Molecular techniques have revolutionized the ability of biologists to discover the paths of evolution that have lead to the vast diversity of life that exists on earth. The Phylum Arthropoda, including insects, spiders and crustaceans, is the most diverse of all the animal groups, accounting for more than 80% of animal biomass on earth, however some of the evolutionary relationships among these chitinous critters are still unknown. MSC graduate student Stefan Kaluziak demonstrates the power of molecular tools in determining Arthropod phylogenetic relationships in his recently co-authored publication in the journal Molecular Biology and Evolution.

In order to shed light on understudied phylogenetic relationships among members of the class Arachnida, which includes spiders and scorpions, Kaluziak and colleagues collected DNA from 17 Arachnid species. After determining the unique DNA sequence of each sample, they used a variety of methods to organize the species into a phylogenetic tree based on similarities and differences in the DNA sequences.

Results indicate that some of the generally accepted relationships among Arachnids, including the theory that the group originated from a common ancestor, may be untrue. This work highlights the importance of molecular methods to inform evolutionary biology and phylogenetic research, allowing scientists to look into the past to demystify the complex relationships among all organisms in the evolutionary tree of life.