range of males. We suggest that the strong size assortative mating that we observed throughout the mating cycle is driven by sexual selection. Both males and females prefer large partners. The benefit to mating with large partners needs further investigation.

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Delestrade, Anne. "Sexual Size Dimorphism and Positive Assortative Mating in Alpine Choughs (Pyrrhocorax graculus)." Auk 118, no. 2 (April 1, 2001): 553–56. http://dx.doi.org/10.1093/auk/118.2.553.

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Abstract The degree of sexual size dimorphism in a number of different morphological characters was examined in a social corvid, the Alpine Chough, using measurements taken on 178 males and 144 females. A small amount of size dimorphism appeared in all morphological characters, and weight was the most dimorphic character. To identify if Alpine Choughs mate assortatively, measurements of mates were compared in 76 pairs. A positive assortative mating was found on tarsus length, and a small positive trend is suggested between body condition of partners, but that needs to be confirmed with a larger sample size.

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Fox, S., C. N. Johnson, R. Brooks, and M. J. Lewis. "Polymorphism, mate choice and sexual selection in the Gouldian finch (Erythrura gouldiae)." Australian Journal of Zoology 50, no. 2 (2002): 125. http://dx.doi.org/10.1071/zo02002.

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Mate choice can result in both assortative mating and directional sexual selection, but few studies have addressed both processes simultaneously. Here we test several hypotheses regarding the possible role of female mate choice in maintaining the face-colour polymorphism of, and affecting directional sexual selection in, the Gouldian finch. These endangered Australian finches are highly sexually dimorphic and are genetically polymorphic for face colour: there are black-, red- and gold-faced individuals. First we showed that Gouldian finches tend to pair positive-assortatively by face colour morph in aviaries. In a laboratory experiment, we tested whether female mate choice is assortative by face colour. Overall, females neither preferred males of the same or of different face colour morphs as themselves. We found weak evidence for positive assortative female choice at one of the two loci involved in determining face colour. Next, we tested whether females showed frequency-dependent mate choice, and found that they preferred neither rare nor common male morphs. In order to test for directional sexual selection on males by female mate choice, we examined the correlations between male morphological traits and attractiveness to females. We found that tail pin length and bill size are correlated with male attractiveness, and may be under sexual selection. Thus, whilst female mate choice may be an important process in determining the evolution of male morphology, and potentially sexual dimorphism, it does not appear to be the primary force behind the assortative mating pattern among the face colour morphs.

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Class, Barbara, and Jon E. Brommer. "Shared environmental effects bias phenotypic estimates of assortative mating in a wild bird." Biology Letters 14, no. 7 (July 2018): 20180106. http://dx.doi.org/10.1098/rsbl.2018.0106.

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Assortative mating is pervasive in wild populations and commonly described as a positive correlation between the phenotypes of males and females across mated pairs. This correlation is often assumed to reflect non-random mate choice based on phenotypic similarity. However, phenotypic resemblance between mates can also arise when their traits respond plastically to a shared environmental effect creating a (within-pair) residual correlation in traits. Using long-term data collected in pairs of wild blue tits and a covariance partitioning approach, we empirically demonstrate that such residual covariance indeed exists and can generate phenotypic correlations (or mask assortative mating) in behavioural and morphometric traits. These findings (i) imply that residual covariance is likely to be common and bias phenotypic estimates of assortative mating, which can have consequences for evolutionary predictions, (ii) call for the use of rigorous statistical approaches in the study of assortative mating, and (iii) show the applicability of one of these approaches in a common study system.

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González, Fernando Antonio Ignacio, and Juan Antonio Dip. "The Impact of Educational Assortative Mating on Income Inequality: Evidence from Argentina." Journal of Population and Social Studies 30 (November 10, 2021): 116–27. http://dx.doi.org/10.25133/jpssv302022.008.

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This paper seeks to quantify the impact of educational assortative mating on income inequality among households in Argentina. We use microdata from two household surveys conducted by the National Institute of Statistics and Census: The Permanent Household Survey and the National Survey of Risk Factors. We construct contingency tables and perform a regression analysis to study the existence of educational assortative mating. We also present counterfactual simulations of random re-matching of observations. The results show that a sizeable proportion of couples are educationally homogamous (45%). Comparing the Gini coefficients calculated in the real matching and the simulated scenarios, we observe a reduction of up to 4 points. Thus, the educational assortative mating represents a relevant dimension to explain income inequality. Our results recommend considering this matching pattern when defining optimal income taxes; this is, if there is a high positive covariance between the income of both members of the couple, it seems appropriate, from a redistributive point of view, to define income taxes at the household level and not at the individual level (as is currently the case in most countries, including Argentina).

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Kramarenko, S. S., and A. S. Kramarenko. "On Mate Choice in two Xerophilic Species of Land Snails, Brephulopsis cylindrica (Pulmonata, Enidae) and Xeropicta derbentina (Pulmonata, Hygromiidae)." Vestnik Zoologii 53, no. 3 (June 1, 2019): 237–44. http://dx.doi.org/10.2478/vzoo-2019-0023.

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Abstract The cases of assortative mating are known in varied species of Gastropoda, however it is unclear how widely distributed this reproductive strategy is across the class. The data concerning land snails (Stylommatophora) are especially contradictory. By using two model species of stylommatophoran mollusks, Brephulopsis cylindrica (Menke, 1828) and Xeropicta derbentina (Krynicki, 1836), we conducted a long-term observation of their copulatory behavior in Southern Ukraine. In X. derbentina, a clear pattern of the positive assortative mating with respect to body size was found, whereas assortative mating in relation to shell banding polymorphism was revealed in 2 cases out of 7. B. cylindrica snails copulate with any available mate partner, regardless of its size.

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Räsänen, Katja, Matthieu Delcourt, Lauren J. Chapman, and Andrew P. Hendry. "Divergent Selection and Then What Not: The Conundrum of Missing Reproductive Isolation in Misty Lake and Stream Stickleback." International Journal of Ecology 2012 (2012): 1–14. http://dx.doi.org/10.1155/2012/902438.

