Evolution of social recognition

Animals vary in whether they can recognize familiar individuals. What explains this diversity? Treating individuals differently based on previous experience is clearly useful in some situations, but the cognitive mechanisms required for individual recognition are presumably costly, so social recognition might only evolve in situations where it is especially advantageous.

I use comparative research between closely related species of frogs to understand the evolution of “dear enemy” recognition, which occurs when territorial individuals recognize their neighbors and respond less aggressively to familiar neighbors than to strangers. Frogs are useful taxonomic group for understanding the evolution of social recognition because species vary in whether they recognize the vocalizations of their neighbors and treat them as “dear enemies”. By using this diversity, I am identifying the ecological and social conditions that have favored the evolution of dear enemy recognition in some species, but not others. I also use acoustic analyses and field playback experiments to uncover the communication and cognitive mechanisms that underlie vocal recognition and how these mechanisms have evolved.

Recognition systems and diversity

Individual variation is a needed for individual recognition, and in some situations, individuals may benefit from being recognized by others. This benefit could favor diversity in a population via negative frequency dependent selection, which occurs when individuals with rare phenotypes have greater fitness than those with common phenotypes, because these rare phenotypes make them more recognizable. What role do individual recognition systems play in producing and maintaining diversity in animal signals?

I am investigating this question in northern paper wasps (Polistes fuscatus), which have highly variable color patterns on their faces. These wasps often found nests cooperatively with other individuals and can recognize the faces of their nestmates. In northern populations, such as in New York, individuals are more cooperative and have more variable color patterns. In southern populations, such as Louisiana, individuals are less cooperative and have very little variation in color patterns.

To explore this question, I am comparing cooperative behavior, color pattern diversity, and genomic evidence of selection on cognition across the range. I am also working to identify the genetic basis of these color patters in order to look for signatures of natural selection at the genomic level that could shed light on how this variation is maintained.

A male mimic poison frog (Ranitomeya imitator) transporting a tadpole

Evolution of parental care and mating systems

Poison frogs display some of the most elaborate forms of parental care among frogs, including transporting tadpoles “piggyback” to pools of water and feeding tadpoles unfertilized eggs. They also have a diversity of sex roles of parental care among species: some have male-only care, others female-only care, and a few species have biparental care. What ecological conditions resulted in the evolution of different forms of parental care? How do sex roles in parental care influence the mating system of a species?

I conduct field experiments to study the adaptive value of male and female parental care and to understand how relative parental investment by males and females influences mating systems.