Editing Great chain of being (section)

=== ''Scala Naturae'' in evolution ===
{{further|Orthogenesis}}

[[File:Human pedigree.jpg|thumb|upright|left|The human pedigree [[recapitulation theory|recapitulating its phylogeny]] back to [[amoeba]] shown as a reinterpreted chain of being with living and [[fossil]] animals. From a critique of [[Ernst Haeckel]]'s theories, 1873.]]

The set nature of species, and thus the absoluteness of creatures' places in the great chain, came into question during the 18th century. The dual nature of the chain, divided yet united, had always allowed for seeing creation as essentially one continuous whole, with the potential for overlap between the links.{{sfn|Lovejoy|1960|p=59}} Radical thinkers like [[Jean-Baptiste Lamarck]] saw a progression of life forms from the simplest creatures striving towards complexity and perfection, a schema accepted by zoologists like [[Henri de Blainville]].<ref>{{cite journal |last=Appel |first=T.A. |title=Henri De Blainville and the Animal Series: A Nineteenth-Century Chain of Being |journal=Journal of the History of Biology |date=1980 |volume=13 | issue = 2 |pages=291–319 |jstor=4330767 |doi=10.1007/BF00125745|s2cid=83708471 }}</ref> The very idea of an ordering of organisms, even if supposedly fixed, laid the basis for the idea of [[transmutation of species]], whether progressive goal-directed [[orthogenesis]] or [[Charles Darwin]]'s undirected theory of [[evolution]].<ref name=Snyder>{{cite web |url=http://faculty.grandview.edu/ssnyder/121/121%20great%20chain.htm |title=The Great Chain of Being |website=Grandview.edu |author=Snyder, S. |access-date=2017-01-05 |archive-url=https://web.archive.org/web/20170728101006/http://faculty.grandview.edu/ssnyder/121/121%20great%20chain.htm |archive-date=2017-07-28 |url-status=dead }}</ref>{{sfn|Lovejoy|1960|pp=325-326}}

The chain of being continued to be part of [[metaphysics]] in 19th-century education, and the concept was well known. The geologist [[Charles Lyell]] used it as a metaphor in his 1851 ''Elements of Geology'' description of the [[Geologic time scale|geological column]], where he used the term "[[Transitional fossil#Missing links|missing links]]" about missing parts of the continuum. The term "missing link" later came to signify [[transitional fossil]]s, particularly those bridging the gulf between man and beasts.<ref name="hm">{{cite web |url=http://www.hoxfulmonsters.com/2009/06/why-the-term-missing-links-is-inappropriate/ |title=Why the term "missing links" is inappropriate |date=10 June 2009 |publisher=Hoxful Monsters |access-date=10 September 2011 |url-status=dead |archive-url=https://web.archive.org/web/20120402093028/http://www.hoxfulmonsters.com/2009/06/why-the-term-missing-links-is-inappropriate/ |archive-date=2 April 2012 }}</ref>

The idea of the great chain, as well as the derived "missing link", was abandoned in early 20th-century science,<ref name=Prothero2008>{{cite journal |last=Prothero |first=Donald R. |author-link=Donald Prothero |date=1 March 2008 |title=Evolution: What missing link? |url=https://www.newscientist.com/article/mg19726451.700-evolution-what-missing-link.html?full=true |journal=[[New Scientist]] |issue=2645 |pages=35–41 |access-date=4 August 2018 |doi=10.1016/s0262-4079(08)60548-5 |volume=197 |archive-date=23 May 2020 |archive-url=https://web.archive.org/web/20200523045311/https://www.newscientist.com/article/mg19726451-700-evolution-what-missing-link/?ignored=irrelevant |url-status=live }}</ref> as the notion of [[Ontogeny recapitulates phylogeny|modern animals representing ancestors of other modern animals]] was abandoned in biology, to be replaced by an [[Phylogenetic tree|evolutionary tree]] supplemented by [[horizontal gene transfer]], as well as more complex [[Food web|web structures]].<ref name=Ehrlich1963>{{cite book | last1=Ehrlich | first1=Paul R. |author2=Holm, R. W. |author1-link=Paul R. Ehrlich | title=The process of evolution | url=https://archive.org/details/processofevoluti00ehrl | publisher=McGraw-Hill | location=New York | year=1963 | isbn=978-0-07-019130-3 | oclc=255345 | page=[https://archive.org/details/processofevoluti00ehrl/page/66 66]}}</ref> The idea of a certain sequence from lower to higher complexity and fitness is still popular, as is the idea of [[orthogenesis|progress in biology]].<ref>{{cite book |last=Ruse |first=Michael |author-link=Michael Ruse |date=1996 |title=Monad to man: the Concept of Progress in Evolutionary Biology |url=https://archive.org/details/monadtomanconcep0000ruse |url-access=registration |publisher=Harvard University Press |isbn=978-0-674-03248-4 |pages=[https://archive.org/details/monadtomanconcep0000ruse/page/432 432]–433, and passim}}</ref>{{clear|left}}