Wasp populations that recognize faces cooperate more, and may be smarter than wasp populations that are not capable of face recognition

Amazing stuff! Apparently, these distinguishing phenomena developed/evolved only a few hundred miles apart. 

In biological evolution, geography ca be destiny.

"... Furthermore, genomic sequencing revealed that populations of wasps that recognized each other – and cooperated more – showed recent adaptations (positive selection) in areas of the genome associated with cognitive abilities such as learning, memory and vision. ...
Observing nesting behaviors in the spring when females established nests, ...  found that southern queens mostly remained solitary and established their own nests, but in the north, three or four females would inhabit a nest, with one taking over the role of queen and laying most of the eggs, and the others operating more like workers, engaged more in foraging.

While individuals from northern and southern populations are of the same species, they look very different. Southern paper wasps tend to have nearly identical red color patterns on their faces. The northern ones have distinctive black and yellow patterns. ...
Wasps from the northern population were aggressive to strangers, but much less so to the wasp they had previously met two days earlier. “Individuals in the southern population treat everyone the same,”  ..."

From the highlights and abstract:

"Highlights

• Cooperation and signal diversity covary across the geographic range of a paper wasp

• The ability to recognize individuals is related to cooperation and signal diversity

• Individual recognition stabilizes social groups

• Selection on social cognition genes is stronger in more cooperative populations

Summary

The ability to recognize others is a frequent assumption of models of the evolution of cooperation. At the same time, cooperative behavior has been proposed as a selective agent favoring the evolution of individual recognition abilities. Although theory predicts that recognition and cooperation may co-evolve, data linking recognition abilities and cooperative behavior with evidence of selection are elusive. Here, we provide evidence of a selective link between individual recognition and cooperation in the paper wasp Polistes fuscatus through a combination of clinal, common garden, and population genomics analyses. We identified latitudinal clines in both rates of cooperative nesting and color pattern diversity, consistent with a selective link between recognition and cooperation. In behavioral experiments, we replicated previous results demonstrating individual recognition in cooperative and phenotypically diverse P. fuscatus from New York. In contrast, wasps from a less cooperative and phenotypically uniform Louisiana population showed no evidence of individual recognition. In a common garden experiment, groups of wasps from northern populations formed more stable and individually biased associations, indicating that recognition facilitates group stability. The strength of recent positive selection on cognition-associated loci likely to mediate individual recognition is substantially greater in northern compared with southern P. fuscatus populations. Collectively, these data suggest that individual recognition and cooperative nesting behavior have co-evolved in P. fuscatus because recognition helps stabilize social groups. This work provides evidence of a specific cognitive phenotype under selection because of social interactions, supporting the idea that social behavior can be a key driver of cognitive evolution."

Wasps that recognize faces cooperate more, and may be smarter | Cornell Chronicle Social interactions may well make animals smarter and more diverse, a new study of paper wasps suggests.

Evidence for a selective link between cooperation and individual recognition (no public access)

Graphical abstract

Paper wasps from a northern population in Ithaca have diverse black and yellow color patterns on their faces and are able to recognize individuals.

Paper wasps from a southern population in Louisiana have reddish and more uniform faces and behave indiscriminately towards each other.