Evolution of Development

At the end of the nineteenth and beginning of the twentieth century, the fields of evolutionary and developmental biology were inseparable. Evolutionary biologists used comparative embryology to reconstruct ancestors and phyletic relationships, and embryologists in turn used evolutionary history to explain many of the processes observed during animal development. This close relationship ended after the rise of experimental embryology and Mendelian genetics at the beginning of the twentieth century. Now, after almost 100 years of separation, these two fields have reunited to form a distinct discipline called ‘evolutionary developmental biology’, whose aim is to understand the relationship between evolution of genotype and evolution of phenotype, as well as how developmental genes and processes evolve.