scholarly journals On the evolution of sexual receptivity in female primates

2019 ◽  
Author(s):  
Kelly Rooker ◽  
Sergey Gavrilets
Keyword(s):  
Mathematical Modeling ◽  
Group Size ◽  
Theoretical Framework ◽  
Primate Species ◽  
Sexual Receptivity ◽  
Estrus Cycle ◽  
Evolutionary Forces ◽  
Trade Offs ◽  
Reproductive Cycles ◽  
Concealed Ovulation

AbstractThere has been much interest in the evolutionary forces responsible for, and underlying the diversity in, female primate reproductive cycles. Some primate species are like humans, sexually receptive to mating throughout their entire estrus cycle, while other species are the opposite, receptive for mere hours out of their several-week cycles. Why is there such prominent variation in sexual receptivity length among primate species? Here we examine the evolutionary trade-offs associated with sexual receptivity length using mathematical modeling. We investigate how various factors, including having ovulation signs present vs. concealed ovulation, female physiological costs, and group size, each influence the length of females’ receptive periods. We find that both continuous receptivity and very short lengths of receptivity are able to evolve. Our model predicts that increasing the impacts of infanticide will increase the length of the female receptive period, emphasizing the possible importance of paternity confusion. Similar effects can also be achieved by increasing the non-genetic benefits provided by males. Overall, our work offers a theoretical framework for understanding the evolution and diversity of mating traits in female primates.

Trade-Off Analysis for the Design of a High Performance Hydrostatic Actuation System

2000 ◽  
Author(s):  
S. R. Habibi
Keyword(s):  
Mathematical Modeling ◽  
Quadratic Programming ◽  
High Performance ◽  
Design Parameters ◽  
Mathematical Functions ◽  
Trade Off ◽  
Actuation System ◽  
Trade Offs ◽  
Expected Performance ◽  
Dominant Design

Abstract This paper considers the design of a high performance hydrostatic actuation system referred to as the ElectroHydraulic Actuator (EHA). The expected performance of EHA and its dominant design parameters are identified by using mathematical modeling. The design parameters are classified into Direct and Indirect categories based on the measure of their accessibility to the designer. The Direct parameters are directly quantifiable and, can be linked to the performance of EHA through a set of mathematical functions. A prototype of EHA has been produced and described. The mathematical functions linking performance to design parameters are used to investigate design trade-offs. Design improvements to the prototype are suggested by using constrained quadratic programming.

scholarly journals Ecological aspects of black-pincelled marmoset (Callithrix penicillata) in the cerradão and dense cerrado of the Brazilian Central Plateau

2001 ◽  
Vol 61 (3) ◽  
pp. 397-404 ◽  
Author(s):  
G. H. B. de MIRANDA ◽  
D. S. de FARIA
Keyword(s):  
Home Range ◽  
Group Size ◽  
Rainy Season ◽  
Botanical Garden ◽  
Primate Species ◽  
Ecological Data ◽  
Central Plateau ◽  
Bird Eggs ◽  
Different Seasons ◽  
Gallery Forests

Ecological data about three free-ranging groups of C. penicillata (black-pincelled marmoset) were observed between March and December 1996, in one cerradão patch (in the Ecological Reserve of Brazilian Institute of Geography and Statistics, RECOR) and two patches of dense cerrado (one in the Recor and another in the Botanical Garden of Brasília, JBB), situated in the APA (area of environmental protection) of the Gama/Cabeça-de-Veado, Distrito Federal. Each area was visited weekly during three periods of two months -- end of the rainy season (01/04 to 31/05), dry season (16/06 to 15/08) and beginning of the rainy season (14/10 to 15/12) -- and instantaneous scan records at fifteen minute intervals were made for the vertical and horizontal position of each visible individual of the target group. The group size ranged between 4 and 11 elements. In September, the birth of twins in both groups of the Recor was observed. Home-range varied from 8.25 to 18.5 hectares, while density ranged from 0.4 to 0.82 ind/ha. Twenty two species of nine tree families were identified as exudate sources. Qualea grandiflora (Vochysiaceae), Vochysia thyrsoidea (Vochysiaceae), Scheflera macrocarpum (Araliaceae) and Qualea parviflora (Vochysiaceae) were more explored. Fruits (14 species, two of which were exotics), nectar, honey, arthropods (mainly orthopterans) and bird eggs complete their diet. The main sleep-tree species was Emmotum nitens (Icacinaceae). Data from different seasons and studied groups/areas were compared along previous data from this primate species in gallery forests. In the cerradão and dense cerrado areas C. penicillata had a similar group size, however a larger home-range and smaller density than in gallery forests were observed in this study.

scholarly journals Several Methods of Estrus Detection in Cattle Dams: A Review

2018 ◽  
Vol 66 (2) ◽  
pp. 619-625 ◽  
Author(s):  
Mária Mičiaková ◽  
Peter Strapák ◽  
Iveta Szencziová ◽  
Eva Strapáková ◽  
Ondrej Hanušovský
Keyword(s):  
Cycle Length ◽  
Visual Observation ◽  
Time Measurement ◽  
Sexual Receptivity ◽  
Estrus Cycle ◽  
Estrus Detection ◽  
Locomotion Activity

