So much of talk is going around about Hox genes in the field of evolution and some might wonder what makes them so important in this field as well, along with developmental biology. What is that we are going to learn about evolution by studying Hox proteins? or to put it in another way : Why Hox genes are pivotal for evo devo???
Hox genes or Homeotic genes were first discovered in Fruit fly Drosophila and later homologous genes were found in all metazoans except sponges and Ctenophores. This was possible only after the discovery of Homeobox motif which forms the heart of Hox genes. They play a similar function in most of the animals of patterning the anterior posterior axis in early development.Despite a huge diversity in body plan (which reflects their mode of development) observed in various organisms on planet ,they still have commonality when it comes to Hox genes. All organisms share Hox gene clusters, characterized by a high degree of sequence conservation and a colinear gene arrangement which could be understood only on basis of evolution.
In the era of genomics Hox genes are well suited for reconstruction of ancestral genomes as they are conserved through out evolution and robust family level phylogeny. In this way Hox genes have paved the path for new field of evolutionary developmental biology or evo devo.