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https://en.m.wikipedia.org/wiki/Tiktaalik

eyeless in the fly controlling eye dev.

http://en.wikipedia.org/wiki/PAX6

Perhaps the most interesting, all of the odorant receptors will become pseudogenized in the mammalians aquatically such as dolphins and whales where the nose is demonstrably not used anymore for smelling but becomes the blow hole.

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Induction and organizers[edit]

Spemann was appointed Professor of Zoology and Comparative Anatomy at Rostock in 1908 and, in 1914, Associate Director of the Kaiser Wilhelm Institute of Biology at Dahlem, Berlin. Here he undertook the experiments that would make him famous. Drawing upon the recent work of Warren H. Lewis[2] and Ethel Browne Harvey,[5] he turned his skills to the gastrula, grafting a “field” of cells (the Primitive knot) from one embryo onto another.

The experiments, aided by Hilde Proescholdt (later Mangold), a Ph.D. candidate in Spemann’s laboratory in Freiburg, took place over several years and were published in full only in 1924. They described an area in the embryo, the portions of which, upon transplantation into a second embryo, organized or “induced” secondary embryonic primordia regardless of location. Spemann called these areas “organiser centres” or “organisers”. Later he showed that different parts of the organiser centre produce different parts of the embryo.

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http://en.wikipedia.org/wiki/Hans_Spemann

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von Baer studied the embryonic development of animals, discovering the blastula stage of development and the notochord. Together with Heinz Christian Pander and based on the work by Caspar Friedrich Wolff he described the germ layer theory of development (ectoderm, mesoderm, and endoderm) as a principle in a variety of species, laying the foundation for comparative embryology in the book Über
Entwickelungsgeschichte der Thiere (1828). In 1826 Baer discovered the mammalianovum. The first human ovum was described by Edgar Allen in 1928. In 1827 he completed research Ovi Mammalium et Hominis genesi for Saint-Petersburg’s Academy of Science (published at Leipzig[7][8]) and established that mammals develop from eggs.

He formulated what became known as Baer’s laws of embryology:

General characteristics of the group to which an embryo belongs develop before special characteristics.
General structural relations are likewise formed before the most specific appear.
The form of any given embryo does not converge upon other definite forms, but separates itself from them.
The embryo of a higher animal form never resembles the adult of another animal form, such as one less evolved, but only its embryo.

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http://en.wikipedia.org/wiki/Karl_Ernst_von_Baer

http://en.wikipedia.org/wiki/Zone_of_polarizing_activity

http://en.wikipedia.org/wiki/Tiktaalik