“Dispersal-driven” evolution does not require competitive exclusion. As a result, multiple adaptive lineages can cooccur and coexist in a single evolved population. In sum, our work revealed the importance and outcome of the ecological context shaped by ancestors in ALI-colonizing evolution. [5/5]

Compensation for the fitness costs alone does not explain how WS types increase in frequency. We highlighted the motile-sessile regulation. WS mutations elevate c-di-GMP levels, locking cells into a sessile state. The difference in dispersal from the ALI gives an indirect advantage to WS. [4/5]

However, as written in [1/5], there is a paradox. How can WS take over the ancestors despite the disadvantages? We revealed the role of ancestors. Ancestors pre-colonize the niche to provide physical scaffolds where WS can emerge and stably attach, compensating for the WS fitness costs. [3/5]

[bioRxiv link: doi.org/10.1101/2025... ]
P. fluorescens SBW25 has served as model bacteria for niche-colonizing adaptive radiation. Air-liquid-interface(ALI)-colonizing types (Wrinkly Spreaders, WS) are known to thrive very reproducibly from de-novo mutations within ~5 days of static culture. [2/5]