scholarly journals Same-sex sexual behavior and selection for indiscriminate mating

2020 ◽  
Author(s):  
Brian A Lerch ◽  
Maria R Servedio
Keyword(s):  
Sexual Behavior ◽  
Sexual Reproduction ◽  
Optimal Strategy ◽  
Strong Support ◽  
Same Sex ◽  
Evolutionary Origins ◽  
Wide Range ◽  
Selection For ◽  
The Cost ◽  
Time And Energy

The widespread presence of same-sex sexual behavior (SSB) has long been thought to pose an evolutionary conundrum1-3, as participants in SSB suffer the cost of failing to reproduce after expending the time and energy to find a mate. The potential for SSB to occur as part of an optimal strategy has received almost no attention, although indiscriminate sexual behavior may be the ancestral mode of sexual reproduction4. Here, we build a simple model of sexual reproduction and create a theoretical framework for the evolution of indiscriminate sexual behavior. We provide strong support for the hypothesis that SSB is likely maintained by selection for indiscriminate sexual behavior, by showing that indiscriminate mating is the optimal strategy under a wide range of conditions. Further, our model suggests that the conditions that most strongly favor indiscriminate mating were likely present at the origin of sexual behavior. These findings have implications not only for the evolutionary origins of SSB, but also for the evolution of discriminate sexual behavior across the animal kingdom.

One Final Word: Sex

2003 ◽  
Author(s):  
Mary Jane West-Eberhard
Keyword(s):  
Sexual Reproduction ◽  
Kin Selection ◽  
Genetic Similarity ◽  
Best Interests ◽  
Evolution Of Sex ◽  
Sexual Generation ◽  
History Of ◽  
The Cost ◽  
And Behavior ◽  
Time And Energy

Sex transforms life. It affects morphology and behavior. It diverts enormous amounts of time and energy from the business of survival. It can even distract from the manufacture and safe packaging of offspring. The adolescent metamorphosis we each experience once, and thereafter view with amazement, in the relative calm of adulthood, has swept through nature on a grand scale, culminating in orchid flowers and peacock tails. All of this is due to chromosomal recombination—sex sensu strictu (Ghiselin, 1974)—and its organismal result, sexual reproduction or cooperation between two individuals to produce offspring. It is sex as sexual reproduction, the developmental side of sex that initiates the ontogeny of new individuals, that I mainly discuss here, though it is sex as recombination— the genetic side of sex—that has received most attention in discussions of the maintenance of sex. Of all the major transformations in the history of life, the evolution of sex is the most enigmatic. The question is not so much how sex got there as why it remains. Given the importance of genetic similarity, or kin selection (Hamilton, 1964a,b), for the maintenance of cooperation within and among organisms, sex seems designed to be disruptive. It requires the union of genetically dissimilar individuals, which dilutes the relatedness of mother and young, leaving the mother to invest in offspring genetically only half like herself. This has been called “the cost of meiosis” or the “twofold cost of sex” (Williams, 1975). It is a cost that usually falls to females, with their greater investment in eggs and care of offspring. By this view, the male is a parasite of his mate and participation in sexual reproduction is contrary to the best interests of females, who would do better to reproduce parthenogenetically on their own. Yet, among animals, only about one in one thousand species are thelytokous, that is, secondarily asexual, with no facultative or alternating sexual generation and no interaction with males. The prevalence of sexual reproduction in higher organisms is “inconsistent with current evolutionary theory” (Williams, 1975, p. v).

scholarly journals The evolutionary origins of modularity

2013 ◽  
Vol 280 (1755) ◽  
pp. 20122863 ◽  
Author(s):  
Jeff Clune ◽  
Jean-Baptiste Mouret ◽  
Hod Lipson
Keyword(s):  
Biological Networks ◽  
Network Performance ◽  
Indirect Selection ◽  
Direct Selection ◽  
Network Nodes ◽  
Evolutionary Origins ◽  
Modular Networks ◽  
Key Driver ◽  
Selection For ◽  
The Cost