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In ecological speciation, reproductive isolation evolves as a consequence of adaptation to different selective environments. A frequent contributor to this process is the evolution of positive assortative mate choice between ecotypes. We tested this expectation for lake and inlet stream threespine stickleback (Gasterosteus aculeatus) from the Misty system (Vancouver Island, Canada), which show strong genetically based adaptive divergence and little genetic exchange in nature. This, and work on other stickleback systems, led us to expect positive assortative mating. Yet, our standard “no-choice” laboratory experiment on common-garden fish revealed no evidence for this—despite divergence in traits typically mediating assortative mating in stickleback. These results remind us that divergent natural selection may not inevitably lead to the evolution of positive assortative mate choice. The apparent lack of strong and symmetric reproductive barriers in this system presents a conundrum: why are such barriers not evident despite strong adaptive divergence and low gene flow in nature?

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Yu, Tong Lei, Yao Hui Deng, Juan Zhang, and Li Peng Duan. "Size-assortative copulation in the simultaneously hermaphroditic pond snail Radix auricularia (Gastropoda: Pulmonata)." Animal Biology 66, no. 3-4 (2016): 239–47. http://dx.doi.org/10.1163/15707563-00002501.

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To better understand the importance of body size in hermaphroditic mating, we studied the mating behaviour of the pond snail Radix auricularia. This simultaneous hermaphrodite exhibits a positive correlation between body size and egg production and provides weak evidence for size-assortative mating. In addition to this mating pattern, the partner performing the male role was significantly smaller than the mounted partner, performing the female role. In this study, two laboratory experiments were done to test whether body size has (1) an effect on mate choice of the sperm donor, and (2) poses mechanical constraints. These snails did not display physical limitation in mating with a much larger or smaller partner. In the mate choice experiment, we found no evidence for significant preferences for large partners. Therefore, mate choice of sperm donor and mechanical constraints are not likely to contribute to the formation of size-assortatively mating pairs in this species, which contributes to understanding about how these processes work in hermaphrodites.

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Sharp, Nathaniel P., and Michael C. Whitlock. "No evidence of positive assortative mating for genetic quality in fruit flies." Proceedings of the Royal Society B: Biological Sciences 286, no. 1912 (October 2, 2019): 20191474. http://dx.doi.org/10.1098/rspb.2019.1474.

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In sexual populations, the effectiveness of selection will depend on how gametes combine with respect to genetic quality. If gametes with deleterious alleles are likely to combine with one another, deleterious genetic variation can be more easily purged by selection. Assortative mating, where there is a positive correlation between parents in a phenotype of interest such as body size, is often observed in nature, but does not necessarily reveal how gametes ultimately combine with respect to genetic quality itself. We manipulated genetic quality in fruit fly populations using an inbreeding scheme designed to provide an unbiased measure of mating patterns. While inbred flies had substantially reduced reproductive success, their gametes did not combine with those of other inbred flies more often than expected by chance, indicating a lack of positive assortative mating. Instead, we detected a negative correlation in genetic quality between parents, i.e. disassortative mating, which diminished with age. This pattern is expected to reduce the genetic variance for fitness, diminishing the effectiveness of selection. We discuss how mechanisms of sexual selection could produce a pattern of disassortative mating. Our study highlights that sexual selection has the potential to either increase or decrease genetic load.

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Banerjee, Sarla. "Assortative mating for colour in Indian populations." Journal of Biosocial Science 17, no. 2 (April 1985): 205–9. http://dx.doi.org/10.1017/s0021932000015650.

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SummarySkin colour is measured at the inner upper arm and forehead by reflectance spectrophotometry in 310 Punjabi Hindu spouse pairs. It suggests genetic similarity of the two subcastes Khatri and Arora, of Punjabi Hindus, and that caste formation is essentially a social phenomenon. There is evidence of positive assortative mating with respect to skin colour.

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James, W. H. "Assortative mating for height in Pakistani arranged marriages—." Journal of Biosocial Science 18, no. 2 (April 1986): 247–48. http://dx.doi.org/10.1017/s0021932000016163.

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Ahmad, Gilbert & Naqui (1985) note that there is a substantial and significant positive correlation between the heights of spouses in Pakistani arranged marriages. This was so even in those cases where the spouses had not seen one another before the ceremony. They offer three possible explanations. I should like to suggest another.

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Thomas, F., C. Liautard, F. Cézilly, and F. Renaud. "A finite time horizon influences sequential mate choice in male Gammarus aequicauda (Amphipoda)." Canadian Journal of Zoology 76, no. 3 (March 1, 1998): 400–404. http://dx.doi.org/10.1139/z97-211.

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Although size-assortative pairing has been extensively studied in amphipods, the influence of time left to moult (TLM) on pairing decisions of male gammarids remains largely unexplored. Given that moulting males cannot guard their mates, we investigated the influence of TLM for males on size-assortative mating in the gammarid Gammarus aequicauda (Crustacea, Amphipoda). There was a significant relationship between TLM and size in males. Unpaired males were closer to their moult than paired ones. Among pairs, there was a significant positive relationship between male and female sizes and between male and female TLM values. However, males closer to the moult were paired with females of more varying sizes than were other males, suggesting that a decrease in TLM reduces choosiness in males. Although there was a significant relationship between TLM and size in males, size-assortative mating was independent of male TLM.

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Haas, Fredrik, Jonas Knape, and Anders Brodin. "Habitat preferences and positive assortative mating in an avian hybrid zone." Journal of Avian Biology 41, no. 3 (June 22, 2010): 237–47. http://dx.doi.org/10.1111/j.1600-048x.2009.04788.x.

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Lstibůrek, M., T. J. Mullin, D. Lindgren, and O. Rosvall. "Open-nucleus breeding strategies compared with population-wide positive assortative mating." Theoretical and Applied Genetics 109, no. 6 (July 29, 2004): 1169–77. http://dx.doi.org/10.1007/s00122-004-1737-2.

