These brilliant scientists, led by Canadian Dr. Bob Week, have made a truly historic proposal. They are changing the way we think about host-microbiome dynamics. Their contribution to that effort just published in Nature Ecology and Evolution. They want to broaden existing evolutionary theories to account for dynamic interactions between host organisms and the microorganisms they carry with them. This novel TCN hopes to advance a conceptual, theoretical and methodological framework that puts host-microbiome biology at the forefront of evolutionary biology scholarship and discovery.
The research team hopes that their work can broaden research about evolution by including microbiomes as an important influence on evolutionary processes. They seek to remedy this gap. We outline here their first steps toward a general understanding of how host-associated microbes co-evolve with their hosts. Through the lens of human evolution, they want to dive deep into that complex host-microbiome relationship. Ultimately, this research will make evolutionary biology a more welcoming and equitable space.
The Role of Niche Construction
Their studies examine cultural niche construction. This theory of niche construction highlights the myriad ways in which organisms directly shape their environments, thereby influencing the occurrence and abundance of microbial life. Dr. Week likens this process to agriculture. Time and attention—just like arable land and animal husbandry—need to be cultivated in order to truly flourish. He states:
“Niche construction is comparable to farming, where a farmer grows crops and livestock to ensure the availability of food.” – Dr. Bob Week
In this sense, hosts are dynamic participants, designing their environments to create conditions more favorable to beneficial microbes. This impact can reverberate for the rest of their lives, and even for generations to come. Past→present dynamic This dynamic is fundamental for understanding how microbiomes foster the evolutionary success of their hosts.
As Bohannan, a fellow researcher on this study, explains, that’s a big change. Most evolutionary biologists have only recently begun to embrace the profound lesson for evolution taught by microbiomes, and prevailing paradigms still understand this influence scope as an “extended inheritance phenomenon.” He explains:
“Currently most biologists consider the evolutionary influence of the microbiome as a kind of extended inheritance phenomenon, for which there are already various theoretical frameworks available in evolutionary biology.” – Bohannan
This recognition points to the need for alternative theoretical paradigms that can more accurately account for the complexities of host-microbiome interactions.
Expanding Theoretical Frameworks
The publication outlines four broad theoretical frameworks that are particularly promising for pushing the field of host-microbiome evolution further. These frameworks can provide a jumping off point for deepening our understanding of how microbiomes shape host evolution. Prof. Schulenburg, who is actively involved in the Kiel Life Science (KLS) research area, emphasizes that collaboration with empirical researchers is vital for refining these frameworks:
“In order to better capture the biological diversity of these systems and enable experimental testing, the frameworks we have now presented should be carefully expanded in close collaboration with colleagues working empirically.” – Prof. Schulenburg
It’s through frames like these that our theoretical understanding deepens. They do create actionable paths for future research toward experimental validation. Together these papers connote a promise to combine hard numbers and sophisticated modeling with the liberal arts of evolutionary theory.
Implications for Future Research
This research has major practical and policy implications, far beyond mere intellectual debate. It challenges us to re-think how we build and use evolutionary theories. The deep and dynamic interconnectedness of hosts and their microbiomes indicates that future host-microbe interaction studies need to account for these relationships when studying evolutionary processes.
Collectively, these results underscore the idea that host-associated microbes do not always adhere to classical Mendelian patterns of inheritance. These microbes can be obtained from other environmental sources, not exclusively vertically from parent to offspring. This fundamentally undermines our understanding about how traits are passed on from generation to generation and even across species. It calls for a deeper understanding of evolutionary theory.