Cephalotes is a genus of tree-dwelling ant species from the Americas, commonly known as turtle ants. All appear to be gliding ants, with the ability to "parachute" and steer their fall so as to land back on the tree trunk rather than fall to the ground, which is often flooded.[2][3]
One of the most important aspects of the genus' social evolution and adaptation is the manner in which their social organization has been shaped by environmental pressures.[4] This is particularly true of the species Cephalotes rohweri, in which an entire soldier class has evolved as a result of highly specialized nest cavity availability.[5]
Because ants within Cephalotes use multiple carved nesting cavities found in the trees upon which they live, a cohort of morphologically specialized soldiers has evolved to defend these nesting cavities. They use their unique plate-like heads to block the entrances to the nests, essentially creating a living door to the nest cavities.[5]
In one particular study, Scott Powell tested the hypothesis that "specialized use of cavities with entrances close to the area of one ant head has selected for a morphologically and behaviorally specialized soldier in Cephalotes." This was accomplished by performing comparative studies between four Cephalotes species, each representing one of the four character states of soldier evolution.[5] Cephalotes was ideal for the study because it is the only genus to contain extant species displaying four levels of major morphological evolution.[5] These character states are:
Another study by Powell examined the process by which environmental factors shape colonial castes within the worker class. However, this study focused more on how colonies adapt their caste systems to ecological factors in their environment.[6]
For the experiment, a species of the genus Cephalotes was used that displayed the highest level of soldier specialization. Three key findings regarding adaptive caste specialization were supported: