Editing Modern synthesis (20th century) (section)

===Lewis's homeotic genes, 1978===

[[File:Genes hox.jpeg|thumb|upright=1.<!--format to make text labels legible-->75|[[Evolutionary developmental biology]] has formed a synthesis of evolutionary and [[developmental biology]], discovering [[deep homology]] between the [[embryogenesis]] of such different animals as [[insect]]s and [[vertebrate]]s.]]

{{main|Evolutionary developmental biology}}

In 1977, [[recombinant DNA]] technology enabled biologists to start to explore the genetic control of development. The growth of [[evolutionary developmental biology]] from 1978, when [[Edward B. Lewis]] discovered [[homeotic]] genes, showed that many so-called [[toolkit gene]]s act to regulate development, influencing the expression of other genes. It also revealed that some of the regulatory genes are extremely ancient, so that animals as different as insects and mammals share control mechanisms; for example, the ''[[Pax6]]'' gene is involved in forming the [[eye]]s of mice and of fruit flies. Such [[deep homology]] provided strong evidence for evolution and indicated the paths that evolution had taken.<ref name=Gilbert2000>{{cite book |last=Gilbert |first=Scott F. |author-link=Scott F. Gilbert |chapter=A New Evolutionary Synthesis |title=Developmental Biology |date=2000 |publisher=[[Sinauer Associates]] |url=https://www.ncbi.nlm.nih.gov/books/NBK10128/}}</ref>