Continuous peristaltic waves commenced sequentially at the distal end and moved down the body until they were lost from sight in the snail tissue.
First, participants were required to name all of the pictured stimuli in a lesson before instruction commenced.
Birth intervals have been calculated for all births in the survey areas that commenced and ended with a known date of birth.
All infections commenced with a single gravid worm attached to the central region of the caudal fin.
The experiment was commenced by opening a valve to allow the coolant to pass through the brass plate.
When emerged males were present, the courtship process commenced immediately upon the protrusion of the female's head from the emergence hole.
There is evidence that this process may have commenced prior to the last common ancestor, but if so, it was still in its infancy.
The stages may overlap, in that further evolution of one stage may continue to complexify after evolution of a later stage has commenced.
