Similar patterns of frequency‐dependent selection on animal personalities emerge in three species of social spiders

Abstract

Frequency-dependent selection is thought to be a major contributor to the maintenance of phenotypic variation. We tested for frequency-dependent selection on contrasting behavioural strategies, termed here 'personalities', in three species of social spiders, each thought to represent an independent evolutionary origin of sociality. The evolution of sociality in the spider genus Anelosimus is consistently met with the emergence of two temporally stable discrete personality types: an 'aggressive' or 'docile' form. We assessed how the foraging success of each phenotype changes as a function of its representation within a colony. We did this by creating experimental colonies of various compositions (six aggressives, three aggressives and three dociles, one aggressive and five dociles, six dociles), maintaining them in a common garden for 3 weeks, and tracking the mass gained by individuals of either phenotype. We found that both the docile and aggressive phenotypes experienced their greatest mass gain in mixed colonies of mostly docile individuals. However, the performance of both phenotypes decreased as the frequency of the aggressive phenotype increased. Nearly identical patterns of phenotype-specific frequency dependence were recovered in all three species. Naturally occurring colonies of these spiders exhibit mixtures dominated by the docile phenotype, suggesting that these spiders may have evolved mechanisms to maintain the compositions that maximize the success of the colony without compromising the expected reproductive output of either phenotype.

Participation in cooperative prey capture and the benefits gained from it are associated with individual personality

“…Colonies without any bold individuals tended to lose weight and colonies containing just 1 bold individual gained significant amounts of mass (Figure 2). These findings support considerable existing literature suggesting that personality diversity increases group performance (Pinter-Wollman 2012b) in ants (Modlmeier and Foitzik 2011; Modlmeier et al 2012) and other social spider species (Lichtenstein and Pruitt 2015). At the same time, they contradict evidence demonstrating that behavioral diversity does not increase group performance (Jandt and Dornhaus 2014).…”

“…At the same time, existing theoretical (Biro and Stamps 2008; Careau et al 2008, Stamps 2007) and empirical evidence (Kühbandner et al 2014; Shearer and Pruitt 2014) indicates that bold individuals have higher metabolic rates than shy individuals. Specifically, bold individuals are less resistant to starvation (Lichtenstein and Pruitt 2015) and exhibit higher heart rates during stressful encounters (Shearer and Pruitt 2014). These findings in tandem with the well-studied link between boldness, activity level, and foraging success (Werner and Anholt 1993; Short and Petren 2008; Smith and Blumstein 2008) hint that bolder individuals might need to consume more food to maintain their active foraging strategies (Stamps 2007; Biro and Stamps 2008).…”

Emergent adaptive behaviour of GRN-controlled simulated robots in a changing environment

“…As a matter of fact, such nested architecture involving different levels of organization can be observed in all biological systems and makes the evolutionary process tick at multiple levels in parallel (Poli, 2001; Mazzocchi, 2010; Wilson, Vugt & O’Gorman, 2008; Koch, 2012). Natural selection and subsequent adaptation is highly dependent on the current environmental and evolutionary context (Allison, 1956; Harper & Pfennig, 2007; Bijma, Muir & Arendonk, 2007; Lichtenstein & Pruitt, 2015). Furthermore, adaptation to a complex environment or to a complex change in environment requires time for interactions between individual entities to evolve gradually.…”

Early Environmental Conditions Shape Personality Types in a Jumping Spider

“…As for developmental behavioral plasticity in general, the potential for these plastic responses might be restricted to sensitive periods during ontogenesis (e.g., Groothuis and Trillmich, 2011;or "developmental windows": Luttbeg and Sih, 2010;Faulk and Dolinoy, 2011), since changing an once adopted behavioral phenotype is associated with cost (reviewed in Snell-Rood, 2013). These processes can therefore lead to consistently different phenotypes even with similar genotypes (see Sih et al, 2004;Luttbeg and Sih, 2010) and these differences may be under frequency dependent selection (Lichtenstein and Pruitt, 2015).…”