Mike Lee and colleagues from the University of Adelaide in Australia presented new evidence that explains why the rates of genetic evolution and anatomical evolution were so fast during the Cambrian explosion and that these events are compatible with Darwinian evolutionary theory in the Sept. 12, 2013, edition of the journal Current Biology.
The huge variety of arthropod life that developed during the Cambrian period between 540 and 520 million years ago has been viewed as being at odds with Darwinian evolution. Arthropods are insects, spiders, crustaceans and their predecessors.
The researchers examined the genetic and anatomical differences between arthropods living at present to develop a concept of how so much evolutionary diversity could have been possible in the relative short period of 20 million years. Evolution is assumed to be a slow process.
The scientists found that rates of evolution in arthropods during the Cambrian explosion were four to five times as fast as any other time in history. The convergence of active swimming, new forms of vision, new methods of predation, and other adaptations served to speed up the evolutionary process for a short period of time.
Arthropods make up the largest number of species in modern times and this fact also evinces the rapid evolution of arthropods during the Cambrian period.