Bonus: look at these beautiful colors and patterns!

We also worked with the local Phyllodactylus geckos, aiming to compare them with the populations found in the mainland from an ecomorphological perspective. Overall a great experience with a great team. More on the evolution of these two insular lizard lineages soon!

Both variables contribute to bone strength but cannot be simultaneously maximized. We found that island and mainland species tend to use opposite strategies, possibly due to life history differences.

Low-density high-hollowness bones vs high density low-hollowness bones in anoles!

academic.oup.com/evolut/artic...

Among other things, these results illustrate how looking at allometric patterns of performance dimorphism directly (i.e. testing Rensch's Rule patterns on performance traits) can complement observations based on the traditional Rensch's Rule patterns of body size. Many more details in the paper!

But, consistent with our expectation of a strong sexual selection regime on islands, relative bite force dimorphism is higher in island species when compared to mainland ones, independently of size. This difference is only partly explained by relative head dimorphism being higher in island species.

Testing Rensch's Rule in bite force showed us that SSD actually explains performance dimorphism very well: on average, males from large species don't get disproportionate performance benefits by getting larger.

To reconnect patterns of SSD with performance dimorphism we tested Rensch's Rule in bite force performance. Yes! Rensch's Rule is not only a pattern that involves SSD, you can read more about that here:
www.biorxiv.org/content/10.1...

Anoles follow Rensch's Rule, but how does it relate to performance dimorphism?

However, the nature of the relationship between size and performance is rarely directly measured. This implies that an observed Rensch's Rule pattern in body size is actually compatible with different patterns of performance dimorphism.

Rensch's Rule, a famous macroevolutionary pattern, tells us that male-biased SSD increases with species size. A common hypothesis for the emergence of the pattern involves sexual selection: higher dimorphism is driven by males evolving large sizes in order to enhance combat performance.