A morphological basis for path-dependent evolution of visual systems. (https://pubmed.ncbi.nlm.nih.gov/38422123/)

These scientists studied how evolution can be influenced by past events in a way that makes it hard to predict what will happen next. They wanted to see if they could find examples of this in nature, not just in a lab.

They found that chitons, which are small marine animals with shells made of plates, evolved two different types of visual systems. The type of visual system a chiton lineage could evolve depended on how many openings it had in its shell plates for sensory nerves.

If a chiton had more openings, it evolved visual systems with thousands of eyespots. If it had fewer openings, it evolved visual systems with hundreds of shell eyes. This shows that the evolution of these visual systems was influenced by past events and was not entirely predictable.

So, the scientists discovered that the way chitons evolved their visual systems was both determined by their past and also a bit random, making it a complex and interesting process to study.

Varney RM., Speiser DI., Cannon JT., Aguilar MA., Eernisse DJ., Oakley TH. A morphological basis for path-dependent evolution of visual systems. Science. 2024 Mar;383(6686):983-987. doi: 10.1126/science.adg2689. Epub 2024 Feb 29.