Editing Evolutionary developmental biology (section)

===Recapitulation===
{{Main|Recapitulation theory}}

[[File:Haeckel vs von Baer.svg|thumb|upright=1.5|Embryology theories of [[Ernst Haeckel]], who argued for [[recapitulation theory|recapitulation]]<ref>{{harvnb|Richardson|Keuck|2002|p=516}}</ref> of evolutionary development in the embryo, and [[Karl Ernst von Baer]]'s [[epigenesis (biology)|epigenesis]] ]]

A [[recapitulation theory]] of evolutionary development was proposed by [[Étienne Serres]] in 1824–26, echoing the 1808 ideas of [[Johann Friedrich Meckel]]. They argued that the embryos of 'higher' animals went through or recapitulated a series of stages, each of which resembled an animal lower down the [[great chain of being]]. For example, the brain of a human embryo looked first like that of a [[fish]], then in turn like that of a [[reptile]], [[bird]], and [[mammal]] before becoming clearly [[human]]. The embryologist [[Karl Ernst von Baer]] opposed this, arguing in 1828 that there was no linear sequence as in the great chain of being, based on a single [[body plan]], but a process of [[epigenesis (biology)|epigenesis]] in which structures differentiate. Von Baer instead recognized four distinct animal [[body plan]]s: radiate, like [[starfish]]; molluscan, like [[clam]]s; articulate, like [[lobster]]s; and vertebrate, like fish. Zoologists then largely abandoned recapitulation, though [[Ernst Haeckel]] revived it in 1866.<ref>{{Cite web |last=O'Connell |first=Lindsey |date=10 July 2013 |title=The Meckel-Serres Conception of Recapitulation |url=https://embryo.asu.edu/pages/meckel-serres-conception-recapitulation |access-date=10 October 2016 |website=The Embryo Project Encyclopedia}}</ref><ref>{{Cite book |last=Desmond |first=Adrian J. |author-link=Adrian Desmond |url=https://archive.org/details/politicsofevolut00adri/page/53 |title=The politics of evolution: morphology, medicine, and reform in radical London |publisher=University of Chicago Press |year=1989 |isbn=978-0-226-14374-3 |location=Chicago |pages=[https://archive.org/details/politicsofevolut00adri/page/53 53–53, 86–88, 337–340, 490–491] |url-access=registration}}</ref><ref>{{harvnb|Secord|2003|pp=252–253}}</ref><ref>{{Cite book |last=Bowler |first=Peter J. |url=https://archive.org/details/evolutionhistory0000bowl_n7y8/page/120 |title=Evolution: the history of an idea |publisher=University of California Press |year=2003 |isbn=978-0-520-23693-6 |location=Berkeley |pages=[https://archive.org/details/evolutionhistory0000bowl_n7y8/page/120 120–128, 190–191, 208]}}</ref><ref>{{harvnb|Secord|2003|pp=424, 512}}</ref>

{{anchor|Heterotopy}}<!--until an article on this appears-->