Researchers at the Francis Crick Institute have uncovered how the evolution of genetic networks generates the vast diversity of developmental patterns seen across species. The study, led by Dr. Zena Hadjivasiliou, head of the Mathematical and Physical Biology Laboratory, and detailed in the journal PRX Life, provides significant insights into the origins of evolutionary innovations.
The research focuses on gene regulatory networks (GRNs), which are complex systems controlling cellular development. Using over 100,000 computer simulations, the team, including mathematician and computer scientist Dr. Harry Booth, modeled the evolutionary paths of these networks. Their findings indicate that while minor genetic modifications can refine existing developmental patterns, the emergence of novel features, such as the eye spots on butterfly wings, requires more substantial changes to the genetic architecture.
Dr. Booth observed that at a large scale, the inherent randomness of evolution diminishes, revealing fundamental properties of these processes. Dr. Hadjivasiliou emphasized the importance of these discoveries for predicting evolutionary outcomes, stating, "Our model makes headway in explaining how small, seemingly unimportant events in evolutionary history can have lasting impacts on the development and diversity of animal forms." This research addresses a long-standing question in evolutionary biology: if the 'tape of life' were replayed, would the same diversity of animal forms emerge?
The simulations suggest that fine-tuning existing patterns requires subtle adjustments to gene interactions, whereas creating entirely new patterns often necessitates significant overhauls, potentially involving multiple simultaneous changes to the network. This aligns with research on butterfly eyespots, where studies suggest these markings evolved through the repurposing of ancestral GRNs that also govern the development of antennae, legs, and wings. Genes such as Distal-less (Dll) and spalt (sal), critical for eyespot development, share regulatory connections with those involved in antennal development, indicating a reuse of ancient genetic machinery.
The Francis Crick Institute's work offers a robust framework for understanding how genetic networks adapt and evolve, providing a glimpse into the predictability of evolutionary pathways. By simulating these complex processes, scientists are gaining a clearer picture of how the fundamental blueprints of life are sculpted over time, leading to the astonishing array of forms and functions observed in the natural world.