Brains, Innovations and Evolution in Birds and Primates

Abstract

Several comparative research programs have focused on the cognitive, life history and ecological traits that account for variation in brain size. We review one of these programs, a program that uses the reported frequency of behavioral innovation as an operational measure of cognition. In both birds and primates, innovation rate is positively correlated with the relative size of association areas in the brain, the hyperstriatum ventrale and neostriatum in birds and the isocortex and striatum in primates. Innovation rate is also positively correlated with the taxonomic distribution of tool use, as well as interspecific differences in learning. Some features of cognition have thus evolved in a remarkably similar way in primates and at least six phyletically-independent avian lineages. In birds, innovation rate is associated with the ability of species to deal with seasonal changes in the environment and to establish themselves in new regions, and it also appears to be related to the rate at which lineages diversify. Innovation rate provides a useful tool to quantify inter-taxon differences in cognition and to test classic hypotheses regarding the evolution of the brain.

Mice selectively bred for high voluntary wheel running have larger midbrains: support for the mosaic model of brain evolution

“…A number of hypotheses have been generated to explain how selection may have driven changes in brain size (Francis, 1995;Barton and Harvey, 2000; de Winter and Oxnard, 2001;Hutcheon et al, 2002; Byrne and Corp, 2004;Lefebvre et al, 2004;Marino, 2005;Sol et al, 2005;Lefebvre and Sol, 2008;Rehkämper et al, 2008;Sol et al, 2008; Chittka and Niven, 2009;Roth and Pravosudov, 2009). Most, if not all, of these hypotheses suggest that selection is acting on behavior [e.g.…”

If at first you don't succeed… Studies of ontogeny shed light on the cognitive demands of habitual tool use

“…An ability to innovate, knowledge of object properties and observational learning has been suggested to be important [67]. All of these have been shown to correlate with slow life histories and brain encephalization [68][69][70][71]. In this section, we examine evidence from captive studies on problem solving with objects and tools, and consider how studying cognitive underpinnings and developmental change might help us to identify candidate cognitive adaptations underpinning habitual adult tool use.…”

Mapping behavioural evolution onto brain evolution: the strategic roles of conserved organization in individuals and species

“…Pervasive increases in relative brain size with respect to body size ('encephalization') in multiple lineages over evolutionary time and its association with behavioural complexity (without any direct measure of fitness) were first described systematically by Jerison [2]. More recently, the same simple feature of relative brain size (at the species level) has been shown to have direct links to fitness, in innovative studies of multiple species of both birds and mammals in natural ecology [32]. These fitness indicators include annual mortality rate, probability of an individual species' survival when introduced into a new niche, and behavioural innovation in diet.…”