The evolution of behavioural systems: a study of grooming in rodents

Abstract

In the present paper we focus on the study of complex behavioural systems, within an explicit phylogenetic framework. We reconstruct the phylogeny of rodents using grooming sequences from 12 terminals. Using a method derived from graph theory, we decompose complex behavioural systems into strings of behavioural units (behavioural routines) which are then used as behavioural characters to compose the phylogenetic matrix in addition to three mitochondrial markers as molecular characters (the cytochrome b gene (cytb), the 16S ribosomal RNA gene and the 12S ribosomal RNA gene). Our results point to a highly structured behavioural morphospace: only a few characters have been selected for, within the total space of possibilities. The optimization of hundreds of non-homoplastic routines onto three distinct phylogenies (behavioural, combined data and the molecular supertree of Fabre et al., 2012) reveals the same evolutionary trend from simple to complex: while simple behavioural routines (zero- or first-order sequences) are synapomorphies at basal levels of the phylogeny, progressively more complex behaviours evolve later, appearing closer to the tips of the phylogeny. Also, the optimization shows that the organisation of units into modules of coordinated action patterns first evolved around large body parts, namely the head and the trunk, modules that were later fused into one single organising module among rodents. We support the use of complex behavioural systems as a promising tool in the study of evolutionary scenarios and discuss the role of routines length and microstructure to provide phylogenetic information and elucidate evolutionary processes.

Species associations and trait dissimilarity in communities of ectoparasitic arthropods harboured by small mammals at three hierarchical scales

“…In particular, host defences include anti-parasitic grooming and immune responses. In small mammals, grooming ability is a species-specific trait associated with body size, as well as the physical anatomy of paws, limbs, neck, and body trunk, and, to some extent, has a phylogenetic basis (Nikitina & Nikolaeva, 1979;Berridge, 1990;Malange et al, 2013). Regarding immune responses, it has been shown that immunocompetence in small mammals is also, to some extent, a species-specific trait (Goüy de Bellocq et al, 2006), although it may vary among individuals within a host population depending on age, sex, and nutritional and/or reproductive status (Lochmiller et al, 1993;Nelson & Demas, 1996;Humphreys & Grencis, 2002).…”

Comparing hair-morphology and molecular methods to identify fecal samples from Neotropical felids

“…Felids are strictly carnivorous and their feces contain large amounts of prey hairs and/or feathers. Furthermore, felids display a characteristic, copious grooming behavior [ 38 , 39 ]. In the process of grooming, shed hairs are swallowed and later appear in the feces.…”

Behaviour of cranes (family Gruidae) mirrors their phylogenetic relationships

“…Our findings correspond with other works according to which behavioural data carry strong phylogenetic signal and are no more homoplasious than other data sets. For example, as shown in the meta-analysis of de Queiroz and Wimberger (1993), studies of evolution on bovid behaviour (Deleporte and Cap 2014), behaviour and vocalization in deer (Cap et al 2002(Cap et al , 2008, grooming behaviour in rodents (Malange et al 2013) or social displays of the Pelecaniformes (Kennedy et al 1996), as well as of courtship behaviour in salamanders (Arnold et al 2017) and in seabird behaviour (Paterson et al 1995).…”