Stephen Smith just wanted to study honeysuckle. As a new PhD student at Yale University in 2003, “I was going to do a strict monograph,” says Smith. But when he sat down to research the evolution of the genus, he learned that the honeysuckle fossil record is poor, so Smith decided to temporarily expand his research to include the fossils of related plants.
Smith decided to build an evolutionary tree, or phylogeny, of all the Dipsacales, a major group of flowering plants that includes honeysuckles. His advisor, Yale botanist Michael Donoghue, was skeptical. It was a project that he, a world expert on Dipsacales, had attempted but eventually abandoned: There are over 1,000 species of Dipsacales, and at the time, most plant phylogenies maxed out at about 200 organisms due to the complexity of comparing genetic sequences.
Genetic Evidence for Punctuated Equilibrium
But within a ...
