A fascinating discovery concerning termites has illuminated a notable repercussion of sustained monogamy: the diminished rivalry among the spermatozoa of competing males consequently led to the forfeiture of their tails.
This phenomenon entailed the regression of a suite of genes integral to their remarkable metamorphosis from solitary cockroaches to exceptionally gregarious termites, according to a recent investigation. In essence, the abdication of sperm mobility represented the evolutionary cost incurred by these insects for the establishment of their highly inbred communal structures.
“This research underscores that comprehending social evolution transcends merely acquiring novel characteristics,” asserts Nathan Lo, an evolutionary biologist at the University of Sydney and a co-author of the study. “At times, it hinges upon what evolutionary processes elect to relinquish.”
“Our findings suggest that the progenitors of termites were exclusively monogamous. Once this monogamous reproductive strategy was firmly established, any evolutionary impetus for preserving genes associated with sperm motility ceased to exist.”
The genetic makeup, developmental physiology, and behavioral patterns of these obligatorily social creatures indicate that dietary specialization played a pivotal role in their transition to a communal existence.
“Termites originated from cockroach ancestors who began inhabiting and subsisting on wood,” elucidates Lo. “Our research elucidates the sequence of genetic alterations that occurred as they adapted to this nutrient-poor sustenance and subsequently evolved into social organisms.”
In a comparative analysis of cockroaches and termites, Yingying Cui, an entomologist at South China Normal University, alongside Lo and their colleagues, observed that termites possess considerably more limited genetic repertoires than cockroaches, with a reduced complement of genes associated with metabolism, digestion, and reproduction.
“The unexpected revelation is that termites augmented their social complexity through a reduction in genetic complexity,” comments Lo. “This contradicts the prevalent assumption that more intricate animal societies necessitate more elaborate genomes.”
Furthermore, the temporal regulation of energy metabolism gene expression, influenced by the quantity of sustenance provided by older colony members, dictated whether a termite larva would develop into a worker or a prospective king or queen of the colony.
Abundant food availability facilitates accelerated development into workers; a scarcity of nourishment promotes slower maturation into a reproductive nymph. Should these nymphs ultimately ascend to reproductive roles, they engage in procreation with their kin.
“These reciprocal food-sharing mechanisms enable colonies to precisely calibrate their labor force,” explains Lo. “They contribute to our understanding of how termites sustain stable, highly efficacious societies over extended durations.”
Collectively, these findings indicate that, at least within the termite lineage, monogamy and a high degree of relatedness were indispensable for the emergence of their sophisticated social organization. This is certainly not a paradigm that mammals are advised to emulate, despite the occasional attempts observed.
