Human origins and the evolution of social complexity

I believe the time is ripe for major advances in our understanding of human origins and subsequent social evolution. I have worked on the evolution of human brain size and intelligence  formalizing the hypothesis of Machiavellian (or social) intelligence (Gavrilets&Vose 2006), on models of the dynamics of coalition and alliance formation  (Gavrilets et al 2008; Mesterton-Gibbons et al 2011, Gavrilets 2012b), on the transition from promiscuity to pair-bonding in our lineage (Gavrilets 2012a), on the evolutionary origins of human egalitarian syndrome (Gavrilets 2012b), and the evolution of social instincts in between-group conflicts (Gavrilets and Fortunato 2014). I have a number of related ongoing projects.

With Peter Turchin, Tom Currie, and others we are building a new science of cliodynamics - a transdisciplinary research program integrating historical macrosociology, economic history/cliometrics, mathematical modeling of long-term social processes, and the construction and analysis of historical databases. Check out our recent papers on a mathematical theory of the origin of chiefdoms and states (Turchin and Gavrilets, 2009, Gavrilets et al 2010) and empires (Turchin et al. 2013).

I am involved in NIMBioS' collaborative projects on hierarchy and leadership, evolution of institutions, and evolutionary approaches to sustainability. Earlier I co-organized NIMBioS collaborative projects focusing on coalitions and alliances and on modeling social coplexity.

My more recent projects focus on social norms, social institution, beliefs and cognitive processes, inequality.

Speciation and adaptive radiation

I have been developing mathematical foundations for a general theory of speciation. The models I have built predict how different quantitative characteristics of speciation process (e.g., the probability of speciation, the average waiting time to speciation, the average actual duration of speciation, the relative sizes of new sister species, etc.) depend on the rates of mutation and migration, on the population size, on the strength of selection for local adaptation, and on genetics of reproductive isolation (e.g., Gavrilets et al. 1998; 2000; Gavrilets 1999  2000,2003,2005, Gavrilets & Hastings 1996; Gavrilets & Boake 1998, Gavrilets 1996,  Matessi et al. 2001, Gavrilets & Waxman 2002, McPeek & Gavrilets 2006). My book summarizes most of this work. More recently I have worked on models of adaptive radiation (Gavrilets and Vose, 2005, 2009, Gavrilets and Losos 2009, Birand et al 2011) and on models of ecological speciation tailored for particular systems: cichlids, palms, butterflies, snails, fungi, lizards, and sticklebacks (Gavrilets et al. 2007, Gavrilets and Vose 2007, Duenez-Guzman et al. 2009, Sadedine et al. 2009, Giraud et al. 2010, Roeti et al. 2014; see also Fitzpatrick et al. 2008, 2009).

Sexual conflict

Sexual conflict occurs when characteristics that enhance the reproductive success of one sex reduce fitness of the other sex. Numerous examples of sexual conflict resulting from sensory exploitation, polyspermy and the cost of mating are known. The potential for evolution due to such conflict has been evaluated experimentally. I have been developing mathematical foundations of a dynamical theory of evolutionary consequences of sexual conflict. I have used my models to explain: rapid evolution of traits and proteins responsible for fertilization (Gavrilets 2000), the origin of female mate choice (Gavrilets et al. 2001), the effects of sexual conflict on the possibility of speciation (Gavrilets & Waxman 2002, Gavrilets & Hayashi 2005) and 2- and 3-way sexual conflicts (Gavrilets and Hayashi 2006). With Bill Rice and Urban Friberg we have studied sexually antagonistic maternal selection (Miller et al. 2006), maintenance of homosexuality (Gavrilets and Rice 2006, Rice et al. 2012, 2013), sexually antagonistic "zygotic drive" (Rice et al. 2008), and sexually antagonistic grandparental care (Rice et al. 2010).

Holey fitness landscapes

My work (e.g., Gavrilets & Gravner 1997; Gavrilets 1997; Gavrilets 2003, Gavrilets 2004, 2010, Gravner et al. 2007) has lead to understanding that the properties of multi-dimensional fitness landscapes are quite different from those implied in Wright's (1932) metaphor of rugged fitness landscapes. I have been advancing a refined view of fitness landscapes (holey fitness landscapes) focusing on nearly neutral networks of high-fitness genotypes extending throughout the genotype space. These networks provide a way for extensive genetic and phenotypic divergence without the need to cross any fitness valleys. I have shown that nearly neutral networks are a general feature of multidimensional fitness landscapes. I believe this theoretical result is of general and fundamental importance. I have studied the properties of these networks and holey fitness landscapes existing in a number of important population genetic models. See the first chapters of my book for more discussion of fitness landscapes.

Microevolutionary processes and macroevolutionary patterns

I have been developing a mathematical formalism linking microevolutionary processes with macroevolutionary patterns. In a serious of papers, I was able to establish some important relationships across different evolutionary scales (from individuals to populations to species to clades). Examples include projects focusing on:

• the relationships between the rates of mutation and deme extinction and the number of species, their range sizes and the degree of diversification in a metapopulation (Gavrilets et al. 2000),
• the relationships between species-level processes and clade-level patterns with application to the diversification of blastozoan over 300 million years (Gavrilets 1999),
• the waiting time and duration of parapatric speciation as functions of  mutation and migration rates, intensity of selection for local adaptation and genetics of for reproductive isolation (Gavrilets 2000b). 
•    See also a paper attempting to reconcile microevolutionary processes with macroevolutionary patterns (Eldredge et al. 2005) and papers on the dynamics of adaptive radiation mentioned above.

Some other projects

I have also worked with mathematical models aiming to describe/explain:

• the origins of the division of labor, differentiated multicellularity (Gavrilets 2010), and eusociality by manipulation (Gonzalez-Forero and Gavrilets 2013)
• maintenance of genetic variation in natural populations (Zhivotovsky & Gavrilets 1992; Gavrilets 1993; Gavrilets & Hastings 1993; Gavrilets and de Jong 1993; Gavrilets & Hastings 1994)
• dynamics of genetic variation under selection (Gavrilets & Hastings 1994; Gavrilets & Hastings 1994)
• phenotypic plasticity ( Gavrilets & Scheiner 1993a; Gavrilets & Scheiner 1993b; de Jong & Gavrilets 2000) and developmental noise (Gavrilets & Hastings 1994)
• frequency-dependent selection (Gavrilets & Hastings 1995; Waxman and Gavrilets 2005a,b) and coevolution (Gavrilets 1997; Gavrilets & Hastings 1998, Kopp & Gavrilets 2006)
• maternal and parental effects (Gavrilets 1998, Miller et al. 2006, Gavrilets & Rice 2006)
• hybrid zones and clines (Gavrilets 1997a ; Gavrilets 1997b; Gavrilets & Cruzan 1998; Hastings & Gavrilets 1999)
• spatially heterogeneous selection (Gavrilets & Gibson 2002)