RESUMEN
The external morphological, X-ray, and tomographic study of a frozen rodent mummy from the Upper Pleistocene Yedoma deposits on the Tirekhtyakh River (a Semyuelyakh River tributary, Abyi ulus, Republic of Sakha (Yakutia), Russia) showed its belonging to Lemmus sp. The radiocarbon age of the finding is 41 305-41 885 cal B.P. This is the first Pleistocene discovery of a frozen mummy of a genus Lemmus representative. In terms of the body and skull sizes, coat color, the lower incisor length, and the molar structure, the specimen studied is similar to the recent Lemmus sibiricus (Kerr, 1792). Comparison of the mitochondrial COB gene sequence with the DNA sequences presented in the GenBank database also testified to the maximum similarity with the Recent Siberian brown lemming.
Asunto(s)
Arvicolinae/anatomía & histología , Fósiles/anatomía & histología , Animales , Arvicolinae/genética , Complejo IV de Transporte de Electrones/genética , Evolución Molecular , SiberiaRESUMEN
It has been found that the optimal body balance control under the conditions of the adaptation to cold is mostly determined by the ratio of the blood concentrations of endogenous ethanol and acetaldehyde related to the activities of liver alcohol dehydrogenase and aldehyde dehydrogenase in the order of increasing level of adaptation: higher vertebrates unadapted to cold, including human â small animals adapted to cold â large animals adapted to cold native to the North â hibernators, regardless of the species specificity and the environment.
Asunto(s)
Aclimatación , Alcohol Deshidrogenasa/sangre , Aldehído Deshidrogenasa/sangre , Evolución Biológica , Hibernación , Alcohol Deshidrogenasa/metabolismo , Aldehído Deshidrogenasa/metabolismo , Animales , Frío , Caballos , Humanos , Hígado/metabolismo , RoedoresRESUMEN
Microbiological and enzyme activities of extrazonal taiga-steppe soils in the lower reaches of the Kolyma River have been studied for the first time. Contrary to north-taiga cryometamorphic soils, predominating in the area, microbial cenoses under herb-sedge petrophytic and grass-sagebrush-herb thermophytic steppes are characterized by features typical for arid soils. The saturation of the soil profile with microorganisms is greater, and the development of actinomycetes is more intensive. The enzyme complex is characterized by high activity of dehydrogenases.