A central biological question is how natural organisms are so evolvable (capable of quickly adapting to new environments). A key driver of evolvability is the widespread modularity of biological networks—their organization as functional, sparsely connected subunits—but there is no consensus regarding why modularity itself evolved. Although most hypotheses assume indirect selection for evolvability, here we demonstrate that the ubiquitous, direct selection pressure to reduce the cost of connections between network nodes causes the emergence of modular networks. Computational evolution experiments with selection pressures to maximize network performance and minimize connection costs yield networks that are significantly more modular and more evolvable than control experiments that only select for performance. These results will catalyse research in numerous disciplines, such as neuroscience and genetics, and enhance our ability to harness evolution for engineering purposes.

scholarly journals Sexual selection for rare beneficial mutations promotes the evolution of sexual reproduction and adaptation

2021 ◽  
Author(s):  
Gilbert Roberts ◽  
Marion Petrie
Keyword(s):  
Sexual Selection ◽  
Sexual Reproduction ◽  
Negative Impact ◽  
Reproductive Rate ◽  
Beneficial Mutations ◽  
Selection For ◽  
The Cost ◽  
Average Fitness ◽  
Cost Of Sex

The evolution and widespread maintenance of sexual reproduction remains a conundrum in biology because asexual reproduction should allow twice the reproductive rate. One hypothesis is that sexual selection lessens the negative impact on fitness of accumulating deleterious mutations. However, for adaptation to occur, there must also be selection for beneficial mutations. Here we show that sexual selection can help explain the evolution and maintenance of sexual reproduction. In our model, females chose males with more beneficial mutations (as opposed to just fewer harmful ones) even when these occurred much more rarely. Sexual selection thereby increased fixation of beneficial mutations which increased the absolute genetic quality of sexual offspring. This increase in fitness relative to asexual offspring adds to the previously postulated effect of reduced mutation load in offsetting the cost of sex. Analysing our simulations reveals that female choice among males raised the fitness of reproducing males above that of females. We found that this effect could overcome the decline in average fitness that occurs when mutation rate increases, allowing an increase in the fixation of beneficial mutations. Sexual selection thereby not only facilitates the evolution of sexual reproduction but maintains sex by leveraging its benefits and driving adaptation.

IMPROVEMENT OF INNOVATIVE ACTIVITY OF THE ENTERPRISE

2017 ◽  
Author(s):  
Nataliya Stoyanets ◽  
◽  
Mathias Onuh Aboyi ◽  
Keyword(s):  
Value Chain ◽  
Net Present Value ◽  
Successful Implementation ◽  
Innovative Development ◽  
Technological Equipment ◽  
Alliance Partner ◽  
Innovation Potential ◽  
Wide Range ◽  
Technological Platform ◽  
The Cost

The article defines that for the successful implementation of an innovative project and the introduction of a new product into production it is necessary to use advanced technologies and modern software, which is an integral part of successful innovation by taking into account the life cycle of innovations. It is proposed to consider the general potential of the enterprise through its main components, namely: production and technological, scientific and technical, financial and economic, personnel and actual innovation potential. Base for the introduction of technological innovations LLC "ALLIANCE- PARTNER", which provides a wide range of support and consulting services, services in the employment market, tourism, insurance, translation and more. To form a model of innovative development of the enterprise, it is advisable to establish the following key aspects: the system of value creation through the model of cooperation with partners and suppliers; creating a value chain; technological platform; infrastructure, determine the cost of supply, the cost of activities for customers and for the enterprise as a whole. The system of factors of influence on formation of model of strategic innovative development of the enterprise is offered. The expediency of the cost of the complex of technological equipment, which is 6800.0 thousand UAH, is economically calculated. Given the fact that the company plans to receive funds under the program of socio-economic development of Sumy region, the evaluation of the effectiveness of the innovation project, the purchase of technological equipment, it is determined that the payback period of the project is 3 years 10 months. In terms of net present value (NPV), the project under study is profitable. The project profitability index (PI) meets the requirements for a positive decision on project implementation> 1.0. The internal rate of return of the project (IRR) also has a positive value of 22% because it exceeds the discount rate.

scholarly journals Microsatellite and Chromosome Evolution of Parthenogenetic Sitobion Aphids in Australia

