Although Haeckel stressed comparative embryology and Gegenbaur promoted the comparison of adult structures, both believed that the two methods could work in conjunction to produce the goal of evolutionary morphology.

On the other hand, it does seem likely that Marr was influenced by Ernst Haeckel, a professor who popularized the notion of Social Darwinism among Germany's educated classes.

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

The term " dysteleology " is a modern word invented and popularized by Ernst Haeckel.

From 1866 to 1867, Haeckel made an extended journey to the Canary Islands with Hermann Fol and during this period, met with Charles Darwin, in 1866 at Down House in Kent, Thomas Huxley and Charles Lyell.

Ernst Haeckel attempted to synthesize the ideas of Lamarckism and Goethe's Naturphilosophie with Charles Darwin's concepts.

Modern embryological pioneers include Charles Darwin, Ernst Haeckel, J. B. S.

* Robert J. Richards, The Linguistic Creation of Man: Charles Darwin, August Schleicher, Ernst Haeckel, and the Missing Link in Nineteenth-Century Evolutionary Theory.

Baruch Spinoza, Gottfried Leibniz, Gustav Theodor Fechner, Friedrich Paulsen, Ernst Haeckel, Charles Strong, and partially William James are considered panpsychists.

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.

Ernst Haeckel expanded on the ideas of Gegenbaur while advocating the concepts of Charles Darwin.

This circle enthusiastically read the works of Ernst Haeckel and Charles Darwin.

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.

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 showed a main trunk leading to mankind with minor branches to various animals, unlike Darwin's branching evolutionary tree.

Ernst Haeckel was particularly ardent, aiming to synthesise Darwin's ideas with those of Lamarck and Goethe while still reflecting the spirit of Naturphilosophie.

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.

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.

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 ).

His ideas changed in summer 1862 when he returned to study at Jena, where Ernst Haeckel introduced him to Darwin's work and theories.

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.

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.

The terms " gastrula " and " gastrulation " were coined by Ernst Haeckel, in his 1872 work " Biology of Calcareous Sponges ".

In Phylum, Rockman draws upon the work of Ernst Haeckel, a proponent of Darwinism.

During these times, he worked several times at facilities located by the sea: Heligoland alongside Haeckel in 1865, Hamburg in 1866, Millport, Scotland with David Robertson in 1867 and 1868 and moved to Messina, Italy, during the winter of 1868 together with his friend and colleague Nicholas Miklouho-Maclay to work on the marine life of the Straits of Messina.

Darwin told Haeckel " I doubt whether my strength will last for much more serious work.

Darwin was visited in October 1866 by the zoologist Ernst Haeckel, who over the years had built support for Darwin in Germany, now getting huge classes at Jena for his lectures on Darwinismus.

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.

Roux was born and educated in Jena, Germany where he attended university and studied under Ernst Haeckel.

In the 19th century, Haeckel developed a materialist form of hylozoism, specially against Rudolf Virchow's and Hermann von Helmholtz's mechanical views of humans and nature.

The word " tectology " was developed by Ernst Haeckel, but Bogdanov used it for a different purpose.

Romanes's 1892 copy of Ernst Haeckel's controversial embryo drawings ( this version of the figure is often attributed incorrectly to Haeckel ).

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 ".

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.

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.

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

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

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.

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

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.

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.

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