Catalyzing Transitions to Sociality: Ecology Builds on Parental Care

Abstract

In the context of social evolution research, great emphasis on kin-selected benefits has led to an understanding of parental care as one of the activities that helpers can perform in extended cooperative families. Nevertheless, this perspective might have precluded a deeper understanding of the implications of parental care for social evolution. We argue that parental care is a broader set of processes playing a key role both before and during the emergence of sociality. The care system of a species may be understood as the result of long coevolutionary processes with environmental pressures during presocial stages that impact transitions to sociality. We evaluate the present framework against evidence on the evolution of parental care and transitions toward sociality in subsocial and parasocial vertebrate and invertebrate species. Moreover, following previous evidence for the importance of modes of foraging and resting, we structure our inquiry by classifying societies into three types. Our results suggest that in "central place foragers" and "fortress defenders", ecological factors promoting the evolution of parental care foster a set of coevolutionary feedback loops resulting in increases in parental effort and offspring needs. Offspring needs alone or in combination with limited breeding options enhance the relative benefits of positive social interactions, catalyzing transitions to sociality. In "itinerant foragers", sociality is associated with colonizing new niches. Changes in predation pressure entail changes in the modes of care or selection for certain types of care already present in solitary ancestors. Further changes in the form of collective defense may be needed for permanent sociality to evolve. We conclude that there is evidence that social transitions to different types of societies are the result of long coevolutionary processes between environmental pressures and the care systems in a wide variety of taxa. Therefore, advances in the study of the origins of sociality may require further investigation of parental care evolution in solitary ancestors of today's social species.

The impact of kinship composition on social structure

“…Dyads of individuals that belonged to the same simulated kin cluster were considered kin and dyads that belonged to different kin clusters were considered non-kin. More generally, this kinship structure is likely common to other mix-related societies as the grouping of unrelated individuals is a possible way that groups arise (Socias-Martínez and Kappeler 2019), which might result in groups featuring independent family lines. We simulated the kin biases observed in Cayo Santiago by parameterising the two agent-based models with the empirical mean probability that kin dyads and non-kin dyads had a social relationship and with the empirical mean strength and SD of those relationships (see Results).…”

The weird eusociality of polyembryonic parasites

“…Why are overlapping generations important for the evolution of eusocial groups? While convincing arguments have been made for why we can ignore this trait in our terminological categories [25], parent-offspring grouping plays a fundamental role in the evolution of social behaviours via kin selection [51], and is incorporated into many theoretical frameworks of social evolution [52][53][54][55][56]. However, family living is not intrinsically important.…”

Co-option of ancestral signal elements in the evolution of a cooperative parental behavior

“…While traditionally examined through the lens of group size (3–5), there is increasing interest in understanding how these co-evolutionary dynamics play out across multiple indices of social complexity (6–8). Parental care is a major component of a species’ social system (9) and represents a key step in the evolution of complex sociality (10). When care responsibilities are shared between multiple caregivers, ensuring offspring survival requires coordinated behaviors that rely on effective communication.…”