No Arabic abstract
Geophysical and geochemical anomalies may have a mutagenic effect on plants growing in active fault zones being the factors of evolutionary transformation of plant populations. To test this assumption we evaluated the mutation activity of a Lonicera caerulea natural population in one of the active fault zones in the Altai Mountains. We derived principal cytogenetic indices (i.e., mitotic, prophase, metaphase, anaphase, and telophase indices as well as proportion and range of abnormal mitoses) for meristematic cells of Lonicera caerulea seedlings. We found that the local geological and geophysical environment (i.e., mineralogical composition of rocks and anomalies of the magnetic field) increases the mitotic activity and the number of abnormal mitoses in the meristematic cells. The results may help to clarify the role of environmental conditions of tectonically active regions in microevolutionary processes.
The Molnieboi Spur is located at the northwestern margin of the Katun Range, the high-mountain part of the Altai Mountains. Unique geological and geophysical characteristics of the Molnieboi Spur made it an attractive target for complex botanical studies including botanical, soil, geological, geochemical, geophysical, radiation, and soil gas surveys and analyses. In this paper, we present the first version of the geographic information system (GIS) application for the Molnieboi Spur developed using the software QGIS. A digital elevation model for the study area was derived from a detailed topographic map. The database was filled with tabular data on about 100 parameters including: eight botanical characteristics of the Lonicera caerulea local population, two cytogenetic indices of Lonicera caerulea seeds, five types of biochemical parameters of Lonicera caerulea leaves and fruits, three types of geochemical characteristics of the local soils, three types of radiation parameters of the local soils and Lonicera caerulea plants, and one soil gas parameter. The results of the magnetometric survey were inserted as a raster image. A visual analysis of the maps produced allows one to better understand the spatial relationships between various natural components of the Molnieboi Spur.
We compute the allele frequencies of the alpha (B.1.1.7), beta (B.1.351) and delta (B.167.2) variants of SARS-CoV-2 from almost two million genome sequences on the GISAID repository. We find that the frequencies of a majority of the defining mutations in alpha rose towards the end of 2020 but drifted apart during spring 2021, a similar pattern being followed by delta during summer of 2021. For beta we find a more complex scenario with frequencies of some mutations rising and some remaining close to zero. Our results point to that what is generally reported as single variants is in fact a collection of variants with different genetic characteristics. For all three variants we further find some alleles with a clearly deviating time series.
We propose a mathematical model to analyze the time evolution of the total number of infected population with Covid-19 disease at a region in the ongoing pandemic. Using the available data of Covid-19 infected population on various countries we formulate a model which can successfully track the time evolution from early days to the saturation period in a given wave of this infectious disease. It involves a set of effective parameters which can be extracted from the available data. Using those parameters the future trajectories of the disease spread can also be projected. A set of differential equations is also proposed whose solutions are these time evolution trajectories. Using such a formalism we project the future time evolution trajectories of infection spread for a number of countries where the Covid-19 infection is still rapidly rising.
A question in evolutionary biology is why the number of males is approximately equal to that of females in many species, and Fishers theory of equal investment answers that it is the evolutionarily stable state. The Fisherian mechanism can be given a concrete form by a genetic model based on the following assumptions: (1) Males and females mate at random. (2) An allele acts on the father to determine the expected progeny sex ratio. (3) The offspring inherits the allele from either side of the parents with equal probability. The model is known to achieve the 1:1 sex ratio due to the invasion of mutant alleles with different progeny sex ratios. In this study, however, we argue that mutation plays a more subtle role in that fluctuations caused by mutation renormalize the sex ratio and thereby keep it away from 1:1 in general. This finding shows how the sex ratio is affected by mutation in a systematic way, whereby the effective mutation rate can be estimated from an observed sex ratio.
New models for evolutionary processes of mutation accumulation allow hypotheses about the age-specificity of mutational effects to be translated into predictions of heterogeneous population hazard functions. We apply these models to questions in the biodemography of longevity, including proposed explanations of Gompertz hazards and mortality plateaus, and use them to explore the possibility of melding evolutionary and functional models of aging.