Editing Embryology (section)

== Evolutionary embryology ==
{{further|Evolutionary developmental biology}}

Evolutionary embryology is the expansion of comparative embryology by the ideas of [[Charles Darwin]]. Similarly to [[Karl Ernst von Baer]]'s principles that explained why many species often appear similar to one another in early developmental stages, Darwin argued that the relationship between groups can be determined based upon common embryonic and larval structures.

=== Von Baer's principles ===

# The general features appear earlier in development than do the specialized features.
# More specialized characters develop from the more general ones.
# The embryo of a given species never resembles the adult form of a lower one.
# The embryo of a given species does resemble the embryonic form of a lower one.<ref name=":0">{{Cite book|last1=Gilbert |first1=Scott F. |title=Developmental biology|last2=Barresi |first2=Michael J. F. |date=15 June 2016|isbn=978-1-60535-470-5|edition=Eleventh|location=Sunderland, Massachusetts|oclc=945169933}}</ref>

Using Darwin's theory evolutionary embryologists have since been able to distinguish between homologous and analogous structures between varying species. [[Homologous structure]]s are those that the similarities between them are derived from a common ancestor, such as the human arm and bat wings. [[Analogous Structure|Analogous structures]] are those that appear to be similar but have no common ancestral derivation.<ref name=":0" />