No evidence for reproductive isolation through sexual conflict in the bulb mite Rhizoglyphus robini

Sexual conflict leading to sexual antagonistic coevolution has been hypothesized to drive reproductive isolation in allopatric populations and hence lead to speciation. However, the generality of this speciation mechanism is under debate. We used experimental evolution in the bulb mite Rhizoglyphus robini to investigate whether sexual conflict promotes reproductive isolation measured comprehensively to include all possible pre- and post-zygotic mechanisms. We established replicate populations in which we either enforced monogamy, and hence removed sexual conflict by making male and female evolutionary interests congruent, or allowed promiscuity. After 35 and 45 generations of experimental evolution, we found no evidence of reproductive isolation between the populations in any of the mating systems. Our results indicate that sexual conflict does not necessarily drive fast reproductive isolation and it may not be a ubiquitous mechanism leading to speciation

MORPIIOLOGIC AND ANATOMIC STRUCTURES OF THE EXTRAFLORAL NECTARIES OF THE SWEET CHERRY

International audienc

Biologia kwitnienia i zapylania warzyw baldaszkowych. Część I: Koper ogrodowy (Anethum graveolens L.) [Biology of the bloom and pollination of the umbelliferous vegetables. Part I: Garden dill (Anethum graveolens L.)]

The biology of blooming of garden dill and the influence of insect pollination on seed seetting was investigated. The experiment was carried out near Lublin, on the loessy soils within two different habitats in the season 1977-78. In order to determine the sugar weight of nectar isolated flowers were washed out, then the water enclosed in the nectar was vaporized and the remaining sugars underwent repeated dissolution and determined quantitatively with refractometer. The pollen yield was determined with the ether-weight method. The number of the secreting stomata on the epidermis of the nectary was on the average 950 per 1 mm2. The sugar weight of 0.4 mg and pollen weight of 0.63 mg from 10 flowers informed of the attractiveness ofthe garden dill for the pollinating insects. The estimated honey yield of garden dill was 27.8 kg ha-1 and pollen yield was 18.7 kg ha-1. The isolation of the flowers from the pollinators brought about the decrease of the seed yield of 30% in 1977 and of 43% in 1978. The presence of the entomofauna on the flowers must be taken into consideration when forecasting the seed yield in the horticultural production of the garden dill

On the core curriculum for chemistry – polemically

In 2009, the Ministry of Education introduced new core curricula for preschool education and for general education in different types of schools. The article includes an assessment of new curricula for chemistry after three years of their application to the schooling system in the III and IV stages of education. The evaluation covers both the appropriateness and the aim of changes in curricula, and it also provides specific solutions for various chemistry subdisciplines, such as organic chemistry, physical chemistry, theoretical chemistry and biochemistry. Most attention was given to the level and to the content in teaching chemistry at each stage. Insufficient linkage between chemistry curriculum and other curricula for science, especially for biology and physics, was also analyzed

Schematic representation of the design of Assay II.

<p>Schematic representation of the design of Assay II and the way of calculating mate choice and post-zygotic reproductive isolation on the example of a male’s line 1. Procedures are described in the text.</p

Mate choice and post-zygotic isolation indexes for monogamous and promiscuous mating system.

<p>Mean mate choice and post-zygotic isolation indices for monogamous and promiscuous mating system calculated from the mean indices for male lines. Indices values lower than 0.5 indicate that a female from the same line as a male produces on average more offspring than a female from a different line. Bars indicate 95% confidence intervals.</p

Schematic representation of the design of Assay I.

<p>Schematic representation of the design of Assay I and the way of calculating pre-zygotic isolation mechanisms under male competition index on the example of a female’s line 1. Procedures are described in the text.</p