Orthogenesis

Orthogenesis is an obsolete biological hypothesis that organisms have an innate tendency to evolve in a definite direction towards some goal, due to some internal mechanism or "driving force". According to the theory, the largest-scale trends in evolution have an absolute goal such as increasing biological complexity. Prominent historical figures who have championed some form of evolutionary progress include Jean-Baptiste Lamarck, Pierre Teilhard de Chardin, and Henri Bergson.
The term orthogenesis was introduced by Wilhelm Haacke in 1893 and popularized by Theodor Eimer five years later. Proponents of orthogenesis had rejected the theory of natural selection as the organizing mechanism in evolution for a rectilinear model of directed evolution. With the emergence of the modern synthesis, in which genetics was integrated with evolution, orthogenesis and other alternatives to Darwinism were largely abandoned by biologists, but the notion that evolution represents progress is still widely shared; modern supporters include E. O. Wilson and Simon Conway Morris. The evolutionary biologist Ernst Mayr made the term effectively taboo in the journal Nature in 1948, by stating that it implied "some supernatural force". The American paleontologist George Gaylord Simpson attacked orthogenesis, linking it with vitalism by describing it as "the mysterious inner force". Despite this, many museum displays and textbook illustrations continue to give the impression that evolution is directed.
The philosopher of biology Michael Ruse notes that in popular culture, evolution and progress are synonyms, while the unintentionally misleading image of the March of Progress, from apes to modern humans, has been widely imitated.

Definition

The term orthogenesis was first used by the biologist Wilhelm Haacke in 1893. Theodor Eimer was the first to give the word a definition; he defined orthogenesis as "the general law according to which evolutionary development takes place in a noticeable direction, above all in specialized groups".
In 1922, the zoologist Michael F. Guyer wrote:
According to Susan R. Schrepfer in 1983:
In 1988, Francisco J. Ayala defined progress as "systematic change in a feature belonging to all the members of a sequence in such a way that posterior members of the sequence exhibit an improvement of that feature". He argued that there are two elements in this definition, directional change and improvement according to some standard. Whether a directional change constitutes an improvement is not a scientific question; therefore Ayala suggested that science should focus on the question of whether there is directional change, without regard to whether the change is "improvement". This may be compared to Stephen Jay Gould's suggestion of "replacing the idea of progress with an operational notion of directionality".
In 1989, Peter J. Bowler defined orthogenesis as:
In 1996, Michael Ruse defined orthogenesis as "the view that evolution has a kind of momentum of its own that carries organisms along certain tracks".

History

Medieval

The possibility of progress is embedded in the mediaeval great chain of being, with a linear sequence of forms from lowest to highest. The concept, indeed, had its roots in Aristotle's biology, from insects that produced only a grub, to fish that laid eggs, and on up to animals with blood and live birth. The medieval chain, as in Ramon Lull's Ladder of Ascent and Descent of the Mind, 1305, added steps or levels above humans, with orders of angels reaching up to God at the top.

Pre-Darwinian

The orthogenesis hypothesis had a significant following in the 19th century when evolutionary mechanisms such as Lamarckism were being proposed. The French zoologist Jean-Baptiste Lamarck himself accepted the idea, and it had a central role in his theory of inheritance of acquired characteristics, the hypothesized mechanism of which resembled the "mysterious inner force" of orthogenesis. Orthogenesis was particularly accepted by paleontologists who saw in their fossils a directional change, and in invertebrate paleontology thought there was a gradual and constant directional change. Those who accepted orthogenesis in this way, however, did not necessarily accept that the mechanism that drove orthogenesis was teleological. Charles Darwin himself rarely used the term "evolution" now so commonly used to describe his theory, because the term was strongly associated with orthogenesis, as had been common usage since at least 1647. His grandfather, the physician and polymath Erasmus Darwin, was both progressionist and vitalist, seeing "the whole cosmos a living thing propelled by an internal vital force" towards "greater perfection". Robert Chambers, in his popular anonymously published 1844 book Vestiges of the Natural History of Creation presented a sweeping narrative account of cosmic transmutation, culminating in the evolution of humanity. Chambers included detailed analysis of the fossil record.

