How did spiders become smaller?: tracing the palp size reduction and its loss

In female spiders, the second pair of appendages, pedipalps serves as a sensory organ and in males they are modified as secondary reproductive organs. Interestingly, females of miniature spiders (Anapidae and Symphytognathidae) have reduced palp while many of their species have completely lost these palps. I am exploring the evolution of this palp size reduction and complete loss.

A comparison of the evolutionary relationships that I recover from above study and a total evidence analysis using morphology and molecular data provide a good idea about resolution. Here, optimization of palpal characters on the resulting tree topology will date the evolution of palp, its reduction and loss or secondary gain in other spiders. A previous claim that ‘miniaturization’ is not convergence can also be tested using advanced techniques. This study will provide a greater understanding about character evolution in cryptic arthropods.