Micrognathozoa
Micrognathozoa are some of the smallest animals in the world reaching a maximum adult size of 150µm. They are the most recent phylum of animals to be discovered and was first reported from a freshwater spring in Greenland in 2000. Despite their tiny size, they have some of the most complex jaws in the animal kingdom composed of over a dozen moving parts. Apart from Greenland, they are only known from two other places: the Pyrenees of Catalonia, and the Subantarctic Crozet Islands. Using single cell transcriptome techniques, advanced microscopy, and machine learning, we have just described the second species of the phylum Limnognathia desmeti. But how did these animals get this crazy, disjunct distribution?
Meiofaunal Genomics
Meiofauna are a size class of animals that fall through a ~500µm mesh but are caught on a ~45µm mesh. The majority of phyla have meiofaunal representatives and some phyla are exclusively meiofaunal. I am studying the genomes of different meiofaunal groups across the Animal Tree of Life trying to learn about how and why they got so small.
Phylogenetics
I am broadly interested in the phylogenetics of various invertebrates, mostly focused on arachnids and onychophorans. Using molecular data from single locus Sanger sequencing to multi-locus genomic scale sequencing, I try to reconstruct the relationships of enigmatic invertebrate groups and use the resulting phylogenies to discover new species, infer their evolutionary histories, and uncover their biogeographic patterns.
Onychophoran Genomics
Onychophora (velvet worms or peripatus) are the only exclusively terrestrial phylum of animals. They are many-legged, soft bodied worms that live in moist habitats in the tropics and the southern hemisphere. They are particularly famous for their distinctive mode of prey capture which involves shooting a slimy glue from modified appendages to entangle prey. They are also noted for their remarkable diversity of reproductive strategies that range from oviparity, through ovoviviparity, to placental viviparity. Onychophora hold a pivotal place in metazoan phylogenetics as the putative sister group to Arthropoda. To rectify the near complete lack of genomic data for the phylum, I have assembled the genome of Epiperipatus broadwayi. This genome is the highest quality onychophoran genome to date and is the only annotated genome for this phylum. It will be integral in understanding the phylogenetics, biogeography, and evolution of reproductive strategies in this unique lineage and will hopefully serve as a genomic toolkit to spur further research into this little-understood group.
Ultra-conserved Elements
Ultra-conserved elements or UCEs are a class of molecular marker that allows for target enrichment across species with hundreds of millions of years of divergence. They have also been suggested to be better than phylotranscriptomics at resolving rapid radiations. Additionally, the molecular methods used for library preparation do not require fresh tissues, a limiting factor for sequencing transcriptomes. The relationships within Neopatida, a clade of Neotropical peripatid onychophorans, have remained unresolved probably due to rapid cladogenesis in the group, particularly across the Caribbean Islands. To tackle the complex evolutionary and taxonomic history in this group, I designed the first UCE probeset for the phylum Onychophora using newly sequenced genomes and uncovered a new Neotropical lineage that challenges our long-held understanding of onychophoran biogeography.
Ricinulei
Ricinulei (hooded tick spiders), is a small order of arachnids whose affinities are contentious. However, they are frequently recovered at sister-group to Xiphosura, the horseshoe crabs. All 100 or so species are in three genera: Cryptocellus from South America, Pseudocellus from North America, and Ricinoides from Africa. The three molecular phylogenetic studies of this group have revealed conflicting relationships among these genera and suffered from the trade-off between numbers of loci and taxon sampling. With new material from Cuba, Mexico, and the Andes, I reconstructed the first UCE, and the most comprehensive phylogenomic phylogeny for the group to understand the relationships among the major clades within Ricinulei.
image: Gonzalo Giribet
