scholarly journals Sperm should evolve to make female meiosis fair.

2014 ◽  
Author(s):  
Yaniv Brandvain ◽  
Graham Coop
Keyword(s):  
Population Genetic ◽  
Animal Species ◽  
Meiotic Drive ◽  
Female Meiosis ◽  
Genetic Theory ◽  
Evolutionary Advantage ◽  
The Face ◽  
Perceived Danger ◽  
Organismal Fitness

Genomic conflicts arise when an allele gains an evolutionary advantage at a cost to organismal fitness. Oogenesis is inherently susceptible to such conflicts because alleles compete for inclusion into the egg. Alleles that distort meiosis in their favor (i.e. meiotic drivers) often decrease organismal fitness, and therefore indirectly favor the evolution of mechanisms to suppress meiotic drive. In this light, many facets of oogenesis and gametogenesis have been interpreted as mechanisms of protection against genomic outlaws. That females of many animal species do not complete meiosis until after fertilization, appears to run counter to this interpretation, because this delay provides an opportunity for sperm-acting alleles to meddle with the outcome of female meiosis and help like alleles drive in heterozygous females. Contrary to this perceived danger, the population genetic theory presented herein suggests that, in fact, sperm nearly always evolve to increase the fairness of female meiosis in the face of genomic conflicts. These results are consistent with the apparent sperm dependence of the best characterized female meiotic drivers in animals. Rather than providing an opportunity for sperm collaboration in female meiotic drive, the 'fertilization requirement' indirectly protects females from meiotic drivers by providing sperm an opportunity to suppress drive.

Population Genetic Theory of the Cost of Inbreeding

1984 ◽  
Vol 123 (5) ◽  
pp. 642-653 ◽  
Author(s):  
Marcus Feldman ◽  
Freddy B. Christiansen
Keyword(s):  
Population Genetic ◽  
Genetic Theory ◽  
The Cost

scholarly journals Does meiotic drive alter male mate preference?

2019 ◽  
Author(s):  
Sam Ronan Finnegan ◽  
Leslie Nitsche ◽  
Matteo Mondani ◽  
M Florencia Camus ◽  
Kevin Fowler ◽  
...  
Keyword(s):  
Low Frequency ◽  
Meiotic Drive ◽  
Mate Preferences ◽  
Mate Preference ◽  
Male Preference ◽  
Male Mate ◽  
A Minor ◽  
The Cost ◽  
Organismal Fitness ◽  
Minor Extent

AbstractMale mate preferences have been demonstrated across a range of species, including the Malaysian stalk-eyed fly, Teleopsis dalmanni. This species is subject to sex-ratio (SR), an X-linked male meiotic driver, which causes the dysfunction of Y-sperm and the production of all-female broods. While there has been work considering female avoidance of meiotic drive males, the mating decisions of drive-bearing males have not been considered previously. Drive males may be less able to bear the cost of choice as SR is associated with a low-frequency inversion that causes reduced organismal fitness. Drive males may also experience weaker selection for preference maintenance if they are avoided by females. Using binary choice trials, across two experiments, we confirmed male preference for large (fecund) females but found no evidence that the strength of male preference differs between drive and standard males. We showed that large eyespan males displayed strong preference for large females, whereas small eyespan males showed no preference. Taken together, these results suggest that, even though meiotic drive is associated with lower genetic quality, it does not directly interfere with male mate preference among available females. However, as drive males tend to have smaller eyespan (albeit only ~5% on average), this will to a minor extent weaken their strength of preference.

scholarly journals Using Population Genetic Theory and DNA Sequences for Species Detection and Identification in Asexual Organisms

PLoS ONE ◽  
2010 ◽  
Vol 5 (5) ◽  
pp. e10609 ◽  
Author(s):  
C. William Birky ◽  
Joshua Adams ◽  
Marlea Gemmel ◽  
Julia Perry
Keyword(s):  
Dna Sequences ◽  
Population Genetic ◽  
Genetic Theory ◽  
Species Detection ◽  
Detection And Identification

Species concepts: a contrast of viewpoints

1996 ◽  
Vol 17 (4) ◽  
pp. 295-301
Author(s):  
Günter Gollmann
Keyword(s):  
Population Genetic ◽  
Species Concepts ◽  
Phylogenetic Species ◽  
Genetic Theory ◽  
Pattern And Process ◽  
Genealogical Concordance ◽  
Evolutionary Genetic

AbstractSome fundamental contrasts underlying the disputes about species concepts are outlined: nominalistic versus essentialistic viewpoints, relations of pattern and process, and incongruities of population genetic, ecological, and phylogenetic approaches. The biological, evolutionary and phylogenetic species concepts are briefly characterized. Attention is drawn to the cohesion concept of species and to genealogical concordance principles, which attempt to integrate elements of those concepts with advances in population biological and evolutionary genetic theory.

