scholarly journals Having Babies in Soil: Is Sex Really Necessary?

2021 ◽  
Vol 9 ◽  
Author(s):  
Hüsna Öztoprak ◽  
Alexander Brandt ◽  
Marcel D. Solbach ◽  
Jens Bast ◽  
Ina Schaefer
Keyword(s):  
Asexual Reproduction ◽  
Oribatid Mites ◽  
Reading To Learn

Finding a partner and having sex to produce babies is a common way to reproduce. Yet, upon closer look, we see that nature provides many ways for reproduction. What about a world without males? What first sounds impossible is the reality for many organisms that reproduce asexually, meaning without having sex. Females produce daughters that are clones of themselves, so no partner is required and males are dispensable. An Example of such all-female societies are several species of oribatid mites, which live in soils. These mites were already on earth long before the dinosaurs. Have oribatid mites always been asexual? Why do they reproduce without males? Does asexual reproduction have any advantages? Keep reading to learn about asexual reproduction and why oribatid mites are a key organism to investigate the question, “Why sex?”.

To the species composition of oribatid mites (Acari, Oribatida) of Rivnensky Nature Reserve

2019 ◽  
Vol 16 (1) ◽  
pp. 21-24
Author(s):  
O.S. Shevchenko
Keyword(s):  
Species Composition ◽  
Nature Reserve ◽  
Mite Species ◽  
Oribatid Mites ◽  
First Time

New data was added to the oribatid species composition of the Rivnensky Nature Reserve. Overall, 62 mite species were recorded for the territory of research in this study. The species Acrogalumna longipluma, Micreremus brevipes, Licneremaeus licnophorus, Oribatella reticulata, and Porobelba spinosa were not previously listed for the Western Polissia. Of the 60 species of Lower Oribatida mites that have been recorded by other authors in that area, only 18 are found again in the Rivnensky Nature Reserve, indicating that our results are intermediate. A representative of the genus Mainothrus Choi, 1996 (Mainothrus badius (Berlese, 1905)) is found in Ukraine for the first time.

Gemmae in Tetralophozia setiformis (Anastrophyllaceae, Marchantiophyta) and their second record in Eurasia

2017 ◽  
Vol 51 ◽  
pp. 242-250
Author(s):  
M. V. Dulin
Keyword(s):  
British Columbia ◽  
Asexual Reproduction ◽  
Leaf Shape ◽  
Leaf Size ◽  
Komi Republic ◽  
The Other ◽  
Widespread Species ◽  
Northern Urals ◽  
Sexual And Asexual Reproduction ◽  
Murmansk Region

Tetralophozia setiformis is a widespread species occurring usually without organs of sexual and asexual reproduction. Gemmae of Tetralophozia setiformis were observed for the second time in Russia and Eurasia in the Northern Urals, Komi Republic. They form compact masses over upper leaves. The compact masses consist largely (70 %) of immature gemmae. Description of gemmae and gemmiparous shoots from the Northern Urals and their comparison with those from the other known localities, namely British Columbia (Canada) and the Murmansk Region (European Russia) were carried out. The gemmiparous plants of T. setiformis from the Northern Urals have approximately the same width as plants without gemmae but they are shorter. The leaves of gemmiparous plants from the Northern Urals are similar to leaves of gemmiparous plants from British Columbia. The leaf shape in upper part of the gemmiparous shoots varies from the typical to ± modified from gemmae production. These leaf shape transitions include reduction of leaf size and lobe number from 4 to 2–3, suppression of development and disappearance of characteristic teeth at the base of sinus. Gemmae size (17 × 22 μm) of plants from the Northern Urals is within variability recorded for plants from the Murmansk Region and British Columbia.