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Lstibůrek, M., T. J. Mullin, D. Lindgren, and O. Rosvall. "Open-nucleus breeding strategies compared with population-wide positive assortative mating." Theoretical and Applied Genetics 109, no. 6 (July 23, 2004): 1196–203. http://dx.doi.org/10.1007/s00122-004-1746-1.

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Ingram, Travis, Yuexin Jiang, Racine Rangel, and Daniel I. Bolnick. "Widespread positive but weak assortative mating by diet within stickleback populations." Ecology and Evolution 5, no. 16 (July 22, 2015): 3352–63. http://dx.doi.org/10.1002/ece3.1609.

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Singh, Bashisth N., and Sujata Chatterjee. "Symmetrical and asymmetrical sexual isolation among laboratory strains of Drosophila ananassae." Canadian Journal of Genetics and Cytology 27, no. 4 (August 1, 1985): 405–9. http://dx.doi.org/10.1139/g85-060.

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Male-choice experiments using five isofemale lines of Drosophila ananassae originating from different localities were performed to study sexual isolation within the species. In most of the crosses homogamic matings outnumber heterogamic ones, and deviation from randomness is statistically significant in 11 of 20 crosses. This provides evidence for positive assortative mating within D. ananassae. Isolation indices range from −0.057 to 0.555. Eleven positive isolation indices are significantly greater than zero. Both types of sexual isolation, symmetrical and asymmetrical, have been observed among different strains. Thus the present results clearly indicate that the laboratory strains of D. ananassae have developed behavioural reproductive isolation as a result of genetic divergence.Key words: Drosophila, assortive mating, sexual selection, behaviour.

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Harmsen, R., and L. R. McKay. "Nonrandom mate choice by females of Drosophila pseudoobscura: a case of outbreeding avoidance?" Canadian Journal of Zoology 63, no. 2 (February 1, 1985): 334–39. http://dx.doi.org/10.1139/z85-051.

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Relative mating success of genetically different males of Drosophila pseudoobscura was measured with five female strains using an experimental set-up consisting of a mating chamber containing 20 females of one strain and a total of 20 males of two different strains. No evidence was found indicating negative assortative mating, neither of the direct type, nor of the "rare male" type. Some strains, however, displayed strong positive assortative mating, as males of the same strain as the females were significantly more successful in obtaining copulations than were males of another strain present in the mating chambers. Deviations from random mating can be interpreted as the result of some males possessing higher levels of "vigour," but an alternative explanation is favoured, one involving female choice. Experimental results do indicate that the orange-eyed mutant flies, used as one of the male strains in all experiments, did have a relatively low level of courtship vigour, but not low enough to account for more than a small fraction of the differential mating success observed in some of the experiments.

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Cardoso, Ricardo Silva, Diogo Silva Costa, and Viviane Fernandes Loureiro. "Mating behaviour of the marine snail Littoraria flava (Mollusca:Caenogastropoda) on a boulder shore of south-east Brazil." Journal of the Marine Biological Association of the United Kingdom 87, no. 4 (July 30, 2007): 947–52. http://dx.doi.org/10.1017/s0025315407053210.

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The mating pattern of Littoraria flava, a typical grazer snail of the supralittoral zone and sometimes the midlittoral zone of boulder shores in tropical and sub-tropical regions, was examined to determine the occurrence of size-assortative mating and sexual selection on size. We also evaluated its reproductive behavioural mechanisms, as well as their implications for the evolution of the species. The population was investigated from May 2001 through April 2002, on an artificial rocky shore composed of a boulder wall at Flexeira Beach, Itacuruçá Island, Rio de Janeiro, Brazil (22°56′S 43°53′W). The current study showed that: (1) copulating pairs were observed only from November through March, indicating seasonal reproduction of the population; (2) linear correlation between sizes of copulating mates were weak but significant, characterizing assortative mating by size; (3) there was sexual selection for female size, i.e. large females were favoured as mating partners over small ones; however, sexual selection on size was not observed among males; (4) there were significant positive correlations between male and female shell sizes and the copulation time; (5) there were significant differences in copulation time among different types of copulating pairs; and (6) mating females were significantly larger than non-mating females, while there were no differences between the sizes of mating and non-mating males, indicating differential sexual selection between sexes. These findings may contribute to the evolution of sexual dimorphism in this species. Male choice behaviour plausibly explains the assortative mating and sexual selection on female size of Littoraria flava. As males chose larger mates because they benefit reproductively therefore large females have increased chances of mating and fertilization (sexual selection for size). Further evidence suggests that large females are more successful than small females in carrying out mating, because large females remain in copulation for a longer time than do small females.

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KARDUM, IGOR, JASNA HUDEK-KNEZEVIC, DAVID P. SCHMITT, and MELANE COVIC. "Assortative mating for Dark Triad: Evidence of positive, initial, and active assortment." Personal Relationships 24, no. 1 (November 28, 2016): 75–83. http://dx.doi.org/10.1111/pere.12168.

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Gouesnard, Brigitte, and André Gallais. "Genetic Variance Component Estimation in a Nested Mating Design with Positive Assortative Mating, and Application to Maize." Crop Science 32, no. 5 (September 1992): 1127–31. http://dx.doi.org/10.2135/cropsci1992.0011183x003200050011x.

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Castro, Mariana, João Loureiro, Brian C. Husband, and Sílvia Castro. "The role of multiple reproductive barriers: strong post-pollination interactions govern cytotype isolation in a tetraploid–octoploid contact zone." Annals of Botany 126, no. 6 (April 30, 2020): 991–1003. http://dx.doi.org/10.1093/aob/mcaa084.

