For nearly a century, biologists relied on fossil records and morphological comparisons to reveal the evolutionary histories of organisms. But most phylogenetic trees need more than phenotypic evidence to weather the intense debate in which reconstructionists are known to engage. With the advent of molecular phylogenetics in the 1960s came the hope of better trees, but it took nearly 40 years for them to materialize. With sequencing and analysis tools, modern phylogeneticists are finally building trees that can withstand scientific scrutiny.
This issue's first two Hot Papers demonstrate DNA's ability to reveal novel branching patterns in mammalian evolution.1,2 A third discusses using DNA sequence changes across evolutionary history to extrapolate function and even study genomic evolution.3 Researchers working to build definitive trees are finding their hopes fulfilled, and then some (see 5-Prime p. 14).
With the largest DNA sequencing database ever used to determine placental- mammal evolution, scientists from Stephen ...
