Color Polymorphism is a Driver of Diversification in the Lizard Family Lacertidae

Area of Science:

• Evolutionary Biology
• Zoology
• Genetics

Background:

• Color polymorphism, defined as multiple heritable color phenotypes within a population, is a widespread form of intraspecific diversity.
• This trait is theorized to promote speciation and elevate diversification rates, making polymorphic lineages ideal for macroevolutionary studies.
• The lizard family Lacertidae exhibits extensive color polymorphism, offering a valuable model system to investigate its evolutionary impact.

Purpose of the Study:

• To reconstruct the evolutionary history of color polymorphism in the Lacertidae family.
• To test the hypothesis that color polymorphism acts as a driver of diversification within this lizard group.
• To investigate the origins and evolutionary dynamics of color polymorphism in Lacertidae.

Main Methods:

• Construction of a comprehensive, species-level phylogeny for the Lacertidae family.
• Phylogenetic analyses incorporating multiple phylogenies to account for uncertainty.
• Simulation studies to model trait-dependent diversification and evolutionary transitions.

Main Results:

• Color polymorphism in Lacertidae originated approximately 111 million years ago within the Lacertini tribe.
• The trait has likely evolved infrequently but has been lost at a higher rate.
• Transitions to color polymorphism are significantly associated with increased net diversification rates.

Conclusions:

• Color polymorphism is an ancient trait in Lacertidae lizards.
• The evolution and maintenance of color polymorphism are strongly linked to elevated diversification rates.
• Empirical findings support the long-standing theory of color polymorphism as a driver of speciation and macroevolution.