Congrats Emily! Great work!

Thanks Bill! 🙂

Thanks Liz! 🙂

10/10 We suggest that the evolution of many other traits, not typically considered key innovations, could affect species diversification in this way.

9/10 These results suggest that the combination of uniquely high evolutionary lability and the ecological versatility of complex teeth drove rapid diversification of cichlids in Lakes Malawi, Victoria, and Barombi Mbo. A new explanation for why these groups diversify so rapidly!

8/10 But having complex teeth is still a benefit. When lineages have complex teeth, they switch between different diets at much faster rates. This ecological versatility is elevated because complex teeth allow transitions through herbivory and omnivory.

7/10 When we fit SSE models, we find lability (greens) consistently increases speciation rate, despite high background rate variation. So, differences in lability explain speciation rate differences within rift lakes AND across habitats – separating out the “rift lake” effect.

6/10 Investigating this with more complex Bayesian models, we find that even within African cichlids, there are differences in lability. Lability is much higher in Lakes Malawi, Victoria, and Barombi Mbo – exceptional adaptive radiations.

5/10 But the distribution of high lability is uneven. This is concentrated within African cichlids (and NOT neotropical cichlids). The prevalence of lability of tooth complex in African cichlids is unique!

4/10 Comparing the effects of complexity and lability, we find it’s lability that increases speciation rates by 5x! So, rapidly gaining and losing tooth complexity has a much stronger effect than complex teeth alone – a new way to think about key innovations.

3/10 Complex teeth (e.g. molars) are a key innovation for mammals and squamates. We find in fishes, they evolve many (>86) times but remain rare (~11% of species), evolving slowly across most of the tree. But in a few groups, the rate is significantly increased – evolutionary lability.

2/10 Key innovations are thought to rarely evolve with massive effects on diversification. Species differ in capacity to evolve new traits; differences in how innovations evolve has been overlooked. This variation could have strong effects if the trait is linked to ecological divergence.