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Baer Island in the Kara Sea was named after Karl Ernst von Baer for his important contributions to the research of arctic meteorology between 1830 and 1840. [30] A duck, Baer's pochard, was also named after him. Statue of Karl Ernst von Baer on Toome Hill, Tartu: As a tradition, students wash the statue's head with champagne every Walpurgis ...
In developmental biology, von Baer's laws of embryology (or laws of development) are four rules proposed by Karl Ernst von Baer to explain the observed pattern of embryonic development in different species. [1] von Baer formulated the laws in his book On the Developmental History of Animals (German: Über Entwickelungsgeschichte der Thiere ...
Embryology theories of Ernst Haeckel, who argued for recapitulation [3] of evolutionary development in the embryo, and Karl Ernst von Baer's epigenesis. A recapitulation theory of evolutionary development was proposed by Étienne Serres in 1824–26, echoing the 1808 ideas of Johann Friedrich Meckel.
Aristotle proposed the theory that is now accepted, epigenesis. Epigenesis is the idea that organisms develop from seed or egg in a sequence of steps. Modern embryology developed from the work of Karl Ernst von Baer, though accurate observations had been made in Italy by anatomists such as Aldrovandi and Leonardo da Vinci in the Renaissance.
The theory of recapitulation, also called the biogenetic law or embryological parallelism—often expressed using Ernst Haeckel's phrase "ontogeny recapitulates phylogeny"—is a historical hypothesis that the development of the embryo of an animal, from fertilization to gestation or hatching (), goes through stages resembling or representing successive adult stages in the evolution of the ...
Ernst Haeckel, along with Karl von Baer and Wilhelm His, are primarily influential in forming the preliminary foundations of 'phylogenetic embryology' based on principles of evolution. [4] Haeckel's 'Biogenetic Law' portrays the parallel relationship between an embryo's development and phylogenetic history.
Among the earliest biological rules in modern times are those of Karl Ernst von Baer (from 1828 onwards) on embryonic development (see von Baer's laws), [4] and of Constantin Wilhelm Lambert Gloger on animal pigmentation, in 1833 (see Gloger's rule). [5] There is some scepticism among biogeographers about the usefulness of general rules.
The theory that located the homonculus in the egg was called ovism. But, when spermatozoa were discovered, a rival camp of spermists sprang up, claiming that the homunculus must come from the male. In fact, the term "spermatozoon," coined by Karl Ernst von Baer, means "seed animals." [4]