The oestrus is defined as a complex of physiological signs and changes of behavior occurring immediately before the ovulation. It is the period of sexual receptivity of the cow and this period characterized by, typical cow behaviour which is standing when mounted by a bull or companion cow. Cow indicates this willingness by a slight arching of the back and immobility when approached. The bovine estrus cycle averages 20 days in heifers and 21 days in cows, but the fluctuations in the cycle length is laying between 18 and 25 days. As a result of this progress often only 50 % of the estrus cycles are recognized, and it is extremely hard to find all cows on heat. We state a few methods for estrus detection such as visual observation, locomotion activity and rumination time measurement and other.

scholarly journals Effect of Group Size and Individual Characteristics on Intergroup Encounters in Primates

2020 ◽  
Vol 41 (2) ◽  
pp. 325-341 ◽  
Author(s):  
Bonaventura Majolo ◽  
Aurora deBortoli Vizioli ◽  
Laura Martínez-Íñigo ◽  
Julia Lehmann
Keyword(s):  
Group Size ◽  
Dominance Rank ◽  
Individual Characteristics ◽  
Primate Species ◽  
New World Monkeys ◽  
Older Individuals ◽  
Data Set ◽  
Unequal Distribution ◽  
Intergroup Encounters ◽  
Group 2

AbstractIntergroup encounters are common in nonhuman primates and can vary from affiliative to aggressive. We extracted data from the literature to test five different hypotheses: 1) where there are group size differences between opposing groups, whether the larger group is more likely to win an intergroup encounter than the smaller group; 2) whether the likelihood of a group engaging in aggressive intergroup encounters increases with group size; and 3–5) whether dominant, older individuals, and/or males are more likely to participate aggressively in intergroup encounters than subordinate, younger individuals and/or females. Our data set comprised 52 studies on 31 primate species (3 lemur species, 5 New World monkeys, 19 Old World monkeys, and 4 apes). We found that the larger group is more likely to win an encounter against a smaller group than vice versa. We found no significant relationship between group size and propensity to be aggressive during intergroup encounters. We found weak/no support for the effect of age, dominance rank, and sex on the frequency of aggression displayed toward outgroup individuals during intergroup encounters. Species- and population-specific differences in inter- and intragroup competition and in the degree of the unequal distribution of resources across group members may explain why age, dominance rank, and sex are not strong predictors of aggression during intergroup encounters.

scholarly journals The multinomial index: a robust measure of reproductive skew

2020 ◽  
Vol 287 (1936) ◽  
pp. 20202025
Author(s):  
Cody T. Ross ◽  
Adrian V. Jaeggi ◽  
Monique Borgerhoff Mulder ◽  
Jennifer E. Smith ◽  
Eric Alden Smith ◽  
...  
Keyword(s):  
Group Size ◽  
Social Evolution ◽  
Natural Populations ◽  
R Package ◽  
Reproductive Skew ◽  
Primate Species ◽  
Highly Sensitive ◽  
Highly Nonlinear ◽  
Population Comparisons ◽  
Negative Effect

Inequality or skew in reproductive success (RS) is common across many animal species and is of long-standing interest to the study of social evolution. However, the measurement of inequality in RS in natural populations has been challenging because existing quantitative measures are highly sensitive to variation in group/sample size, mean RS, and age-structure. This makes comparisons across multiple groups and/or species vulnerable to statistical artefacts and hinders empirical and theoretical progress. Here, we present a new measure of reproductive skew, the multinomial index, M , that is unaffected by many of the structural biases affecting existing indices. M is analytically related to Nonacs’ binomial index, B , and comparably accounts for heterogeneity in age across individuals; in addition, M allows for the possibility of diminishing or even highly nonlinear RS returns to age. Unlike B , however, M is not biased by differences in sample/group size. To demonstrate the value of our index for cross-population comparisons, we conduct a reanalysis of male reproductive skew in 31 primate species. We show that a previously reported negative effect of group size on mating skew was an artefact of structural biases in existing skew measures, which inevitably decline with group size; this bias disappears when using M . Applying phylogenetically controlled, mixed-effects models to the same dataset, we identify key similarities and differences in the inferred within- and between-species predictors of reproductive skew across metrics. Finally, we provide an R package, SkewCalc , to estimate M from empirical data.

scholarly journals Group augmentation, collective action, and territorial boundary patrols by male chimpanzees

2017 ◽  
Vol 114 (28) ◽  
pp. 7337-7342 ◽  
Author(s):  
Kevin E. Langergraber ◽  
David P. Watts ◽  
Linda Vigilant ◽  
John C. Mitani
Keyword(s):  
Collective Action ◽  
Group Size ◽  
Dominance Rank ◽  
Primate Species ◽  
Collective Good ◽  
Collective Action Problems ◽  
High Dominance ◽  
Participation Costs ◽  
Low Costs

