Pethia didi markings rather than one. Pethia didi Pethia didi is a species of cyprinid fish which has only been recorded in the vicinity of Myitkyina and Indawgyi Lake in the north of Myanmar. This is a small fish which can reach a length of SL. It is generally brownish with a dark vertical bar just behind the operculum and a round dark blotch on the caudal peduncle. The species "P. tiantian" – with a range close to "P. didi" – is similarly marked, but "P. didi" can be distinguished by its truncated lateral line, deeper body and longer dorsal fin, with
History of model organisms respective work on natural selection and the genetics of heredity. These early works in finding standards to compare organisms against continued into the 20th century as the first model organisms were brought into laboratories. Beginning in the early 1900s "Drosophila" entered the research laboratories and opened up the doors for other model organisms like Tobacco mosaic virus, E. coli, C57BL/6 (lab mice), etc. These organisms have led to many advances in the past century. Some of the first work with what would be considered model organisms started because Gregor Johann Mendel felt that the views of Darwin were insufficient in