Jos Kramer

About Me

I am fascinated by how social life evolves and the hidden ecological forces that shape it. During my PhD, I studied social interactions in insect families, exploring the transition from solitary to social life. More recently, my focus shifted to the microbial world, where I investigated cooperation, conflict, and predation among microbes, and how these interactions drive community dynamics and evolution. Currently, I lead an ERC-funded research group that explores how these two worlds – animal sociality and microbial ecology – intersect.

Our Research: Animal Social Life & Animal-Microbe Interactions

Social behavior among animals is one of the most fascinating and influential aspects of life on Earth. From family groups to complex societies, social behaviors shape life-histories and drive biological diversity and complexity. Yet, one important ecological factor behind social life remains poorly understood: microbes. These microscopic organisms are present almost everywhere, and while they were long seen as pathogenic threats to social life, research now shows that they can also benefit social animals—helping with nutrition, communication, and even collective defenses. However, most studies focus on a few highly social flagship species and often consider microbes in broad terms, leaving key questions unanswered: How do microbes influence the origins of social life? And how do social behaviors help animals control their relationships with beneficial and harmful microbes?

To tackle these questions, we combine behavioral ecology, microbiology, and metagenomics to study social behaviors and animal-microbe interactions in Nicrophorus burying beetles. These beetles offer a unique window into the early evolution of social life: they raise their young on small animal carcasses, and their parental behaviors are essential for managing beneficial symbionts and harmful environmental microbes growing on their breeding resource. Our current work seeks to:

1. uncover how social behaviors and microbial interactions influence each other,
2. explore how microbes shaped the early evolution of social life, and
3. investigate the co-evolution of animal sociality and symbiosis with microbes.

Through our research, we want to shed light on the social control of microbes and the ecological forces shaping animal societies. We believe that revealing the hidden microbial dimension of animal social life will help us understand not only how animal societies arose, but also how their complexity is intertwined with the smallest organisms on our planet.