scholarly journals COMPARISON BETWEEN RECTAL AND BODY SURFACE TEMPERATURES OBTAINED BY DIGITAL AND NON-CONTACT INFRARED THERMOMETER IN SOME LARGE ANIMAL SPECIES

2019 ◽  
Vol 7 (8) ◽  
pp. 62-68
Author(s):  
Mera Usman Muhammed ◽  
Mayaki Abubakar Musa ◽  
Gambo Abdulrahman Abdullahi
Keyword(s):  
Animal Species ◽  
Large Animal ◽  
Altman Analysis ◽  
Limits Of Agreement ◽  
Infrared Thermometer ◽  
Bland Altman Analysis ◽  
The Face ◽  
Body Temperature Measurement ◽  
The Mean ◽  
The Moment

This study was carried out to compare the digital rectal (DR) thermometer with non-contact infrared thermometer (IRT) measurements at two locations on the face in some large animal species. Two hundred and forty (240) animals comprising of equal numbers of three species (cattle, camel and horses) of varying age and either sex was used. The IR temperature was taken from two sites [frontal (FIRT) and temporal (TIRT) region] on the animal face. The mean IR temperatures (FIRT and TIRT) were higher than the RT in all the animal species. The two thermometers correlate poorly in all the animal species. Bland-Altman analysis showed high biases and limits of agreement not acceptable for clinical purposes. In conclusion, IRT seems to offer a quick and easy way to determine the animal temperature but clinically it cannot be used interchangeably with DR thermometer at the moment for body temperature measurement in these animal species.

scholarly journals Weak epistasis may drive adaptation in recombining bacteria

2017 ◽  
Author(s):  
Brian J Arnold ◽  
Michael Gutmann ◽  
Yonatan Grad ◽  
Sam K Sheppard ◽  
Jukka Corander ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Population Genetic ◽  
Cumulative Effects ◽  
Strong Interactions ◽  
Parameter Estimates ◽  
Metapopulation Dynamics ◽  
Genetic Theory ◽  
Multilocus Model ◽  
Heritable Effects ◽  
The Impact

The impact of epistasis on the evolution of multilocus traits depends on recombination. Population genetic theory has been largely developed for eukaryotes, many of which recombine so frequently that epistasis between polymorphisms has not been considered to play a large role in adaptation and has been compared to the fleeting influence of non-heritable effects. Many bacteria also recombine, some to the degree that their populations are described as 'panmictic' or 'freely recombining'. However, whether this recombination is sufficient to limit the ability of selection to act on epistatic contributions to fitness is unknown. We create a sensitive method to quantify homologous recombination in five bacterial pathogens and use these parameter estimates in a multilocus model of bacterial evolution with additive and epistatic effects. We find that even for highly recombining species (e.g. Streptococcus pneumoniae or Helicobacter pylori), selection may act on the cumulative effects of weak (as well as strong) interactions between distant mutations since homologous recombination typically transfers only short segments. Furthermore, whether selection acts more efficiently on physically proximal loci depends on the average recombination tract length. Epistasis may thus play an important role in the adaptive evolution of bacteria and, unlike in eukaryotes, does not need to be strong, involve near loci, or require specific metapopulation dynamics.

scholarly journals KoT: an automatic implementation of the K/θ method for species delimitation

2021 ◽  
Author(s):  
Yann Spöri ◽  
Fabio Stoch ◽  
Simon Dellicour ◽  
C. William Birky ◽  
Jean-François Flot
Keyword(s):  
Genetic Diversity ◽  
Species Delimitation ◽  
Population Genetic ◽  
Average Distance ◽  
Species Level ◽  
Species Boundaries ◽  
Fasta File ◽  
Genetic Theory ◽  
Putative Species ◽  
The Impact

K/θ is a method to delineate species that rests on the calculation of the ratio between the average distance K separating two putative species-level clades and the genetic diversity θ of these clades. Although this method is explicitly rooted in population genetic theory, it was never benchmarked due to the absence of a program allowing automated analyses. For the same reason, its application by hand was limited to small datasets of a few tens of sequences. We present an automatic implementation of the K/θ method, dubbed KoT (short for "K over Theta"), that takes as input a FASTA file, builds a neighbour-joining tree, and returns putative species boundaries based on a user-specified K/θ threshold. This automatic implementation avoids errors and makes it possible to apply the method to datasets comprising many sequences, as well as to test easily the impact of choosing different K/θ threshold ratios. KoT is implemented in Haxe, with a javascript webserver interface freely available at https://eeg-ebe.github.io/KoT/ .

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