Ciekawostka: A polar bears skin is black

Evidence: 55 • authority: 92

Recent Dominant Transposition Events Affect Gene Regulatory Regions, but Not Coding Sequences, in Polar and Brown Bear Genomes.. Transposable elements (TEs) are inserted into the genome and may change its properties; those occurring in or near regulatory regions may also alter gene expression. Given the challenges of detecting insertions in short-read sequencing, we analyzed structural variants in polar and brown bear genomes by a reciprocal alignment of one species' sample genomes to a reference sequence of the other species, thus inferring TE insertion as the other genome's "deletions". With this approach, we detected short interspersed elements (SINEs) belonging to the CAN SINE family as…

Evidence: 52 • authority: 88

Polar Bear vs Grizzly bear. Polar bears Polar bears are large carnivorous mammals that inhabit the Arctic regions of the world. They are well adapted to living in a cold and icy environment, with thick fur, a layer of insulating blubber, and large, webbed paws that allow them to swim and walk on snow and ice. Polar bears are apex predators, meaning they are at the top of the food chain in their ecosystem.

Evidence: 52 • authority: 88

Polar Bear vs Grizzly bear. Polar bears Polar bears are large carnivorous mammals that inhabit the Arctic regions of the world. They are well adapted to living in a cold and icy environment, with thick fur, a layer of insulating blubber, and large, webbed paws that allow them to swim and walk on snow and ice. Polar bears are apex predators, meaning they are at the top of the food chain in their ecosystem.

Evidence: 52 • authority: 72

Bears are carnivoran mammals of the family Ursidae (). They are classified as caniforms within the suborder Caniformia. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats throughout most of the Northern Hemisphere and partially in the Southern Hemisphere. Bears are found on the continents of North America, South America, and Eurasia. Common characteristics of modern bears include large bodies with stocky legs, long snouts, small rounded ears, shaggy hair, plantigrade paws with five nonretractile claws, and short tails. While the polar bear is mostly carnivorous, and the giant panda is mostly herbivorous, the remaining six species ar…

Evidence: 43 • authority: 72

The wildlife of Alaska is both diverse and abundant. The Alaskan Peninsula provides an important habitat for fish, mammals, reptiles, and birds. At the top of the food chain are the bears. Alaska contains about 70% of the total North American brown bear population and the majority of the grizzly bears, as well as black bears and Kodiak bears. In winter, polar bears can be found in the Kuskokwim Delta, St. Matthew Island, and at the southernmost portion of St. Lawrence Island. Other major mammals include moose and caribou, bison, wolves and wolverines, foxes, otters and beavers. Fish species are extensive, including: salmon, graylings, char, rainbow and lake trout, northern pike, halibut, po…

Evidence: 41 • authority: 92

Chromosome-scale Genomes Show Rapid Diversification and Ancient Gene Flow Among Bear Species.. Reconstructions of evolutionary history can be restricted by a lack of high-quality reference genomes. To date, only four of the eight species of bears (family Ursidae) have chromosome-level genome assemblies. Here, we present assemblies for three additional species-the sun, sloth, and Andean bears-and use a whole-genome alignment of all bear species and other carnivores to reconstruct the evolution of Ursidae. Multiple divergence dating approaches suggest that the six Ursine bears likely diversified in the last 5 Ma, but that divergence times within Ursinae are significantly impacted by gene tree…

Evidence: 41 • authority: 92

Whole-Genome Sequencing Revealed Local Genetic Differences and Multi-Layered Genetic Structure in Asian Brown Bear (Ursus arctos) Populations.. A multi-layered genetic structure shaped by multiple demographic events across different time periods has been well documented in some species. However, evaluating this pattern remains challenging in many wide-ranging wildlife because genome-wide datasets with broad geographic coverage are still scarce. Brown bears are genetically differentiated among regional populations, but the genomic data are still limited and the demographic events remain incompletely understood. Here, we generated whole-genome resequencing data from brown bears in Asian local…

Evidence: 41 • authority: 72

Light skin is a human skin color that has a low level of eumelanin pigmentation as an adaptation to environments of low UV radiation. Due to migrations of people in recent centuries, light-skinned populations today are found all over the world. Light skin is most commonly found amongst the native populations of Europe, East Asia, West Asia, Central Asia, Indian subcontinent, Siberia, and North Africa as measured through skin reflectance. People with light skin pigmentation are often referred to as "white", but the majority of countries officially categorize people by ethnic or national origin and not by perceived skin tone. Furthermore, definitions and perceptions of "ethnicity" or "race" v…

Evidence: — • authority: 35