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Abstract Background and Aims Polyploidy is an important contributor to sympatric speciation and assortative mating is a key mechanism driving cytotype interactions in contact zones. While strong reproductive barriers can mediate the coexistence of different cytotypes in sympatry, positive frequency-dependent mating disadvantage ultimately drives the transition to single-ploidy populations. However, comprehensive estimates of reproductive isolation among cytotypes and across multiple barriers are rare. We quantify the strength of isolation across multiple reproductive stages in a tetraploid–octoploid contact zone to understand the potential for coexistence. Methods Assortative mating due to flowering asynchrony, pollinator behaviour, morphological overlap, self-fertilization and gametic competition between tetraploid and octoploid Gladiolus communis in a contact zone in the Western Iberian Peninsula were assessed in natural and experimental populations to quantify reproductive isolation (RI) between cytotypes. Key Results Tetraploids and octoploids have a high degree of overlap in flowering time and similar floral morphology, and are visited by generalist insects without cytotype foraging preferences, resulting in weak pre-pollination RI (from 0.00 to 0.21). In contrast, post-pollination isolation resulting from gametic selection was a strong barrier to inter-cytotype mating, with ploidy composition in stigmatic pollen loads determining the levels of RI (from 0.54 to 1.00). Between-cytotype cross-incompatibility was relatively high (RI from 0.54 to 0.63) as was isolation acquired through self-pollination (RI of 0.59 in tetraploids and 0.39 in octoploids). Conclusions Total RI was high for both tetraploids (from 0.90 to 1.00) and octoploids (from 0.78 to 0.98). Such high rates of assortative mating will enable cytotype coexistence in mixed-ploidy populations by weakening the impacts of minority cytotype exclusion. This study reveals the key role of gametic selection in cytotype siring success and highlights the importance of comprehensive estimates across multiple reproductive barriers to understand cytotype interactions at contact zones.

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Petersen, Bruce C. "An economic model and evidence of the evolution of human intelligence in the Middle Pleistocene: Climate change and assortative mating." PLOS ONE 18, no. 8 (August 2, 2023): e0287964. http://dx.doi.org/10.1371/journal.pone.0287964.

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A main objective of this paper is to provide the first model of how climate change, working through sexual selection, could have led to dramatic increases in hominin brain size, and presumably intelligence, in the Middle Pleistocene. The model is built using core elements from the field of family economics, including assortative mating and specialization and complementarities between mates. The main assumptions are that family public goods (e.g., conversation, shelter, fire) were particularly cognitively intensive to produce and became increasingly important for child survival during glacial phases. Intermediate climates (e.g., not the depths of severe glacial phases) create the largest gains from specialization, encouraging negative assortative mating. In contrast, severe glacial phases encourage positive assortative mating because of the rising importance of family public goods. One testable hypothesis is that absence of severe glacial phases should have led to stasis in brain size. Two other testable hypotheses are that severe glacial phases should have led to speciation events, as well as increases in brain size. The evidence shows that there was a million-year stasis in cranial size prior to the start of the severe glacial phases. This stasis is broken by a speciation event (Homo heidelbergensis), with the oldest fossil evidence dated near the close of the first severe glacial phase. In the next 300 kyr, there are two additional severe glacial phases, accompanied by considerable increases in cranial capacity. The last speciation event is Homo sapiens, with the earliest fossils dated near the end of the last of these two glacial phases.

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Hoffmann, Lelanie, Kelvin L. Hull, Anandi Bierman, Rozane Badenhorst, Aletta E. Bester-van der Merwe, and Clint Rhode. "Patterns of Genetic Diversity and Mating Systems in a Mass-Reared Black Soldier Fly Colony." Insects 12, no. 6 (May 21, 2021): 480. http://dx.doi.org/10.3390/insects12060480.

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The black soldier fly (BSF), Hermetia illucens, is a promising candidate for the emerging insect farming industry with favourable characteristics for both bioremediation and production of animal delivered nutritive and industrial compounds. The genetic management of commercial colonies will become increasingly important for the sustainability of the industry. However, r-selected life history traits of insects pose challenges to conventional animal husbandry and breeding approaches. In this study, the long-term genetic effects of mass-rearing were evaluated as well as mating systems in the species to establish factors that might influence genetic diversity, and by implication fitness and productivity in commercial colonies. Population genetic parameters, based on microsatellite markers, were estimated and compared amongst two temporal wild sampling populations and four generations (F28, F48, F52, and F62) of a mass-reared colony. Furthermore, genetic relationships amongst mate pairs were evaluated and parentage analysis was performed to determine the oc-currence of preferential mate choice and multiple paternity. The mass-reared colony showed a reduction in genetic diversity and evidence for inbreeding with significant successive generational genetic differentiation from the wild progenitor population. Population-level analysis also gave the first tentative evidence of positive assortative mating and genetic polyandry in BSF. The homoge-neity of the mass-reared colony seems to result from a dual action caused by small effective popu-lation size and increased homozygosity due to positive assortative mating. However, the high ge-netic diversity in the wild and a polyandrous mating system might suggest the possible restoration of diversity in mass-reared colonies through augmentation with the wild population.

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Lstibůrek, M., T. J. Mullin, T. F. C. Mackay, D. Huber, and B. Li. "Positive Assortative Mating With Family Size as a Function of Predicted Parental Breeding Values." Genetics 171, no. 3 (June 18, 2005): 1311–20. http://dx.doi.org/10.1534/genetics.105.041723.

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Ináncsi, Tamás, András Láng, and Tamás Bereczkei. "A darker shade of love: Machiavellianism and positive assortative mating based on romantic ideals." Europe’s Journal of Psychology 12, no. 1 (February 29, 2016): 137–52. http://dx.doi.org/10.5964/ejop.v12i1.1007.

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Machiavellianism is a personality trait that is characterized by manipulative and exploitative attitude toward others, lack of empathy, and a cynical view of human nature. In itself or as part of the Dark Triad it has been the target of several studies investigating romantic relations. Nevertheless, the relationship between Machiavellianism and romantic ideals has not been revealed yet. An undergraduate sample of 143 (92 females) with an average age of 19.83 years (SD = 1.51 years) filled out self-report measures of Machiavellianism (Mach-IV Scale) and romantic ideals (Ideal Standards Scale and NEO-FFI-IDEAL). According to our results, Machiavellianism correlated negatively with the importance of partner’s warmth-trustworthiness, extraversion, openness, agreeableness, and with the importance of intimacy and loyalty in their ideal relationships. Machiavellianism correlated positively with the ideal partner’s possession over status and resources. Explorative factor analysis revealed three components of ideal partner’s characteristics. Machiavellianism loaded significantly on two out of three components. Results are discussed with regard to Ideal Standards Model and the Big Five model of personality.

