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]
Ecological specialization and evolution of a soldier caste
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] Because ants within Cephalotes use nesting cavities found in the trees upon which they live, most species have evolved a cohort of morphologically specialized soldiers, which defend these nesting cavities[5]. They use their distinctive plate-like heads to block the entrances to the nests, essentially creating a living door to the nest cavities.[5]
The relationship between soldier head morphology and nest defense has been investigated[5]. Whereas species with less-specialized soldiers engage in both active and passive (blocking) behaviors to defend nests, species with more-specialized soldiers engage in only passive, blocking defense behavior[5].
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:
Soldiers were best at defending the specific nesting resource found in nature.
Colonies used only certain nests (out of all the available nests), and selected only the nesting sites that would maximize soldier performance.
Soldier performance and limitations had both direct and indirect effects on colony reproduction.[6]
The results of this experiment support the concept that the most specialized soldier phenotype in Cephalotes is a result of adaptation to ecological specialization within a narrow subset of available nests.[6]
The fossil record is restricted to the Miocene with species recovered from both Dominican and Mexican ambers. Species were initially described by Gijsbertus Vierbergen and Joachim Scheven (1995) whole placed the species into the genera Cephalotes, Eucryptocerus, Exocryptocerus and Zacryptocerus. All four genera were revised four years later by Maria De Andrade and Cesare Baroni Urbani (1999, who synonymized them under Cephalotes.[8]
The Dominican amber species:
↑Hölldobler, B., Wilson, E. O., & Nelson, M. C. (2009). The superorganism: the beauty, elegance, and strangeness of insect societies. New York: W.W. Norton.
1234Powell, S. (2008). Ecological specialization and the evolution of a specialized caste in Cephalotes ant. Functional Ecology, 22, 902-911.
123Powell, S. (2009). How ecology shapes caste evolution: linking resource use, morphology, performance and fitness in a superorganism. Evolutionary Biology, 22, 1004-1013.
1234de Andrade, M. L.; Baroni Urbani, C. (1999). "Diversity and adaptation in the ant genus Cephalotes, past and present". Stuttgarter Beiträge zur Naturkunde, Serie B (Geologie und Paläontologie). 271: 537–538.
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