The study even controlled for age, the emotional expression in the photos and the physical attractiveness of the individuals by obtaining separate ratings of these from other students and using statistical techniques to remove their effects.
Caves were thought to be essentially devoid of life until six years ago, when the renowned University of Colorado microbiologist Norman Pace, also an avid caver, discovered a way to identify extremophile microorganisms by cloning and sequencing unique sections of their DNA. Prior to Pace's work biologists had fruitlessly tried to cultivate these microorganisms with traditional lab techniquesusing nutrient-rich petri dishes.