The discovery of HOX genes in1983depended on the use of
1. radioactive isotopes; allowed scientists to turn on and off certain genes.
2. The use of antibody stains to see the gene in action. Bands in the embryo.
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These are new technologies that reveal evidencesupporting the theory of evolution.
(In contrast, fossil evidence, homologous structures, Wallace’s line etc are traditional or old forms of evidence.). Therefore they cannot be used in this answer.
Gene switches such as HOX MAKE THE make the initial decisions of which genes to turn on or off in different body regions and cell types
The fact that so many species rely on the same genes to control the development of the embryo implies a link to a common ancestor. Early on in the evolution of life on Earth, these genes developed and were successful. They thus remained in the genome of all multicellular organisms.
The greater the number of similarities in the HOX genes of two species, the more closely they are related.
HOX genes