The Evolution of Hermaphroditism by an Infectious Male-Derived Cell Lineage: An Inclusive-Fitness Analysis

  title={The Evolution of Hermaphroditism by an Infectious Male-Derived Cell Lineage: An Inclusive-Fitness Analysis},
  author={Andy Gardner and Laura Ross},
  journal={The American Naturalist},
  pages={191 - 201}
There has been much recent interest in the role for genetic conflicts to drive the evolution of genetic systems. Here we consider the evolution of hermaphroditism in the scale insect tribe Iceryini and the suggestion that this has been driven by conflict between a female and an infectious male tissue derived from her father. We perform an inclusive-fitness analysis to show that, owing to genetic relatedness between father and daughter, there is scope for collaboration as well as conflict over… 

Diversity of Modes of Reproduction and Sex Determination Systems in Invertebrates, and the Putative Contribution of Genetic Conflict

The different modes of reproduction among invertebrate species, highlighting sexual reproduction as the probable ancestral state; the paradoxical diversity of sex determination systems; and the different types of genetic conflicts that could drive the evolution of such different systems are reviewed.

Sexual antagonism in haplodiploids

A series of evolutionary-genetic models of sexual antagonism for haplodiploids are developed, incorporating details of their molecular biology and social ecology, and it is found that PGE promotes female-beneficial alleles more than arrhenotoky.

Paternal genome elimination promotes altruism in viscous populations

A kin‐selection model is developed to investigate how population viscosity affects the potential for altruism in species with male paternal genome elimination (PGE), finding that PGE promotes altruistic behaviors relative to the other inheritance systems, and to a degree that depends on the extent of paternal genome expression.

A general ploidy model for the evolution of helping in viscous populations.

Sexual selection modulates genetic conflicts and patterns of genomic imprinting

A kin‐selection model is developed to investigate the interests of different genes involved in sexual and intragenomic conflict, and it is shown that consideration of these conflicting interests yields novel predictions concerning parent‐of‐origin specific patterns of gene expression and the detrimental effects of different classes of mutation and epimutation at loci underpinning sexually selected phenotypes.

The Evolution of Sexual Systems in Animals

It is made that it is useful to view transitions from simultaneous hermaphroditism to dioecy as the result of selection for decreasing phenotypic plasticity and vice versa.


  • S. Weeks
  • Biology
    Evolution; international journal of organic evolution
  • 2012
In animals, such transitions were associated with size specialization between the sexes, whereas in plants these transitions were to avoid inbreeding depression, and species transitioning from hermaphroditic ancestors were more common than gynodioecious, contrasting with similar transitions in plants.

Sex Determination, Sex Chromosomes, and Karyotype Evolution in Insects

A large database on karyotypes and sex chromosomes in insects, containing information on over 13000 species covering 29 orders of insects, is established, which constitutes a unique starting point to report phylogenetic patterns on the distribution of sex determination mechanisms, sex chromosomes, and karyotype among insects.

The varied ways of being male and female

  • L. Schärer
  • Biology
    Molecular reproduction and development
  • 2017
A fascinating collection of six articles in this special issue on Hermaphroditism & Sex Determination impressively documents some important challenges to the understanding of sex determination, and the specification of male and female reproductive function when these need to occur within the same individual rather than in two separate individuals.

Endless forms most stupid, icky, and small: The preponderance of noncharismatic invertebrates as integral to a biologically sound view of life

It is shown that simple, small, and intriguingly repulsive invertebrate animals provide a counterpoint to misconceptions about evolution, and uproots evolution misconceptions, and provides a mental scaffold for understanding all animals.




  • B. Normark
  • Biology
    Evolution; international journal of organic evolution
  • 2004
This hypothesis helps to explain the ecological correlates of the origins of haplodiploidsy, as well as such otherwise puzzling phenomena as obligate cannibalism by male Micromalthus beetles, reversion to diploidy by aposymbiotic male stictococcid scale insects, and the bizarre genomic constitution of scale insect bacteriomes.

Intragenomic conflict as an evolutionary force

  • L. Hurst
  • Biology
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1992
It is argued that intragenomic conflict might be an important evolutionary force, and may influence the evolution of sex determining systems, sex allocation systems and post-zygotic isolating mechanisms.

The evolution of unusual chromosomal systems in coccoids: extraordinary sex ratios revisited

A model of the evolution of paternal genome loss in coccoids from an ancestral system of XX‐XO sex determination is presented, based on Hamilton's (1967) theory that different genetic elements within the genome have different unbeatable sex ratios.

Moving to mate: the evolution of separate and combined sexes in multicellular organisms

It is found that changes in adult mate‐search efficiency are significantly correlated with changes in breeding system, and this result is robust to uncertainties in the phylogenies.

Selfish genetic elements and their role in evolution: the evolution of sex and some of what that entails.

  • L. Hurst
  • Biology
    Philosophical transactions of the Royal Society of London. Series B, Biological sciences
  • 1995
This work has shown that sexes are the result of selection on nuclear genes to coordinate the inheritance of cytoplasmic genomes so as to prevent competition between unrelated cy toplasmics genomes and this hypothesis is tested against five comparative predictions and shown to receive considerable empirical support.

Genomic conflict in scale insects: the causes and consequences of bizarre genetic systems

The role of inter‐ and intra‐genomic conflicts in one large insect taxon: the scale insects is considered and possible experimental and comparative approaches are outlined to test more effectively how important genomic conflicts have been.

Turnover of sex chromosomes induced by sexual conflict

In this theoretical study, it is shown that an autosomal gene under sexually antagonistic selection can cause the spread of a new sex-determining gene linked to it, which can account for the origin of newSex-Determining loci, the transposition of an ancestral sex-D determining gene to an autosome, and the maintenance of multiple sex- determining factors in species that lack heteromorphic sex chromosomes.

Cytoplasmic male sterility in plants: molecular evidence and the nucleocytoplasmic conflict.

An advantage for the evolution of male haploidy and systems with similar genetic transmission

There is therefore counter-selection on fathers to produce diploid sons, and if the right genetic variation arises this countering selection will revert male haploidy to diploids, which applies to large, random-mating populations but not necessarily to inbred populations.

Sexual conflict, sex allocation and the genetic system

This work considers how biased gene transmission, as expressed in different genetic systems, enhances the opportunity for sex ratio conflict and gives empirical examples that confirm that males and females have the opportunity to influence sex ratios.