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Hayes, B., R. K. Shepherd, and S. Newman. "Look ahead mate selection schemes for multi-breed beef populations." Animal Science 74, no. 1 (February 2002): 13–23. http://dx.doi.org/10.1017/s1357729800052206.

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AbstractLook ahead mate selection (LAMS) schemes have been proposed to improve longer-term genetic merit when both selection and crossbreeding are important. We investigate the performance of a LAMS scheme which includes both predicted progeny merit and predicted grandprogeny merit in a mate selection index (MSI). Simulation of a multi-breed beef population, with additive breeding values, direct and maternal breed effects and direct and maternal heterosis was used to compare response from the LAMS scheme to mate selection on progeny merit only (PROG), selection on estimated breeding value (EBV) followed by random mating (RAND) and a structured crossbreeding scheme (CROSS). An additional strategy, LAMS + CO, was similar to LAMS but included a negative weighting on the coancestry of selected animals in the MSI to reduce inbreeding. LAMS gave up to 3% greater response in generation eight than PROG, 4·5% greater response than RAND, and 15% greater response than CROSS. Results from LAMS + CO were very similar to LAMS but inbreeding was 11% less from LAMS + CO at generation eight. The advantage of LAMS and LAMS + CO over PROG in later generations was hypothesized to be the result of positive assortative mating and greater use of maternal effects. Evidence to support the hypothesis of assortative mating was a positive significant correlation of EBVs of mates (sires and dams) in LAMS and LAMS + CO but not in PROG. Strategies PROG, LAMS and LAMS + CO all created closed populations of animals with optimum composite breed proportions.

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Trachtenberg, Anete, A. E. Stark, F. M. Salzano, and F. J. Da Rocha. "Canonical correlation analysis of assortative mating in two groups of Brazilians." Journal of Biosocial Science 17, no. 4 (October 1985): 389–403. http://dx.doi.org/10.1017/s0021932000015911.

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SummaryIn two groups of people, 98 couples in which the husband was a military serviceman and 63 couples of Jewish ancestry living in Porto Alegre, Brazil, age at marriage, age at time of survey, fifteen anthropometric variables, and hair and eye colour were studied. Proper adjustments of the data were made taking into consideration duration of cohabitation, aging and secular effects, and skewness in the distributions. There are some differences between the two groups in age at marriage, but in both there is a tendency for those currently older to have married later in life. The correlation coefficients between spouses are with very few exceptions positive, with no indication of preferences for opposites. Size and factors related to body build are the most readily detectable agents in the assortative mating occurring in this population, but in the military group relative lengths of leg and trunk, rather than stature itself, are important in conditioning mate choice.

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Ng, Terence P. T., Gray A. Williams, Mark S. Davies, Richard Stafford, and Emilio Rolán-Alvarez. "Sampling scale can cause bias in positive assortative mating estimates: evidence from two intertidal snails." Biological Journal of the Linnean Society 119, no. 2 (June 18, 2016): 414–19. http://dx.doi.org/10.1111/bij.12839.

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Groothuis, Peter, and Paul E. Gabriel. "Positive assortative mating and spouses as complementary factors of production: a theory of labour augmentation." Applied Economics 42, no. 9 (April 2010): 1101–11. http://dx.doi.org/10.1080/00036840701721141.

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Kemp, R. A., B. W. Kennedy, and J. W. Wilton. "The effect of positive assortative mating on genetic parameters in a simulated beef cattle population." Theoretical and Applied Genetics 72, no. 1 (April 1986): 76–79. http://dx.doi.org/10.1007/bf00261458.

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Zworykin, D. D. "Mate choice and size-assortative mating in the climbing perch Anabas testudineus (Actinopteri: Anabantidae)." Vestnik Moskovskogo universiteta. Seria 16. Biologia 77, no. 4 (January 14, 2023): 224–30. http://dx.doi.org/10.55959/msu0137-0952-16-2022-77-4-224-230.

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Non-random mating plays a key role in speciation and impacts the individual life history. Body size is one of the most important traits by which the mate choice is carried out. Various patterns of body size preference are known in fi sh, but this component of reproductive strategy has been studied in a limited number of species. Although the climbing perch (Anabas testudineus) is widespread and well-known, few descriptions of its spawning have been published, only in captivity and in most cases artifi cially induced with hormonal agents. This paper describes the main features of natural spawning of the climbing perch in aquarium compared to induced spawning. A positive size-assortative mating has been revealed. The mating system of these fish has been shown to be fl exible, presumably ranging from monogamy to polygamy. The results are discussed in the context of the general issue of the adequacy of fi sh behaviour research methods.

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Carter, P. A., and W. B. Watt. "Adaptation at specific loci. V. Metabolically adjacent enzyme loci may have very distinct experiences of selective pressures." Genetics 119, no. 4 (August 1, 1988): 913–24. http://dx.doi.org/10.1093/genetics/119.4.913.

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Abstract The polymorphic phosphoglucomutase (PGM) and glucose-6-phosphate dehydrogenase (G6PD) loci have been studied in parallel to experimental work on the phosphoglucose isomerase (PGI) polymorphism in Colias butterflies. PGI, PGM and G6PD are also autosomal in Colias. PGM and G6PD are loosely linked (and represent the first identified autosomal linkage group in Colias); they assort independently from PGI. Recombination occurs in both sexes. Neither PGM nor G6PD shows large, consistent differences in flight capacity through the day among its genotypes, as PGI does. PGM shows some change of allele frequencies, and match to Hardy-Weinberg expectation, with air temperature in middle and latter parts of the season, but not early in the season. G6PD may show some heterozygote excess over Hardy-Weinberg expectation early in the day, but more testing is needed. No evidence for differential survivorship was seen at PGM or G6PD, in contrast to PGI. At the PGM and G6PD loci, male heterozygotes are advantaged in mating with females, but without the evidence of female choice which occurs for PGI. These effects are not correlated among the three loci. There is no assortative mating at G6PD (nor at PGI). There is minor positive assortative mating of PGM heterozygotes, but it is too weak to account for the PGM-genotype-specific male mating advantage. No trends of multilocus genotype frequencies involving PGI are seen. Certain PGM-G6PD two-locus genotypes are over-represented, and others under-represented, in wild adult samples, particularly among males and uniformly among successfully mating males. Our results emphasize that enzyme loci sharing a substrate need not have common experience of the existence or strength of natural selection, and suggest initial food-resource processing and allocation as a possible context for fitness-related effects of the PGM and G6PD polymorphisms.

