Migration Restores Hybrid Incompatibility Driven By Nuclear-Mitochondrial Sexual Conflict

AbstractIn the mitochondrial genome, sexual asymmetry in transmission favors mutations that are advantageous in females even if they are deleterious in males. Called the “Mother’s Curse”, this phenomenon induces a selective pressure for nuclear variants that compensate for this reduction in male fitness. Previous work has demonstrated not only the existence of these interactions but also their potential for acting as Dobzhansky–Muller loci. However, it is not clear how readily they would give rise to and sustain hybrid incompatibilities. Here, we use computer simulations in SLiM 3 to expand analytical theory to investigate the consequences of sexually antagonistic mitochondrial-nuclear interactions in a subdivided population. We consider distinct migration schemes and vary the chromosomal location, and consequently the transmission pattern, of nuclear restorers. Disrupting these co-evolved interactions results in less-fit males skewing the sex ratio towards females. Restoration of male fitness depends on both the chromosomal location of nuclear restorers and the migration scheme. Our results show that these interactions may act as Dobzhansky–Muller incompatibilities, but their strength is not enough to drive population isolation. Combined, this model shows the varied ways in which populations respond to migration’s disruption of co-evolved mitochondrial-nuclear interactions.

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Sibling quality and the haplodiploidy hypothesis

Biology Letters ◽

10.1098/rsbl.2019.0764 ◽

2020 ◽

Vol 16 (3) ◽

pp. 20190764 ◽

Cited By ~ 1

Author(s):

P. Kennedy ◽

A. N. Radford

Keyword(s):

Sex Ratio ◽

Kin Selection ◽

Selection Model ◽

Male Fitness ◽

Female Fitness ◽

Evolution Of Eusociality ◽

Insect Biology ◽

Relatedness Asymmetry

The ‘haplodiploidy hypothesis’ argues that haplodiploid inheritance in bees, wasps, and ants generates relatedness asymmetries that promote the evolution of altruism by females, who are less related to their offspring than to their sisters (‘supersister’ relatedness). However, a consensus holds that relatedness asymmetry can only drive the evolution of eusociality if workers can direct their help preferentially to sisters over brothers, either through sex-ratio biases or a pre-existing ability to discriminate sexes among the brood. We show via a kin selection model that a simple feature of insect biology can promote the origin of workers in haplodiploids without requiring either condition. In insects in which females must found and provision new nests, body quality may have a stronger influence on female fitness than on male fitness. If altruism boosts the quality of all larval siblings, sisters may, therefore, benefit more than brothers from receiving the same amount of help. Accordingly, the benefits of altruism would fall disproportionately on supersisters in haplodiploids. Haplodiploid females should be more prone to altruism than diplodiploid females or males of either ploidy when altruism elevates female fitness especially, and even when altruists are blind to sibling sex.

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War and the evolution of belligerence and bravery

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2008.0842 ◽

2008 ◽

Vol 275 (1653) ◽

pp. 2877-2885 ◽

Cited By ~ 49

Author(s):

Laurent Lehmann ◽

Marcus W Feldman

Keyword(s):

Human Evolution ◽

Population Genetic ◽

Selective Pressure ◽

Genetic Model ◽

Material Resources ◽

Population Genetic Model ◽

Large Size ◽

Subdivided Population ◽

Enhancing Resources

Tribal war occurs when a coalition of individuals use force to seize reproduction-enhancing resources, and it may have affected human evolution. Here, we develop a population-genetic model for the coevolution of costly male belligerence and bravery when war occurs between groups of individuals in a spatially subdivided population. Belligerence is assumed to increase an actor's group probability of trying to conquer another group. An actor's bravery is assumed to increase his group's ability to conquer an attacked group. We show that the selective pressure on these two traits can be substantial even in groups of large size, and that they may be driven by two independent reproduction-enhancing resources: additional mates for males and additional territory (or material resources) for females. This has consequences for our understanding of the evolution of intertribal interactions, as hunter-gatherer societies are well known to have frequently raided neighbouring groups from whom they appropriated territory, goods and women.

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Reproductive incompatibility between genetically differentiated populations of Tetranychus urticae from different host plants

ENTOMOLOGIA HELLENICA ◽

10.12681/eh.11532 ◽

2017 ◽

Vol 23 (1) ◽

pp. 29 ◽

Cited By ~ 2

Author(s):

Natasa Fytrou ◽

Anastasia Tsagkarakou

Keyword(s):

Sex Ratio ◽

Tetranychus Urticae ◽

Host Plants ◽

Reproductive Potential ◽

Female Offspring ◽

Agricultural Pests ◽

Population Isolation ◽

Citrus Grove ◽

F1 Hybrid ◽

Host Plant Adaptation

The study of host plant adaptation in arthropods, and especially agricultural pests, presents great interest, as it relates to patterns of population isolation and differentiation, with effects ranging from gene flow restriction to speciation. Prompted by our earlier isoenzyme studies that revealed genetic differentiation of Tetranychus urticae (Koch) collected on citrus, compared to other host plants, we investigated crossing compatibility between T. urticae collected from citrus (lemon) trees (ELCI) and T. urticae collected from the weed Mercurialis annua (ELMA), in the same citrus grove. Crossing compatibility in haplodiploid species where unfertilised eggs develop into males, like T. urticae, is assessed based on both the number and the sex ratio of the offspring. When ELMA females were crossed with ELCI males, fecundity was not affected, however the sex ratio was significantly biased towards males (16.6 % females, compared to 66% in the control cross ELMAxELMA). In the reciprocal crosses (ELCIxELMA), fecundity was lower by 30% and the proportion of female offspring was reduced to 52% from 67 %, compared to the control. The fecundity of the F1 hybrid females was significantly reduced and the eggs they laid were less viable, compared to the non-hybrids, further reducing the reproductive potential of inter-strain crosses. Combined with previous data, these results suggest the existence of a citrus-associated T. urticae host race.

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The role of chromosomal inversions in speciation

10.1101/211771 ◽

2017 ◽

Cited By ~ 3

Author(s):

Z.L. Fuller ◽

C.J. Leonard ◽

R.E. Young ◽

S.W. Schaeffer ◽

N Phadnis

Keyword(s):

Sex Ratio ◽

Natural Variation ◽

Ancestral Population ◽

Emergent Properties ◽

Reproductive Barriers ◽

Hybrid Incompatibility ◽

Evolutionary Forces ◽

Chromosomal Inversions ◽

Incompatibility Alleles

The chromosomal inversions of D. persimilis and D. pseudoobscura have deeply influenced our understanding of the evolutionary forces that shape natural variation, speciation, and selfish chromosome dynamics. Here, we perform a comprehensive reconstruction of the evolutionary histories of the chromosomal inversions in these species. We provide a solution to the puzzling origins of the selfish Sex-Ratio chromosome in D. persimilis and show that this Sex-Ratio chromosome directly descends from an ancestrally-arranged chromosome. Our results further show that all fixed inversions between D. persimilis and D. pseudoobscura were segregating in the ancestral population long before speciation, and that the genes contributing to reproductive barriers between these species must have evolved within them afterwards. We propose a new model for the role of chromosomal inversions in speciation and suggest that higher levels of divergence and an association with hybrid incompatibilities are emergent properties of ancestrally segregating inversions. These findings force a reconsideration of the role of chromosomal inversions in speciation, not as protectors of existing hybrid incompatibility alleles, but as fertile grounds for their formation.

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A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100055904 ◽

1982 ◽

Vol 40 ◽

pp. 722-723 ◽

Cited By ~ 1

Author(s):

R. Gronsky

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

High Resolution ◽

Computer Simulations ◽

Structural Characteristics ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

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Multislice calculations for quasi-periodic and non-periodic objects

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100173820 ◽

1990 ◽

Vol 48 (4) ◽

pp. 138-139

Author(s):

R. Herrera ◽

A. Gómez

Keyword(s):

Electron Diffraction ◽

Computer Simulations ◽

Periodic Table ◽

Amorphous Materials ◽

Space Group ◽

Essential Step ◽

Shape Effects ◽

Atomic Scattering ◽

Diffraction Patterns ◽

Periodic Continuation

Computer simulations of electron diffraction patterns and images are an essential step in the process of structure and/or defect elucidation. So far most programs are designed to deal specifically with crystals, requiring frequently the space group as imput parameter. In such programs the deviations from perfect periodicity are dealt with by means of “periodic continuation”.However, for many applications involving amorphous materials, quasiperiodic materials or simply crystals with defects (including finite shape effects) it is convenient to have an algorithm capable of handling non-periodicity. Our program “HeGo” is an implementation of the well known multislice equations in which no periodicity assumption is made whatsoever. The salient features of our implementation are: 1) We made Gaussian fits to the atomic scattering factors for electrons covering the whole periodic table and the ranges [0-2]Å−1 and [2-6]Å−1.

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Computer simulations for the TEM bend contour technique

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100163137 ◽

1996 ◽

Vol 54 ◽

pp. 134-135

Author(s):

Vladimir Yu. Kolosov ◽

Anders R. Thölén

Keyword(s):

Computer Simulations ◽

Real Space ◽

Advantages And Disadvantages ◽

Short Overview ◽

Diffraction Contrast ◽

Beam Method ◽

Convergent Beam ◽

Contour Technique

In this paper we give a short overview of two TEM applications utilizing the extinction bend contour technique (BC) giving the advantages and disadvantages; especially we consider two areas in which the BC technique remains unique. Special attention is given to an approach including computer simulations of TEM micrographs.BC patterns are often observed in TEM studies but are rarely exploited in a serious way. However, this type of diffraction contrast was one of the first to be used for analysis of imperfections in crystalline foils, but since then only some groups have utilized the BC technique. The most extensive studies were performed by Steeds, Eades and colleagues. They were the first to demonstrate the unique possibilities of the BC method and named it real space crystallography, which developed later into the somewhat similar but more powerful convergent beam method. Maybe, due to the difficulties in analysis, BCs have seldom been used in TEM, and then mainly to visualize different imperfections and transformations.

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