Oskar Hertwig (April 21, 1849, Friedberg, Hessen - October 25, 1922, Berlin) was a German zoologist. He was the brother of zoologist Richard Hertwig (September 23, 1850, Friedberg - October 3, 1937, Schlederloh/Munich). Jump to: navigation, search April 21 is the 111th day of the year in the Gregorian calendar (112th in leap years). ... 1849 was a common year starting on Monday (see link for calendar). ... Friedberg is the name of two cities in Germany and one in Austria: Friedberg, Bavaria Friedberg, Hesse Friedberg, Styria This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... Hesse is also the name of the German writer Hermann Hesse, as well as the German mathematician Otto Hesse. ... Jump to: navigation, search October 25 is the 298th day of the year (299th in leap years) in the Gregorian Calendar, with 67 days remaining. ... Jump to: navigation, search 1922 was a common year starting on Sunday (see link for calendar). ... Jump to: navigation, search Berlin â–¶(?), IPA: , is the capital of Germany and its largest city; the city is now home to 3. ... Zoology (Greek zoon = animal and logos = word) is the biological discipline which involves the study of animals. ... Jump to: navigation, search September 23 is the 266th day of the year (267th in leap years). ... Jump to: navigation, search 1850 was a common year starting on Tuesday (see link for calendar). ... Friedberg is the name of two cities in Germany and one in Austria: Friedberg, Bavaria Friedberg, Hesse Friedberg, Styria This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... Jump to: navigation, search October 3 is the 276th day of the year (277th in Leap years). ... Jump to: navigation, search 1937 was a common year starting on Friday (link will take you to calendar). ... Jump to: navigation, search For the 2005 Steven Spielberg film, see Munich (film). ...

The Hertwig brothers were the most eminent scholars of Ernst Haeckel. They were independent of Haeckel's philosophical speculations but took his stimulations in a positive way to widen their concepts in zoology. Initially, between 1879-1883, they performed embryological studies, especially on the theory of the coelom (1881).These problems were based on the phylogenetic theorems of Haeckel, i.e. the biogenic theory (German = biogenetisches Grundgesetz), and the "gastraea theory". Richard Hertwig became a professor of Zoology in 1885 in Munich while Oskar became a professor of anatomy in 1888 in Berlin. Richards research focused on protists (the relationship between the nucleus and the plasm = "Kern-Plasma-Relation")as well as on developmental physiological studies on sea urchins and frogs. He also wrote a leading Zoology textbook. Oskar Hertwig was a leader in the field of comparative and causal animal-developmental history. He also wrote a leading textbook. He discovered fertilization of sea urchins, he recognized the role of the cell nucleus during inheritance and chromosome reduction during meiosis: 1876 he found that fertilization includes the penetration of a spermatozoon into an egg cell. While Oskar was well interested in developmental biology he was opposed to chance as assumed in Charles Darwin´s theory. His most important theoretical book was: "Das Werden der Organismen, eine Widerlegung der Darwinschen Zufallslehre" (Jena 1916)(transl.: The Origin of Organisms - a Refutation of Darwin´s Theory of Chance"). Ernst Haeckel Ernst Heinrich Philipp August Haeckel (February 16, 1834 - August 8, 1919), also written von Haeckel, was a German biologist and philosopher who popularized Charles Darwins work in Germany. ... In biology, a law stating that the earlier stages of embryos of species advanced in the evolutionary process, such as humans, resemble the embryos of ancestral species, such as fish. ... Jump to: navigation, search In his lifetime Charles Darwin gained international fame as a controversial and influential scientist. ...

References:

• 1. Cremer, T. 1985. Von der Zellenlehre zur Chromosomentheorie. Springer Vlg., Heidelberg.
• 2. Krafft, F., and A. Meyer-Abich (ed.). 1970. Große Naturwissenschaftler - Biographisches Lexikon. Fischer Bücherei GmbH, Frankfurt a.M. & Hamburg.
• 3. Mol.Cell.Biol.-lecture, Heidelberg, D.-H. Lankenau.Early to recent key-discoveries: From Germline Theory to Modern Gene Modification

Links

• Epigenetics
• Oskar Hertwig Portrait