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Kemp, R. A., and J. W. Wilton. "The effects of positive assortative mating and preferential progeny treatment on the estimation of breeding values1." Journal of Animal Breeding and Genetics 104, no. 1-5 (January 12, 1987): 251–61. http://dx.doi.org/10.1111/j.1439-0388.1987.tb00132.x.

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Peterson, Elizabeth K., Roman Yukilevich, Joanne Kehlbeck, Kelly M. LaRue, Kyle Ferraiolo, Kurt Hollocher, Helmut V. B. Hirsch, and Bernard Possidente. "Asymmetrical positive assortative mating induced by developmental lead (Pb2+) exposure in a model system, Drosophila melanogaster." Current Zoology 63, no. 2 (March 13, 2017): 195–203. http://dx.doi.org/10.1093/cz/zox016.

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Tryjanowski, Piotr, and Jaroslav Šimek. "Sexual size dimorphism and positive assortative mating in red-backed shrike Lanius collurio: an adaptive value?" Journal of Ethology 23, no. 2 (February 5, 2005): 161–65. http://dx.doi.org/10.1007/s10164-004-0142-2.

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Kollamparambil, Umakrishnan. "Educational Homogamy, Positive Assortative Mating and Income Inequality in South Africa: An Unconditional Quantile Regression Analysis." Journal of Development Studies 56, no. 9 (December 26, 2019): 1706–24. http://dx.doi.org/10.1080/00220388.2019.1696957.

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Minică, Camelia C., Dorret I. Boomsma, Conor V. Dolan, Eco de Geus, and Michael C. Neale. "Empirical comparisons of multiple Mendelian randomization approaches in the presence of assortative mating." International Journal of Epidemiology 49, no. 4 (March 10, 2020): 1185–93. http://dx.doi.org/10.1093/ije/dyaa013.

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Abstract Background Mendelian randomization (MR) is widely used to unravel causal relationships in epidemiological studies. Whereas multiple MR methods have been developed to control for bias due to horizontal pleiotropy, their performance in the presence of other sources of bias, like non-random mating, has been mostly evaluated using simulated data. Empirical comparisons of MR estimators in such scenarios have yet to be conducted. Pleiotropy and non-random mating have been shown to account equally for the genetic correlation between height and educational attainment. Previous studies probing the causal nature of this association have produced conflicting results. Methods We estimated the causal effect of height on educational attainment in various MR models, including the MR-Egger and the MR-Direction of Causation (MR-DoC) models that correct for, or explicitly model, horizontal pleiotropy. Results We reproduced the weak but positive association between height and education in the Netherlands Twin Register sample (P= 3.9 × 10–6). All MR analyses suggested that height has a robust, albeit small, causal effect on education. We showed via simulations that potential assortment for height and education had no effect on the causal parameter in the MR-DoC model. With the pleiotropic effect freely estimated, MR-DoC yielded a null finding. Conclusions Non-random mating may have a bearing on the results of MR studies based on unrelated individuals. Family data enable tests of causal relationships to be conducted more rigorously, and are recommended to triangulate results of MR studies assessing pairs of traits leading to non-random mate selection.

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Kardum, Igor, Jasna Hudek-Knezevic, Asmir Gračanin, and Nermina Mehic. "Assortative Mating for Psychopathy Components and its Effects on the Relationship Quality in Intimate Partners." Psihologijske teme 26, no. 1 (2017): 211–39. http://dx.doi.org/10.31820/pt.26.1.10.

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In three studies, we examined assortative mating for psychopathy components as well as its effects on the relationship quality in intimate partners. Compared to the original structure we confirmed three factors of psychopathy: criminal tendencies (CT), erratic lifestyle (ELS) and interpersonal manipulation (IM), while callous affect (CA) was not replicated. Hypotheses regarding positive versus negative assortment, initial assortment versus convergence, and active assortment versus social homogamy were tested. All hypotheses were examined using both variable-centered approach (VCA) and couple-centered approach (CCA). We found moderate positive assortment between intimate partners in psychopathy as a latent construct estimated by structural modelling. Furthermore, positive assortment for all three components of psychopathy was found either by using only VCA (CT), only CCA (IM) or both approaches (ELS). Additionally, initial assortment rather than convergence hypothesis and active assortment rather than social homogamy hypothesis was confirmed for all three psychopathy components, with a slight tendency towards divergence and social homogamy. We explored the effects of similarity in psychopathy components on the women and men' relationship quality by using profile similarity and polynomial regression analyses. Profile similarity in IM was significantly positively related to women's relationship quality, while the results of the polynomial regression analyses were more complex, and showed that only (dis)similarity in CT did not exert any effect on women and men's relationship quality. Greater disagreement between women and men's ELS was related with more sharp decrease of women's relationship quality, while men's relationship quality decreased at the higher levels of women and men's ELS. Greater disagreement between women and men's IM results in a lower women's relationship quality, while women and men's relationship quality was higher when women's IM was higher than men's.

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Merrill, Richard M., Richard W. R. Wallbank, Vanessa Bull, Patricio C. A. Salazar, James Mallet, Martin Stevens, and Chris D. Jiggins. "Disruptive ecological selection on a mating cue." Proceedings of the Royal Society B: Biological Sciences 279, no. 1749 (October 17, 2012): 4907–13. http://dx.doi.org/10.1098/rspb.2012.1968.