How can collective action evolve when individuals benefit from cooperation regardless of whether they pay its participation costs? According to one influential perspective, collective action problems are common, especially when groups are large, but may be solved when individuals who have more to gain from the collective good or can produce it at low costs provide it to others as a byproduct. Several results from a 20-y study of one of the most striking examples of collective action in nonhuman animals, territorial boundary patrolling by male chimpanzees, are consistent with these ideas. Individuals were more likely to patrol when (i) they had more to gain because they had many offspring in the group; (ii) they incurred relatively low costs because of their high dominance rank and superior physical condition; and (iii) the group size was relatively small. However, several other findings were better explained by group augmentation theory, which proposes that individuals should bear the short-term costs of collective action even when they have little to gain immediately if such action leads to increases in group size and long-term increases in reproductive success. In support of this theory, (i) individual patrolling effort was higher and less variable than participation in intergroup aggression in other primate species; (ii) males often patrolled when they had no offspring or maternal relatives in the group; and (iii) the aggregate patrolling effort of the group did not decrease with group size. We propose that group augmentation theory deserves more consideration in research on collective action.

scholarly journals The masquerade game: marine mimicry adaptation between egg-cowries and octocorals

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2051 ◽  
Author(s):  
Juan A. Sánchez ◽  
Angela P. Fuentes-Pardo ◽  
Íde Ní Almhain ◽  
Néstor E. Ardila-Espitia ◽  
Jaime Cantera-Kintz ◽  
...  
Keyword(s):  
Evolutionary Relationship ◽  
General Assumption ◽  
Mitochondrial Genes ◽  
Snail Species ◽  
Tropical Eastern Pacific ◽  
Marine Gastropods ◽  
Evolutionary Forces ◽  
Background Matching ◽  
Trade Offs ◽  
Malpelo Island

Background.Background matching, as a camouflage strategy, is one of the most outstanding examples of adaptation, where little error or mismatch means high vulnerability to predation. It is assumed that the interplay of natural selection and adaptation are the main evolutionary forces shaping the great diversity of phenotypes observed in mimicry; however, there may be other significant processes that intervene in the development of mimicry such as phenotypic plasticity. Based on observations of background mismatching during reproduction events of egg-cowries, sea snails of the family Ovulidae that mimic the octocoral where they inhabit, we wondered if they match the host species diversity. Using observations in the field and molecular systematics, we set out to establish whether the different egg-cowrie color/shape polymorphisms correspond to distinct lineages restricted to specific octocoral species.Methods.Collection and observations of egg-cowries and their octocoral hosts were done using SCUBA diving between 2009 and 2012 at two localities in the Tropical Eastern Pacific (TEP), Malpelo Island and Cabo Corrientes (Colombia). Detailed host preference observations were done bi-annually at Malpelo Island. We analyzed the DNA sequence of the mitochondrial genesCOIand16S rDNA, extensively used in phylogenetic and DNA barcoding studies, to assess the evolutionary relationship among different egg-cowrie colorations and morphologies.Results.No genetic divergence among egg-cowries associated to different species of the same octocoral genus was observed based on the two mitochondrial genes analyzed. For instance, all egg-cowrie individuals from the two sampled localities observed on 8 differentPacifigorgia-Eugorgiaspecies showed negligible mitochondrial divergence yet large morphologic divergence, which suggests that morphologies belonging to at least two sea snail species,Simnia avena(=S. aequalis) andSimnialena rufa, can cross-fertilize.Discussion.Our study system comprised background-matching mimicry, of the masquerade type, between egg-cowries (Simnia/Simnialena) and octocorals (Pacifigorgia/Eugorgia/Leptogorgia). We observed mimicry mismatches related to fitness trade-offs, such as reproductive aggregations vs. vulnerability against predators. Despite the general assumption that coevolution of mimicry involves speciation, egg-cowries with different hosts and colorations comprise the same lineages. Consequently, we infer that there would be significant tradeoffs between mimicry and the pursuit of reproductive aggregations in egg-cowries. The findings of this study not only contribute to the understanding of the evolution of mimicry in egg-cowries, a poorly studied group of marine gastropods, but also to the development of a new biologically meaningful board game that could be implemented as a learning tool.

Exploring the Culture of Surveillance: A Qualitative Study in Portugal

2021 ◽  
Vol 10 (1) ◽  
pp. 79-95
Author(s):  
Délcio Faustino ◽  
Maria João Simões
Keyword(s):  
Qualitative Study ◽  
Detailed Analysis ◽  
Social Inequalities ◽  
Cost Benefit ◽  
Theoretical Framework ◽  
Surveillance Culture ◽  
Trade Off ◽  
Trade Offs ◽  
The Cost ◽  
Subjective Meanings

By following the theoretical framework of the surveillance culture this article aims to detail the surveillance imaginaries and practices that individuals have, capturing differences and social inequalities among respondents. We present an in-depth look into surveillance awareness, exploring subjective meanings and the varying awareness regarding commercial, governmental, and lateral surveillance. Furthermore, a detailed analysis is made on how individuals sometimes welcome surveillance, expanding on the cost-benefit trade-off, and detailing it on three distinct trade-offs: the privacy vs. commercial gains/rewards, the privacy vs. convenience and, the privacy vs. security. Lastly, we present a section that explores and analyzes resistance to surveillance.

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