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Bacteria exhibit three different types of asymmetry: conditional asymmetry, reproductive asymmetry, and morphological asymmetry. [2] Conditional asymmetry is well defined in the case of endospore formation, which is triggered by stressful environmental conditions such as increased heat, pH change, and nutrient depletion.
In a study conducted in Queensland, Australia, for example, populations of two amphibian species, Litoria nannotis and Litoria genimaculata, were found to exhibit far greater levels of limb asymmetry in pre-decline years than in control years, the latter of which preceded die offs by an average of 16 years.
Genetic erosion in agricultural and livestock is the loss of biological genetic diversity – including the loss of individual genes, and the loss of particular recombinants of genes (or gene complexes) – such as those manifested in locally adapted landraces of domesticated animals or plants that have become adapted to the natural environment in which they originated.
An asymmetric cell division produces two daughter cells with different cellular fates. This is in contrast to symmetric cell divisions which give rise to daughter cells of equivalent fates. Notably, stem cells divide asymmetrically to give rise to two distinct daughter cells: one copy of the original stem cell as well as a second daughter ...
An example of fully asymmetric apparent competition which often occurs near urban centers is subsidies in the form of human garbage or waste. In the early 2000s, the common raven ( Corvus corax ) population in the Mojave Desert increased due to an influx of human garbage, leading to an indirect negative effect on juvenile desert tortoises ...
Classical examples of polarized cells are described below, including epithelial cells with apical-basal polarity, neurons in which signals propagate in one direction from dendrites to axons, and migrating cells. Furthermore, cell polarity is important during many types of asymmetric cell division to set up functional asymmetries between ...
Competition among plants for light is size-asymmetric because of the directionality of its supply. [2] Higher leaves shade lower leaves but not vice versa. Competition for nutrients appears to be relatively size-symmetric, [9] although it has been hypothesized that a patchy distribution of nutrients in the soil may lead to size asymmetry in competition among roots.
Fluctuating asymmetry (FA) is often considered to be the product of developmental stress and instability, caused by both genetic and environmental stressors. The notion that FA is a result of genetic and environmental factors is supported by Waddington's notion of canalisation, which implies that FA is a measure of the genome's ability to successfully buffer development to achieve a normal ...