Molecular basis of adaptive evolution of sperm motility involved in in vivo fertilization of terrestrial animals

Impact ◽  
2020 ◽  
Vol 2020 (6) ◽  
pp. 73-75
Author(s):  
Akihiko Watanabe
Keyword(s):  
Sexual Reproduction ◽  
Sperm Motility ◽  
Asexual Reproduction ◽  
Acrosome Reaction ◽  
Sperm Morphology ◽  
Adaptive Potential ◽  
Selective Pressures ◽  
The Face ◽  
Genetic Profiles

One of the unifying traits of life on this planet is reproduction, or life's ability to make copies of itself. The mode of reproduction has evolved over time, having almost certainly begun with simple asexual reproduction when the ancestral single celled organism divided into two. Since these beginnings' life has tried out numerous strategies, and perhaps one of the most important and successful has been sexual reproduction. This form of reproduction relies on the union of gametes, otherwise known as sperm and egg. Evolutionarily, sexual reproduction allows for greater adaptive potential because the genes of two unique individuals have a chance to recombine and mix in order to produce a new individual. Unlike asexual reproduction which produces genetically-identical clones of the parent individual, sex produces offspring with novel genes and combinations of genes. Therefore, in the face of new selective pressures there is a higher chance that one of these novel genetic profiles will produce an adaptation that is advantageous in the new circumstances. Dr Akihiko Watanabe is a reproductive biologist based in the Department of Biology, Faculty of Science Yamagata University in Japan, he is currently working on three research projects; a comparative study on the signalling pathways for inducing sperm motility and acrosome reaction in amphibians, the mechanism behind the adaptive modification of sperm morphology and motility, and the origin of sperm motility initiating substance (SMIS).

scholarly journals The Advantages of Segregation and the Evolution of Sex

Genetics ◽  
2003 ◽  
Vol 164 (3) ◽  
pp. 1099-1118 ◽  
Author(s):  
Sarah P Otto
Keyword(s):  
Sexual Reproduction ◽  
Asexual Reproduction ◽  
Deleterious Mutations ◽  
Evolution Of Sex ◽  
Beneficial Mutations ◽  
Selection Regime ◽  
Strong Selection ◽  
Genome Wide ◽  
Low Levels

AbstractIn diploids, sexual reproduction promotes both the segregation of alleles at the same locus and the recombination of alleles at different loci. This article is the first to investigate the possibility that sex might have evolved and been maintained to promote segregation, using a model that incorporates both a general selection regime and modifier alleles that alter an individual’s allocation to sexual vs. asexual reproduction. The fate of different modifier alleles was found to depend strongly on the strength of selection at fitness loci and on the presence of inbreeding among individuals undergoing sexual reproduction. When selection is weak and mating occurs randomly among sexually produced gametes, reductions in the occurrence of sex are favored, but the genome-wide strength of selection is extremely small. In contrast, when selection is weak and some inbreeding occurs among gametes, increased allocation to sexual reproduction is expected as long as deleterious mutations are partially recessive and/or beneficial mutations are partially dominant. Under strong selection, the conditions under which increased allocation to sex evolves are reversed. Because deleterious mutations are typically considered to be partially recessive and weakly selected and because most populations exhibit some degree of inbreeding, this model predicts that higher frequencies of sex would evolve and be maintained as a consequence of the effects of segregation. Even with low levels of inbreeding, selection is stronger on a modifier that promotes segregation than on a modifier that promotes recombination, suggesting that the benefits of segregation are more likely than the benefits of recombination to have driven the evolution of sexual reproduction in diploids.

scholarly journals Oribatid mites (Acari, Oribatida) of various habitats in southern Andalusia (Spain)

2010 ◽  
Vol 47 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Stanisław Seniczak ◽  
Anna Seniczak
Keyword(s):  
Species Diversity ◽  
Age Structure ◽  
Coastal Area ◽  
Climatic Conditions ◽  
Oribatid Mites ◽  
Cypress Pine

Oribatid mites (Acari, Oribatida) of various habitats in southern Andalusia (Spain)Oribatid mites were investigated in some habitats (litter under cypress, pine and larch trees, and patches of grasses, mosses and lichens) in southern Andalusia (Spain) in August 2005. The studied communities of oribatid mites were rather poor in terms of abundance and species diversity. The density of mites in cypress litter from the mountains (Granada, Ronda) was distinctly higher than in the coastal area (Benalmádena), which was probably caused by climatic conditions. The Oribatida achieved the highest density in grassy patches in Granada, but most species occurred in cypress litter from Ronda. Among oribatid species,Oribatula frisiaereached the highest density; alsoO. tibialisandHaplochthonius simplexwere relatively abundant. Some species of Oribatida were rich in juveniles, but the age structure of species greatly depended on the kind of litter.

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