Haeckel ’ s ‘ Biogenetic Law ’ portrays the parallel relationship between an embryo ’ s development and phylogenetic history.

Although the early embryos of different species exhibit similarities, Haeckel apparently exaggerated these similarities in support of his Recapitulation theory, sometimes known as the Biogenetic Law or " Ontogeny recapitulates phylogeny ".

Haeckel ’ s illustrations show vertebrate embryos at different stages of development, which exhibit embryonic resemblance as support for evolution, recapitulation as evidence of the Biogenetic Law, and phenotypic divergence as evidence of von Baer ’ s laws.

Haeckel ’ s embryo drawings are primarily intended to express his idiosyncratic theory of embryonic development, the Biogenetic Law, which in turn assumes ( but is not crucial to ) the evolutionary concept of common descent.

The term, ‘ recapitulation ,’ has come to embody Haeckel ’ s Biogenetic Law, for embryonic development is a recapitulation of evolution.

Despite the numerous oppositions, Haeckel has influenced many disciplines in science in his drive to integrate such disciplines of taxonomy and embryology into the Darwinian framework and to investigate phylogenetic reconstruction through his Biogenetic Law.

Rather than being a strict Darwinian, Haeckel believed that racial characteristics were acquired through interactions with the environment and that ontogeny directly followed phylogeny.

Haeckel proposes that all classes of vertebrates pass through an evolutionarily conserved “ phylotypic ” stage of development, a period of reduced phenotypic diversity among higher embryos.

His also accuses Haeckel of creating early human embryos that he conjured in his imagination rather than obtained through empirical observation.

German biologist Ernst Haeckel popularized medusae through his vivid illustrations, particularly in Kunstformen der Natur.

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.

late 20th and early 21st century critics, Jonathan Wells and Stephen Jay Gould, have objected to the continued use of Haeckel ’ s embryo drawings in textbooks.

The series of twenty-four embryos from the early editions of Haeckel ’ s Anthropogenie remain the most famous.

Similarities can be seen along the first two rows ; the appearance of specialized characters in each species can be seen in the columns and a diagonal interpretation leads one to Haeckel ’ s idea of recapitulation.

As a response to Haeckel ’ s theory of recapitulation, von Baer enunciates his most notorious laws of development.

Wilhelm His was one of Haeckel ’ s most authoritative and primary opponents advocating physiological embryology.

His ’ depiction of embryological development strongly differs from Haeckel ’ s depiction, for His argues that the phylogenetic explanation of ontogenetic events is unnecessary.

Although Haeckel is proven right about the allantois, the utilization of Krause ’ s embryo as justification turns out to be problematic, for the embryo is that of a bird rather than a human.

In response to Haeckel ’ s evolutionary claim that all vertebrates are essentially identical in the first month of embryonic life as proof of common descent, His responds by insisting that a more skilled observer would recognize even sooner that early embryos can be distinguished.

Haeckel ’ s opponents believe that he de-emphasizes the differences between early embryonic stages in order to make the similarities between embryos of different species more pronounced.

Although Rutimeyer did not denounce Haeckel ’ s embryo drawings as fraud, he argued that such drawings are manipulations of public and scientific thought.

As a pioneer in mammalian embryology, he was one of Haeckel ’ s strongest critics.

Nevertheless, Bischoff ’ s main argument was in reference to Haeckel ’ s drawings of human embryos, for Haeckel is later accused of miscopying the dog embryo from him.

Haeckel promoted and popularized Charles Darwin's work in Germany and developed the controversial recapitulation theory (" ontogeny recapitulates phylogeny ") claiming that an individual organism's biological development, or ontogeny, parallels and summarizes its species ' evolutionary development, or phylogeny.

Haeckel advanced a version of the earlier " recapitulation theory ", previously set out by Étienne Serres in the 1820s and supported by followers of Geoffroy including Robert Edmond Grant, which proposed a link between ontogeny ( development of form ) and phylogeny ( evolutionary descent ), summed up by Haeckel in the phrase " ontogeny recapitulates phylogeny ".

While often seen as rejecting Darwin's theory of branching evolution for a more linear Lamarckian " biogenic law " of progressive evolution, this is not accurate: Haeckel used the Lamarckian picture to describe the ontogenic and phylogenic history of the individual species, but agreed with Darwin about the branching nature of all species from one, or a few, original ancestors.

Haeckel formulated his theory as " Ontogeny recapitulates phylogeny ".

He compactly expressed the basis for a cultural recapitulation theory of education in the following claim, published in 1861, five years before Haeckel first published on the subject:

Haeckel used embryology extensively in his recapitulation theory, which embodied a progressive, almost linear model of evolution.

Historians write that most such political and economic commentators had only a superficial understanding of Darwin's scientific theory, and were as strongly influenced by other concepts about social progress and evolution, such as the Lamarckian ideas of Spencer and Haeckel, as they were by Darwin's work.