Genetics ◽  
1996 ◽  
Vol 144 (2) ◽  
pp. 747-756 ◽  
Author(s):  
Paul Sunnucks ◽  
Phillip R England ◽  
Andrea C Taylor ◽  
Dinah F Hales
Keyword(s):  
Sexual Reproduction ◽  
Chromosome Evolution ◽  
Genetic Recombination ◽  
Allelic Variation ◽  
Repeat Unit ◽  
Chromosomal Evolution ◽  
Microsatellite Variation ◽  
Wide Range ◽  
Sexual Recombination ◽  
Minimum Numbers

Abstract Single-locus microsatellite variation correlated perfectly with chromosome number in Sitobion miscanthi aphids. The microsatellites were highly heterozygous, with up to 10 alleles per locus in this species. Despite this considerable allelic variation, only seven different S. miscanthi genotypes were discovered in 555 individuals collected from a wide range of locations, hosts and sampling periods. Relatedness between genotypes suggests only two successful colonizations of Australia. There was no evidence for genetic recombination in 555 S. miscanthi so the occurrence of recent sexual reproduction must be near zero. Thus diversification is by mutation and chromosomal rearrangement alone. Since the aphids showed no sexual recombination, microsatellites can mutate without meiosis. Five of seven microsatellite differences were a single repeat unit, and one larger jump is likely. The minimum numbers of changes between karyotypes corresponded roughly one-to-one with microsatellite allele changes, which suggests very rapid chromosomal evolution. A chromosomal fission occurred in a cultured line, and a previously unknown chromosomal race was detected. All 121 diverse S. near fragariae were heterozygous but revealed only one genotype. This species too must have a low rate of sexual reproduction and few colonizations of Australia.

scholarly journals Ring-Forming Polymerization toward Perfluorocyclobutyl and Ortho-Diynylarene-Derived Materials: From Synthesis to Practical Applications

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1486
Author(s):  
Eugene B. Caldona ◽  
Ernesto I. Borrego ◽  
Ketki E. Shelar ◽  
Karl M. Mukeba ◽  
Dennis W. Smith
Keyword(s):  
Chemical Resistance ◽  
Structural Features ◽  
Review Article ◽  
Aryl Ether ◽  
Aromatic Rings ◽  
Practical Applications ◽  
Repeat Units ◽  
Wide Range ◽  
Synthetic Routes ◽  
The Cost

Many desirable characteristics of polymers arise from the method of polymerization and structural features of their repeat units, which typically are responsible for the polymer’s performance at the cost of processability. While linear alternatives are popular, polymers composed of cyclic repeat units across their backbones have generally been shown to exhibit higher optical transparency, lower water absorption, and higher glass transition temperatures. These specifically include polymers built with either substituted alicyclic structures or aromatic rings, or both. In this review article, we highlight two useful ring-forming polymer groups, perfluorocyclobutyl (PFCB) aryl ether polymers and ortho-diynylarene- (ODA) based thermosets, both demonstrating outstanding thermal stability, chemical resistance, mechanical integrity, and improved processability. Different synthetic routes (with emphasis on ring-forming polymerization) and properties for these polymers are discussed, followed by their relevant applications in a wide range of aspects.

scholarly journals A Threat of Farmers’ Suicide and the Opportunity in Organic Farming for Sustainable Agricultural Development in India

2019 ◽  
Vol 11 (8) ◽  
pp. 2400 ◽  
Author(s):  
Karthikeyan Mariappan ◽  
Deyi Zhou
Keyword(s):  
Organic Farming ◽  
Tamil Nadu ◽  
Agricultural Development ◽  
Small Scale ◽  
Conventional Farming ◽  
Wide Range ◽  
Significant Difference ◽  
Small Scale Farmers ◽  
The Cost ◽  
Input Cost

Agriculture is the main sources of income for humans. Likewise, agriculture is the backbone of the Indian economy. In India, Tamil Nadu regional state has a wide range of possibilities to produce all varieties of organic products due to its diverse agro-climatic condition. This research aimed to identify the economics and efficiency of organic farming, and the possibilities to reduce farmers’ suicides in the Tamil Nadu region through the organic agriculture concept. The emphasis was on farmers, producers, researchers, and marketers entering the sustainable economy through organic farming by reducing input cost and high profit in cultivation. A survey was conducted to gather data. One way analysis of variance (ANOVA) has been used to test the hypothesis regards the cost and profit of rice production. The results showed that there was a significant difference in profitability between organic and conventional farming methods. It is very transparent that organic farming is the leading concept of sustainable agricultural development with better organic manures that can improve soil fertility, better yield, less input cost and better return than conventional farming. The study suggests that by reducing the cost of cultivation and get a marginal return through organic farming method to poor and small scale farmers will reduce socio-economic problems such as farmers’ suicides in the future of Indian agriculture.

