Development: clinical and evolutionary considerations

The Linnean tercentenary is a most welcome opportunity to celebrate the complimentary contributions of the molecular taxonomists and the morphologists in establishing a "natural order" of living organisms depending on degree of relatedness and the 70th anniversary of birth of our friend and colleague, M. Michael Cohen Jr. These events lead one to reflect on the relationship between evolution and normal, respectively abnormal development. In part due to Mike Cohen's efforts, such reflections will at last also creep into the clinic given that more and more malformations are understood ontogenetically and phylogenetically on the basis of homology in structure, development and genetic basis in more or less closely related organisms. It is inconceivable how such an understanding can allow anyone to deny the reality of evolution and its implications for the antiquity of the earth, and its biosphere and the vulnerability of all species, humans included, for extinction.