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Adaptation to divergent ecological niches can result in speciation. Traits subject to disruptive selection that also contribute to non-random mating will facilitate speciation with gene flow. Such ‘magic’ or ‘multiple-effect’ traits may be widespread and important for generating biodiversity, but strong empirical evidence is still lacking. Although there is evidence that putative ecological traits are indeed involved in assortative mating, evidence that these same traits are under divergent selection is considerably weaker. Heliconius butterfly wing patterns are subject to positive frequency-dependent selection by predators, owing to aposematism and Müllerian mimicry, and divergent colour patterns are used by closely related species to recognize potential mates. The amenability of colour patterns to experimental manipulation, independent of other traits, presents an excellent opportunity to test their role during speciation. We conducted field experiments with artificial butterflies, designed to match natural butterflies with respect to avian vision. These were complemented with enclosure trials with live birds and real butterflies. Our experiments showed that hybrid colour-pattern phenotypes are attacked more frequently than parental forms. For the first time, we demonstrate disruptive ecological selection on a trait that also acts as a mating cue.

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Kay, Cameron S. "Negative traits, positive assortment: Revisiting the Dark Triad and a preference for similar others." Journal of Social and Personal Relationships 38, no. 4 (February 2, 2021): 1259–78. http://dx.doi.org/10.1177/0265407521989820.

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Across two studies ( NTOTAL = 933), a person’s willingness to engage in a relationship with those scoring high in each of the Dark Triad traits (i.e., Machiavellianism, narcissism, and psychopathy) was examined as a function of their own levels of the Dark Triad traits and the relationship type in question (i.e., a one-night stand, a dating relationship, or a marriage). There were three notable findings. First, those scoring high in Machiavellianism, narcissism, and psychopathy were more willing to engage in a relationship with a person who was also high in Machiavellianism, narcissism, and psychopathy, respectively. Second, as the commitment level of the relationship increased, so did a narcissistic individual’s willingness to engage in a relationship with a fellow narcissist. Third, psychopathic people were generally interested in having one-night stands, seemingly without concern for the personality traits of the other person involved. Results are discussed in relation to assortative mating.

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Greenwood, Jeremy, Nezih Guner, and Guillaume Vandenbroucke. "Family Economics Writ Large." Journal of Economic Literature 55, no. 4 (December 1, 2017): 1346–434. http://dx.doi.org/10.1257/jel.20161287.

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Powerful currents have reshaped the structure of families over the last century. There has been (1) a dramatic drop in fertility and greater parental investment in children; (2) a rise in married female labor-force participation; (3) a significant decline in marriage; (4) a higher degree of positive assortative mating; (5) more children living with a single mother; and (6) shifts in social norms governing premarital sex and married women’s roles in the workplace. Macroeconomic models explaining these aggregate trends are surveyed. The relentless flow of technological progress and its role in shaping family life are stressed. (JEL D13, J12, J13, J16, J22, O33, Z13)

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Leftwich, Philip T., Naomi V. E. Clarke, Matthew I. Hutchings, and Tracey Chapman. "Gut microbiomes and reproductive isolation in Drosophila." Proceedings of the National Academy of Sciences 114, no. 48 (November 6, 2017): 12767–72. http://dx.doi.org/10.1073/pnas.1708345114.

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Experimental studies of the evolution of reproductive isolation (RI) in real time are a powerful way in which to reveal fundamental, early processes that initiate divergence. In a classic speciation experiment, populations of Drosophila pseudoobscura were subjected to divergent dietary selection and evolved significant positive assortative mating by diet. More recently, a direct role for the gut microbiome in determining this type of RI in Drosophila melanogaster has been proposed. Manipulation of the diet, and hence the gut microbiome, was reported to result in immediate assortative mating by diet, which could be eliminated by reducing gut microbes using antibiotics and recreated by adding back Lactobacillus plantarum. We suggest that the evolutionary significance of this result is unclear. For example, in D. melanogaster, the microbiome is reported as flexible and largely environmentally determined. Therefore, microbiome-mediated RI would be transient and would break down under dietary variation. In the absence of evolutionary coassociation or recurrent exposure between host and microbiome, there are no advantages for the gut bacteria or host in effecting RI. To explore these puzzling effects and their mechanisms further, we repeated the tests for RI associated with diet-specific gut microbiomes in D. melanogaster. Despite observing replicable differences in the gut microbiomes of flies maintained on different diets, we found no evidence for diet-associated RI, for any role of gut bacteria, or for L. plantarum specifically. The results suggest that there is no general role for gut bacteria in driving the evolution of RI in this species and resolve an evolutionary riddle.

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Greenwood, Jeremy, Nezih Guner, Georgi Kocharkov, and Cezar Santos. "Technology and the Changing Family: A Unified Model of Marriage, Divorce, Educational Attainment, and Married Female Labor-Force Participation." American Economic Journal: Macroeconomics 8, no. 1 (January 1, 2016): 1–41. http://dx.doi.org/10.1257/mac.20130156.

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Marriage has declined since 1960, with the drop being more significant for noncollege-educated individuals versus college-educated ones. Divorce has increased, more so for the noncollege-educated. Additionally, positive assortative mating has risen. Income inequality among households has also widened. A unified model of marriage, divorce, educational attainment, and married female labor-force participation is developed and estimated to fit the postwar US data. Two underlying driving forces are considered: technological progress in the household sector and shifts in the wage structure. The analysis emphasizes the joint role that educational attainment, married female labor-force participation, and marital structure play in determining income inequality. (JEL D13, D31, D83, I20, J12, J16, O33)

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Croshaw, D. A., and J. H. K. Pechmann. "Size does not matter for male Marbled Salamanders (Ambystoma opacum)." Canadian Journal of Zoology 93, no. 10 (October 2015): 735–40. http://dx.doi.org/10.1139/cjz-2014-0229.

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Understanding the phenotypic attributes that contribute to variance in mating and reproductive success is crucial in the study of evolution by sexual selection. In many animals, body size is an important trait because larger individuals enjoy greater fitness due to the ability to secure more mates and produce more offspring. Among males, this outcome is largely mediated by greater success in competition with rival males and (or) advantages in attractiveness to females. Here we tested the hypothesis that large male Marbled Salamanders (Ambystoma opacum (Gravenhorst, 1807)) mate with more females and produce more offspring than small males. In experimental breeding groups, we included males chosen specifically to represent a range of sizes. After gravid females mated and nested freely, we collected egg clutches and genotyped all adults and samples of hatchlings with highly variable microsatellite markers to assign paternity. Size had little effect on male mating and reproductive success. Breeding males were not bigger than nonbreeding males, mates of polyandrous females were not smaller than those of monogamous females, and there was no evidence for positive assortative mating by size. Although body size did not matter for male Marbled Salamanders, we documented considerable fitness variation and discuss alternative traits that could be undergoing sexual selection.

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Cooper, William E., and Laurie J. Vitt. "Maximizing male reproductive success in the broad-headed skink (Eumeces laticeps): preliminary evidence for mate guarding, size-assortative pairing, and opportunistic extra-pair mating." Amphibia-Reptilia 18, no. 1 (1997): 59–73. http://dx.doi.org/10.1163/156853897x00314.

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AbstractSeveral lines of evidence suggest that male Eumeces laticeps may increase reproductive success by 1) mating with larger females to increase clutch size, 2) mate guarding to be present during the female's receptive period and/or prevent sperm competition, and 3) engaging in extra-pair copulations. Clutch size increases with female body size, establishing a potential advantage of male preference for large female mates. Mate association lasts up to 8 days and possibly longer, with a mean of nearly 5 days. Males may remain with females during a major portion of the mating season, which preliminary data suggest lasts about two weeks, suggesting that mate-guarding may reduce the level of polygyny. Tethered introductions of intruder males to consort pairs showed that consort males use aggressive behavior to exclude other males from the vicinity of females. Eumeces laticeps exhibits strong positive size-assortative pairing, suggesting the possible importance of male choice of large mates. Female preference for large males could account for this relationship, but only if large females prefer the largest possible males within the acceptable size range and aggressively exclude other females from preferred males. Females are sometimes aggressive to each other, especially near nest sites, but aggression is suppressed by males, as shown by tethered introduction of females to consort pairs. Size-assortative pairing may be based in part on male preference if males can prevent larger females from aggressively excluding smaller ones. In addition to preferentially guarding large females, males not currently guarding mate with any females not large enough to deter them aggressively. A field observation of an extra-pair copulation, responses by consort males to introduced females, and the lack of size preference in the absence of consorts suggest that males may engage opportunistically in extra-pair copulations to increase reproductive success and are not then choosy about female size.

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Slavov, Gancho T., Glenn T. Howe, and W. Thomas Adams. "Pollen contamination and mating patterns in a Douglas-fir seed orchard as measured by simple sequence repeat markers." Canadian Journal of Forest Research 35, no. 7 (July 1, 2005): 1592–603. http://dx.doi.org/10.1139/x05-082.

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Pollen contamination is detrimental to the genetic quality of seed orchard crops. Highly variable simple sequence repeat (SSR) markers make it possible to accurately measure pollen contamination and characterize patterns of within-orchard mating by directly identifying the male and female parent of each seed produced in the orchard. We used nine SSR markers to measure pollen contamination and characterize mating patterns based on seed samples collected in 3 years (1999, 2000, and 2003) from one block of a nonisolated, open-pollinated, clonal seed orchard of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in western Oregon. Pollen contamination was consistently high across the 3 years (mean = 35.3%, range = 31.0%-41.3%) and appeared to result primarily from cross-pollination among the orchard blocks. Levels of pollen contamination varied substantially among clones and were higher in clones with early female receptivity (mean = 55.5%) than in those with either mid (mean = 36.4%) or late (mean = 28.3%) female receptivity. We detected low rates of self-pollination (mean = 1.8% per clone) and over 10-fold differences in the relative paternal contributions of the clones. There was a clear pattern of positive assortative mating with respect to floral phenology. This study illustrates that SSR markers are powerful tools for characterizing seed lots and improving the design and management of Douglas-fir seed orchards.

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ANDERSON, T. J. C., R. E. L. PAUL, C. A. DONNELLY, and K. P. DAY. "Do malaria parasites mate non-randomly in the mosquito midgut?" Genetical Research 75, no. 3 (June 2000): 285–96. http://dx.doi.org/10.1017/s0016672300004481.

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Polymerase chain reaction (PCR)-based genotyping of oocysts dissected from mosquito midguts has previously been used to investigate overall levels of inbreeding within malaria parasite populations. We present a re-analysis of the population structure of Plasmodium falciparum malaria using diploid genotypes at three antigen-encoding loci in 118 oocysts dissected from 34 mosquitoes. We use these data to ask whether mating is occurring at random within the mosquito midgut, as is generally assumed. We observe a highly significant deficit of heterozygous oocysts within mosquitoes at all three loci, suggesting that fusion of gametes occurs non-randomly in the mosquito gut. A variety of biological explanations, such as interrupted feeding of mosquitoes, positive assortative mating and outcrossing depression, could account for this observation. However, an alternative artefactual explanation – the presence of non-amplifying or null alleles – can account for the observed data equally well, without the need to invoke non-random mating. To evaluate this explanation further, we estimate the frequencies of null alleles within the oocyst population using maximum likelihood, by making the assumption that non-amplifying oocysts at any of the three loci are homozygous for null alleles. Observed levels of visible heterozygotes fit closely with those expected under random mating when non-amplifying oocysts are accounted for. Other lines of evidence also support the artefactual explanation. Overall inbreeding coefficients have been recalculated in the light of this analysis, and may be considerably lower than those estimated previously. In conclusion, we suggest that the deficit of heterozygotes observed is unlikely to indicate non-random mating within the mosquito gut and is better explained by misscoring of heterozygotes as homozygotes.

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Journal articles on the topic 'Positive assortative mating'

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