“Speciation has been notoriously difficult to thoroughly investigate because it happens too slowly to directly observe,” said Justin Meyer, a professor of biology at UC San Diego and a participant in the experiment. “Without direct evidence for speciation, some people have doubted the importance of evolution and Darwin’s theory of natural selection.”

In the experiment, the team used a virus known as “bacteriophage lambda,” which infects strains of the bacteria E. coli by attaching to receptors on the exterior of the bacterial cell wall and then infecting the cell itself. When the team introduced to the viral culture new bacteria that had two different types of receptors, it was observed that the virus specialized into two species, each having a different receptor type.

“The specialized viruses were much better at infecting through their preferred receptor and blocked their ‘jack of all trades’ ancestor from infecting cells and reproducing,” Meyer said. “The survival of the fittest led to the emergence of two new specialized viruses.”

What is remarkable from this development is the amazing ability to observe, in a laboratory setting, something as elusive and seemingly distant as speciation. This development not only provides evidence in favor of evolutionary principles, but also simultaneously denies legitimacy of theories on the contrary. Of course, what remains to be seen is the replication of this experiment for its verification, but its principal findings are consistent with the accepted bodies of knowledge. Essentially, arguments reliant upon evidence are, to our knowledge, the strongest there are. Contrary to what certain groups may claim, evidence is not derived from authority, and it is not subject to agreeability. Hopefully, this instance can serve as an example of the importance of scientific evidence and the central role it plays in the advancement and promotion of knowledge.

Which sentence in the passage above best explains the importance of empirical data for developing scientific explanations? Based on information from this lesson and your prior knowledge, justify your choice.