Emil Selenka (Braunschweig, February 27, 1842 - Munich, February 20, 1902) was a German zoologist. He is known for his research on invertebrates and apes and the scientific expeditions he organized to Southeast Asia and South America.
Selenka was the son of bookbinder Johannes Selenka (1801-1871). He studied natural history at the University of Göttingen, and following his dissertation on Holothuroidea, he remained in Göttingen as an assistant to Wilhelm Moritz Keferstein (1833-1870). His research was in this period mainly on the anatomy, taxonomy and embryology of marine invertebrates, especially organisms from the phylum Echinodermata. In 1868 he became a professor of zoology and comparative anatomy at the University of Leiden, and in 1874 relocated to the University of Erlangen. In 1895 he was given an honorary professorship at the University of Munich. He was co-founder of the journal Biologisches Zentralblatt.
His later research was on mammals. He studied the early development of the embryo and the development of the germ layer in mammals, and did comparative anatomic research on apes, especially gibbons and orangutans. He found evidence that the lateral distribution of orangutan races was caused by geographic isolation (a process called allopatric speciation). Selenka also examined the evolution of marsupials and their morphologic relation with reptiles. One problem he was intereted in, was the evolutionary relation between Australian and South American marsupials.
To collect material Selenka organized expeditions to tropical countries. In 1877 he undertook an expedition to Brasil. From 1892 he led an expedition that lasted two years to Southeast Asia, it visited Ceylon, the Dutch East Indies, Japan, China and Australia. Among the participants was his second wife, the zoologist and feminist Margarethe Selenka (1860-1922), with whom he was married in 1893. When Selenka became severely ill during his stay in the Dutch East Indies and had to return to Germany, his wife continued exploring the jungles of Borneo by herself. The couple wrote a report of their journeys together, titled Sonnige Welten- Ostasiatische Reiseskizzen. Other publications by Emil Selenka are: