Doctor Strange expands the scope of the Marvel Studios film series. Characters regularly talk about the βmultiverse,β a concept tragically central to basically every major mainstream comic book story of the last few decades. And characters frequently take far-out trips to outer realms of sub-reality, into dark macro-micro dimensions beyond space and time. Coming in at the midpoint of the MCUβs Phase 3, Strange marks an important step outward, establishing some core concepts that may point toward the megafranchiseβs future.
brown rat, (Rattus norvegicus), species of rat found on every continent except Antarctica. The alternate name βNorway ratβ came from a false hypothesis widely believed in 18th-century England that the rats were native to Norway. Research has confirmed, however, that the brown rat is native to Asia, specifically northern China or Mongolia. Outside its native region the brown rat is a largely disliked pest and an invasive species, though the animal is widely used in biomedical research and is sometimes kept as a pet.
The brown rat may weigh up to 0.5 kg (about 1 pound), twice as much as the average house rat (Rattus rattus), with males typically weighing more than females. The fur is most often gray or brown with a lighter face and underside; domesticated brown rats can also be white or mottled. Their long tails are covered in a thin layer of fur and are thus frequently mistaken as bald. The length of the tail often comes close to the length of the body.
It is thought that as agriculture developed in China, brown rats began living close to farms, where a consistent source of food was present. From there, the species likely spread gradually to southeastern Asia, then north to Japan and Russia, before moving westward to Europe by the mid-1500s. Scientists have theorized that as Western Europe colonized other parts of the world, the brown rat followed. The animals likely reached North America about 1750. According to recent research on rats in New York City, most brown rats living in the eastern United States, South America, Africa, and New Zealand descended from the rats of Western Europe. Scientists were surprised by the lack of genetic diversity in the New York City rats; it seemed as though even if brown rats were arriving from elsewhere on ships and other transport, the established population of rats were rejecting the newcomers aggressively enough that these foreign communities could not thrive. This aggression has likely aided brown rats in their global spread as an invasive species.
Brown rats are widely considered to be the first mammal domesticated for laboratory research. It was in 19th century Europe that brown rats were first used for research purposes; they were a suitable choice for research due to their abundance and negative reputation. Since then, laboratory rats have become integral to biomedical research. They differ in appearance from wild brown ratsβlaboratory rats are often albino, or white with red eyesβand in behavior, as laboratory rats are more docile than the wild brown rat.
Rats are members of the rodent family and the genus Rattus. Currently, there are more than 60 species of rats around the world, and the most common is the brown rat (Rattus norvegicus), also known as the Norway rat.