Climate and body size have differential roles on melanism evolution across workers in a worldwide ant genus

Abstract One of the main aspects associated with the diversity in animal colour is the variation in melanization levels. In ectotherms, melanism can be advantageous in aiding thermoregulation through heat absorption. Darker bodies may also serve as a shield from harmful UV-B radiation. Melanism may also confer protection against parasites and predators through improving immunity responses and camouflage in regions with high precipitation, with complex and shaded vegetations and greater diversity of pathogens and parasites. We studied melanism evolution in the globally distributed ant genus Pheidole under the pressures of temperature, UV-B radiation and precipitation, while considering the effects of body size and nest habit, traits that are commonly overlooked. More importantly, we account for worker caste polymorphism, which is marked by distinct roles and behaviours. We revealed for the first time distinct evolutionary trajectories for each worker subcaste. As expected, major workers from species inhabiting locations with lower temperatures and higher precipitation tend to be more melanised. Curiously, we show a slight trend where minor workers of larger species also tend to have darker bodies when inhabiting regions with higher precipitation. Lastly, we did not find evidence for the effects of UV-B radiation and nest habit in the lightness variation of workers. Our paper explores the evolution of ant melanization considering a marked ant worker polymorphism and a wide range of ecological factors. We discuss our findings under the light of the Thermal Melanism Hypothesis, the Photoprotection Hypothesis and the Gloger’s Rule..

Medienart:

Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:199

Enthalten in:

Oecologia - 199(2022), 3 vom: Juli, Seite 579-587

Sprache:

Englisch

Beteiligte Personen:

Klunk, Cristian L. [VerfasserIn]
Fratoni, Rafael O. [VerfasserIn]
Rivadeneira, C. Daniel [VerfasserIn]
Schaedler, Laura M. [VerfasserIn]
Perez, Daniela M. [VerfasserIn]

Links:

Volltext [lizenzpflichtig]

Themen:

Gloger’s rule
Photoprotection
Temperature
Thermal melanism
Worker polymorphism

Anmerkungen:

© The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2022

doi:

10.1007/s00442-022-05211-x

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

OLC207921361X