Keynote

2021 ◽  
Vol 48 (4) ◽  
pp. 3-3
Author(s):  
Ingo Weber
Keyword(s):  
Cost Estimation ◽  
Estimation Method ◽  
Main Topic ◽  
System Throughput ◽  
Distributed Ledger ◽  
Smart Contract ◽  
Distributed Ledger Technology ◽  
Wide Range ◽  
The Cost ◽  
Application Developers

Blockchain is a novel distributed ledger technology. Through its features and smart contract capabilities, a wide range of application areas opened up for blockchain-based innovation [5]. In order to analyse how concrete blockchain systems as well as blockchain applications are used, data must be extracted from these systems. Due to various complexities inherent in blockchain, the question how to interpret such data is non-trivial. Such interpretation should often be shared among parties, e.g., if they collaborate via a blockchain. To this end, we devised an approach codify the interpretation of blockchain data, to extract data from blockchains accordingly, and to output it in suitable formats [1, 2]. This work will be the main topic of the keynote. In addition, application developers and users of blockchain applications may want to estimate the cost of using or operating a blockchain application. In the keynote, I will also discuss our cost estimation method [3, 4]. This method was designed for the Ethereum blockchain platform, where cost also relates to transaction complexity, and therefore also to system throughput.

MARGINALIZED YET MOBILIZED

2019 ◽  
Vol 16 (1) ◽  
pp. 131-156 ◽  
Author(s):  
Alecia J. McGregor ◽  
Laura M. Bogart ◽  
Molly Higgins-Biddle ◽  
Dara Z. Strolovitch ◽  
Bisola Ojikutu
Keyword(s):  
Sexual Behavior ◽  
Political Participation ◽  
Original Data ◽  
Preliminary Evidence ◽  
Same Sex ◽  
Electoral Outcomes ◽  
Marginalized Groups ◽  
Nationally Representative ◽  
Lgbt People ◽  
The Relationship

AbstractBoth African American and LGBT voters can prove pivotal in electoral outcomes, but we know little about civic participation among Black LGBT people. Although decades of research on political participation has made it almost an article of faith that members of dominant groups (such as White people and individuals of higher socioeconomic status) vote at higher rates than their less privileged counterparts, recent work has suggested that there are circumstances under which members of marginalized groups might participate at higher rates. Some of this research suggests that political participation might also increase when groups perceive elections as particularly threatening. We argue that when such threats are faced by marginalized groups, the concern to protect hard-earned rights can activate a sense of what we call “political hypervigilance,” and that such effects may be particularly pronounced among members of intersectionally-marginalized groups such as LGBT African Americans. To test this theory, we use original data from the 2016 National Survey on HIV in the Black Community, a nationally-representative survey of Black Americans, to explore the relationship among same-sex sexual behavior, attitudes toward LGBT people, and respondent voting intentions in the 2016 presidential election. We find that respondents who reported having engaged in same-sex sexual behavior were strongly and significantly more likely to say they “definitely will vote” compared to respondents who reported no same-sex sexual behavior. More favorable views of LGBT individuals and issues (marriage equality) were also associated with greater intention to vote. We argue that these high rates provide preliminary evidence that political hypervigilance can, in fact, lead to increased political engagement among members of marginalized groups.

scholarly journals Same-Sex Sexual Behavior and Psychiatric Disorders

2001 ◽  
Vol 58 (1) ◽  
pp. 85 ◽  
Author(s):  
Theo G. M. Sandfort ◽  
Ron de Graaf ◽  
Rob V. Bijl ◽  
Paul Schnabel
Keyword(s):  
Sexual Behavior ◽  
Psychiatric Disorders ◽  
Same Sex
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