1. Evolution of the miniature spiders
Patu digua, the smallest known spider (0.37 mm long) on the planet belongs to the family of miniature spiders, Symphytognathidae. The informal group of symphytognathoids comprise the families Anapidae, Mysmenidae, Symphytognathidae and Theridiosomatidae. Two recent studies indicated varying placements of these families using a few genomic loci and morphology. I am using two advanced phylogenetic methods: transcriptomes and target capture (covering the ultra-conserved elements (UCEs)) to reconstruct the phylogeny of orbicularian spiders. This study will determine the timeline of speciation events and inter-relationships between the symphytognathoid spiders and with other orb-web weaving spiders.
2. Spiders are becoming 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.
3. Systematics and biogeography of the leucaugine spider genus Orsinome (Araneae, Tetragnathidae)
The tetragnathid spider genus Orsinome is presently recognized by 17 species, mostly known from Asian tropics, many with singular records and restricted distribution. Although a valid genus, its diagnostic characters have remained unedited since over 120 years. Within the exponentially growing spider phylogenies, this genus has a very poor representation in evolutionary studies. I am revising this genus, delimiting its diagnostic characters and describing detailed morphological characters. A dated phylogeny using six genomic loci and morphology will be used to infer the monophyly of this genus, its relationships within the sub-family Leucauginae and other tetragnathids. Using this phylogeny, I will also reconstruct ancestral area to trace the past dispersal and/or vicariance events that have define the present distribution of Orsinome species. This study will improve our understanding about why some arachnid species in a genus have restricted distribution over other widely distributed species.
4. SpiderIndia: let us all document spiders of India
Knowledge about biodiversity does not seep easily from research papers to general public in the age when biodiversity conservation is priority. To alleviate this knowledge gap, along with Vijay Barve, Florida Museum of Natural History, I use social networking and database platforms to document spiders, beginning with India [example: SpiderIndia Facebook group (>8,000 members)].