The concept of a biotope was first advocated by Ernst Haeckel ( 1834-1919 ): a German zoologist famous for the recapitulation theory.

Ernst Haeckel ( 1866 ), in his endeavour to produce a synthesis of Darwin's theory with Lamarckism and Naturphilosophie, proposed that " ontogeny recapitulates phylogeny ," that is, the development of the embryo of every species ( ontogeny ) fully repeats the evolutionary development of that species ( phylogeny ), in Geoffroy's linear model rather than Darwin's idea of branching evolution.

* Konrad Körner: Linguistics and evolution theory ( Three essays by August Schleicher, Ernst Haeckel and Wilhelm Bleek ).

Ernst Haeckel ( 1834 – 1919 ) became famous for his " recapitulation theory ", according to which each individual mirrors the evolution of the whole species during his life.

In the latter 19th century, the department of zoology taught evolutionary theory, with Carl Gegenbaur, Ernst Haeckel and others publishing detailed theories at the time of Darwin's " Origin of Species " ( 1858 ).

This important refutation of both preformation and the mosaic theory of Wilhelm Roux was to be subject to much discussion in the ensuing years, and caused friction among Driesch, Roux and Haeckel.

As a professor of anatomy at the University of Jena ( 1855 – 1873 ) and at the University of Heidelberg ( 1873 – 1903 ), Carl Gegenbaur was a strong supporter of Charles Darwin's theory of organic evolution, having taught and worked, beginning in 1858, with Ernst Haeckel, 8 years his junior.

Haeckel, in his book The History of Creation, devoted most of a chapter to the argument, and ended by proposing, perhaps with tongue slightly in cheek, to set up " a theory of the unsuitability of parts in organisms, as a counter-hypothesis to the old popular doctrine of the suitability of parts " (, p. 331 ).

This is the idea propagated by Ernst Haeckel as a source of evolutionary evidence ( recapitulation theory ).

Recent molecular and morphologic data add increasing evidence against this view, and the alternative colonial theory, also proposed by Haeckel in the 1870s is gaining widespread acceptance.

Haeckel, who admired Darwin's work, defined ecology in reference to the economy of nature, which has led some to question whether ecology and the economy of nature are synonymous.

Haeckel introduced the concept of " heterochrony ", which is the change in timing of embryonic development over the course of evolution.

In addressing his embryo drawings to a general audience, Haeckel does not cite any sources, which gives his opponents the freedom to make assumptions regarding the originality of his work.

Haeckel then provided a means of pursuing this aim with his biogenetic law, in which he proposed to compare an individual's various stages of development with its ancestral line.

German naturalist Ernst Haeckel proposed a monistic pantheism in which the idea of God is identical with that of nature or substance.

Early twentieth-century biologists like Ernst Haeckel viewed embryology as a recapitulation of evolution, which implies a kind of organising memory, and a few modern biologists, such as Rupert Sheldrake, influenced by Jungian ideas and by vitalism, have posited organising fields of life consisting of memories and drives.

Yet, in our times, scientific hylozoism – whether modified, or keeping the trend to make all beings conform to some uniform pattern, to which the concept was adhered in modernity by Herbert Spencer, Hermann Lotze, and Ernst Heinrich Haeckel – was often called upon as a protest against a mechanicistic view of the world.

In what was to be the last decade of his life, he penned works such as Parsifal Unveiled, which details the esoteric symbolism of the Wagner opera, and Gnostic Anthropology in which he heavily criticizes the theories of Darwin, Haeckel, " and their followers ".

Haeckel later abandoned this idea which is revived by Hadzi in 1953.

In contrast to most of Darwin's supporters, Ernst Haeckel put forward a doctrine of evolutionary polygenism based on the ideas of the linguist and polygenist August Schleicher, in which several different language groups had arisen separately from speechless prehuman Urmenschen, which themselves had evolved from simian ancestors.

Haeckel divided human beings into ten races, of which the Caucasian was the highest and the primitives were doomed to extinction.

Ernst Haeckel claimed that Negroes have stronger and more freely movable toes than any other race which is evidence that Negroes are connected to apes because when apes stop climbing in trees they hold on to the trees with their toes, Haeckel compared Negroes to “ four-handed ” apes.

Ehret was a proponent of the emerging back-to-nature renaissance in Germany and Switzerland during the latter part of the 19th century, which was inspired by writers such as Meister Eckhart, Christoph Wilhelm Hufeland, Nietzche, Goethe, Herman Hesse, Ernst Haeckel and Eduard Baltzer as well as the healing traditions of Roman and Greek philosophers such as Paracelsus, Empedocles, Seneca, Plutarch, Porphyry, Galen, Hippocrates, Socrates, Pythagoras, Plato and Aristotle.

In modern biology ( e. g. Haeckel and Fritz Müller ), palingenesis has been used for the exact reproduction of ancestral features by inheritance, as opposed to kenogenesis, in which the inherited characteristics are modified by environment.