With Darwin

Ruse observed that "Progress became essentially a nineteenth-century belief. It gave meaning to life—it offered inspiration—after the collapse of the foundations of the past."
The Baltic German biologist Karl Ernst von Baer argued for an orthogenetic force in nature, reasoning in a review of Darwin's 1859 On the Origin of Species that "Forces which are not directed—so-called blind forces—can never produce order."
In 1864, the Swiss anatomist Albert von Kölliker presented his orthogenetic theory, heterogenesis, arguing for wholly separate lines of descent with no common ancestor.
In 1884, the Swiss botanist Carl Nägeli proposed a version of orthogenesis involving an "inner perfecting principle". Gregor Mendel died that same year; Nägeli, who proposed that an "idioplasm" transmitted inherited characteristics, dissuaded Mendel from continuing to work on plant genetics. According to Nägeli many evolutionary developments were nonadaptive and variation was internally programmed. Charles Darwin saw this as a serious challenge, replying that "There must be some efficient cause for each slight individual difference", but was unable to provide a specific answer without knowledge of genetics. Further, Darwin was himself somewhat progressionist, believing for example that "Man" was "higher" than the barnacles he studied.
Darwin indeed wrote in his 1859 Origin of Species:
File:Titanothere Osborn.jpg|thumb|upright|Henry Fairfield Osborn's 1934 version of orthogenesis, aristogenesis, argued that aristogenes, not mutation or natural selection, created all novelty. Osborn supposed that the horns of Titanotheres evolved into a baroque form, way beyond the adaptive optimum.
In 1898, after studying butterfly coloration, Theodor Eimer introduced the term orthogenesis with a widely read book, On Orthogenesis: And the Impotence of Natural Selection in Species Formation. Eimer claimed there were trends in evolution with no adaptive significance that would be difficult to explain by natural selection. To supporters of orthogenesis, in some cases species could be led by such trends to extinction. Eimer linked orthogenesis to neo-Lamarckism in his 1890 book Organic Evolution as the Result of the Inheritance of Acquired Characteristics According to the Laws of Organic Growth. He used examples such as the evolution of the horse to argue that evolution had proceeded in a regular single direction that was difficult to explain by random variation. Gould described Eimer as a materialist who rejected any vitalist or teleological approach to orthogenesis, arguing that Eimer's criticism of natural selection was common amongst many evolutionists of his generation; they were searching for alternative mechanisms, as they had come to believe that natural selection could not create new species.

Nineteenth and twentieth centuries

Numerous versions of orthogenesis have been proposed. Debate centred on whether such theories were scientific, or whether orthogenesis was inherently vitalistic or essentially theological. For example, biologists such as Maynard M. Metcalf, John Merle Coulter, David Starr Jordan and Charles B. Lipman claimed evidence for orthogenesis in bacteria, fish populations and plants. In 1950, the German paleontologist Otto Schindewolf argued that variation tends to move in a predetermined direction. He believed this was purely mechanistic, denying any kind of vitalism, but that evolution occurs due to a periodic cycle of evolutionary processes dictated by factors internal to the organism. In 1964 George Gaylord Simpson argued that orthogenetic theories such as those promulgated by Du Noüy and Sinnott were essentially theology rather than biology.
Though evolution is not progressive, it does sometimes proceed in a linear way, reinforcing characteristics in certain lineages, but such examples are entirely consistent with the modern neo-Darwinian theory of evolution. These examples have sometimes been referred to as orthoselection but are not strictly orthogenetic, and simply appear as linear and constant changes because of environmental and molecular constraints on the direction of change. The term orthoselection was first used by Ludwig Hermann Plate, and was incorporated into the modern synthesis by Julian Huxley and Bernard Rensch.
Recent work has supported the mechanism and existence of mutation biased adaptation, meaning that limited local orthogenesis is now seen as possible.

Theories

For the columns for other philosophies of evolution, "yes" means that person definitely supports the theory; "no" means explicit opposition to the theory; a blank means the matter is apparently not discussed, not part of the theory.

Author	Title	Field	Date	Lamarck.	Mutat.	Nat. Sel.	Vital.	Features
Lamarck	Inherent progressive tendency	Zoology	1809	yes				In his Philosophie Zoologique, inherent progressive tendency drives organisms continuously towards greater complexity, in separate lineages, no extinction.
Baer	Purposeful creation	Embryology	1859					"Forces which are not directed—so-called blind forces—can never produce order."
Kölliker	Heterogenesis	Anatomy	1864	yes				Wholly separate lines of descent with no common ancestor
Cope	Law of acceleration	Palaeontology	1868	yes				Combined orthogenetic constraints with Lamarckian use and disuse. "On the Origin of Genera"; See also Cope's rule
Nägeli	Inner perfecting principle	Botany	1884	yes		no		An "idioplasm" transmitted inherited characteristics; many evolutionary developments nonadaptive; variation internally programmed.
Spencer	Progressionism 'The Development Hypothesis'	Social theory	1852	Yes				Cultural value of progress; "Spencer has no rivals when it comes to open, flagrant connections of social Progress with evolutionary progress."—Michael Ruse
Darwin	, Pangenesis	Evolution	1859	yes		yes		Origin of Species is somewhat progressionist, e.g. man higher than animals, alongside natural selection Pangenesis theory of inheritance by gemmules from all over body was Lamarckian: parents could pass on traits acquired in lifetime.
Haacke	Orthogenesis	Zoology	1893	yes				Accompanied by epimorphism, a tendency to increasing perfection
Eimer	Orthogenesis	Zoology	1898			no		On Orthogenesis: And the Impotence of Natural Selection in Species Formation: trends in evolution with no adaptive significance, claimed hard to explain by natural selection.
Bergson	Elan vital	Philosophy	1907				yes	Creative Evolution
Przibram	Apogenesis	Embryology	1910s
Plate	Orthoselection or Old-Darwinism	Zoology	1913	yes	yes	yes		Combined theory
Rosa	Hologenesis	Zoology	1918	yes				Hologenesis: a New Theory of Evolution and the Geographical Distribution of Living Beings
Whitman	Orthogenesis	Zoology	1919	no	no	no		Orthogenetic Evolution in Pigeons posthumous
Berg	Nomogenesis	Zoology	1926	no	yes	no		Chemical forces direct evolution, leading to humans
Abel	Trägheitsgesetz	Palaeontology	1928					based on Dollo's law of irreversibility of evolution
Lwoff	Physiological degradation	Physiology	1930s–1940s	yes				Directed loss of functions in microorganisms
Beurlen	Orthogenesis	Palaeontology	1930	no		no		Start is random metakinesis, generating variety; then palingenesis as mechanism for orthogenesis
	Directed mutation	Protozoology, Zoology	1931	yes				Combined orthogenesis with Lamarckism
Osborn	Aristogenesis	Palaeontology	1934	yes	no	no
Willis	Differentiation	Botany	1942				yes	a force "working upon some definite law that we do not yet comprehend", compromise between special creation and natural selection, driven by large mutations involving chromosome alterations
Noüy	Telefinalism	Biophysics	1947				yes	In book Human Destiny, essentially religious
	Organicism	Zoology	1949			No		L'Homme et L'Evolution
Sinnott	Telism	Botany	1950				yes	In book Cell and Psyche, essentially religious
Schindewolf	Typostrophism	Palaeontology	1950		yes			Basic Questions in Paleontology: Geologic Time, Organic Evolution and Biological Systematics; evolution due to periodic cycle of processes dictated by factors internal to organism.
Teilhard de Chardin	Directed additivity Omega Point	Palaeontology Mysticism	1959				yes	The Phenomenon of Man posthumous; combined orthogenesis with non-material vitalist directive force aiming for a supposed "Omega Point" with creation of consciousness. Noosphere concept from Vladimir Vernadsky. Censured by Gaylord Simpson for nonscientific spiritualistic "doubletalk".
Croizat	Biological synthesis Panbiogeography	Botany	1964					mechanistic, caused by developmental constraints or phylogenetic constraints
Lima-de-Faria	Autoevolutionism	Physics, Chemistry	1988	No	No	No	No	Natural selection is immaterial so cannot work.

File:Alternatives to Darwinism.svg|thumb|upright=1.5|Multiple explanations have been offered since the 19th century for how evolution took place, given that many scientists initially had objections to natural selection. Many of these theories led to some form of orthogenesis, with or without invoking divine control directly or indirectly. For example, evolutionists like Edward Drinker Cope believed in a combination of theistic evolution, Lamarckism, vitalism, and orthogenesis, represented by a sequence of arrows on the left of the diagram. The development of modern Darwinism is indicated by dashed orange arrows.
The various alternatives to Darwinian evolution by natural selection were not necessarily mutually exclusive. The evolutionary philosophy of the American palaeontologist Edward Drinker Cope is a case in point. Cope, a religious man, began his career denying the possibility of evolution. In the 1860s, he accepted that evolution could occur, but, influenced by Agassiz, rejected natural selection. Cope accepted instead the theory of recapitulation of evolutionary history during the growth of the embryo - that ontogeny recapitulates phylogeny, which Agassiz believed showed a divine plan leading straight up to man, in a pattern revealed both in embryology and palaeontology. Cope did not go so far, seeing that evolution created a branching tree of forms, as Darwin had suggested. Each evolutionary step was however non-random: the direction was determined in advance and had a regular pattern, and steps were not adaptive but part of a divine plan. This left unanswered the question of why each step should occur, and Cope switched his theory to accommodate functional adaptation for each change. Still rejecting natural selection as the cause of adaptation, Cope turned to Lamarckism to provide the force guiding evolution. Finally, Cope supposed that Lamarckian use and disuse operated by causing a vitalist growth-force substance, "bathmism", to be concentrated in the areas of the body being most intensively used; in turn, it made these areas develop at the expense of the rest. Cope's complex set of beliefs thus assembled five evolutionary philosophies: recapitulationism, orthogenesis, theistic evolution, Lamarckism, and vitalism. Other palaeontologists and field naturalists continued to hold beliefs combining orthogenesis and Lamarckism until the modern synthesis in the 1930s.