Bone Biochemistry: Ancient and Degraded Proteins
Most of my research uses protein separation and analysis techniques, particularly 'soft-ionization' mass spectrometry, to investigate degradation in modern and ancient tissues ranging from processed foods to those found in archaeological and palaeontological burial environments. The 'soft-ionization' methods we typically use are Matrix Assisted Laser Desorption Ionization (MALDI) for high-throughput peptide mass fingerprinting (PMF) of samples, and Electrospray Ionization (ESI), which we dedicate for more in-depth sequence analysis. It is the 'soft-ionization' that allows for the analysis of large biomolecules without inducing excessive fragmentation prior to analysis and detection in the mass spectrometer, ideal for studying low quantities of ancient and degraded proteins.
Biomolecular Species Identification in Forensics and Archaeology
Despite early research into the survival of non-collagenous bone proteins such as the small mineral-binding protein osteocalcin, most of my research focuses on the dominant bone protein type 1 collagen because of its structural properties making it highly insoluble, resulting in enhanced survival. During my PhD I developed a method of 'fingerprinting' collagen peptides using a limited fractionation method that separated highly conserved collagen peptides from the more variable ones. Once I discovered that collagen fingerprinting could distinguish between the major domesticate animals used in animal husbandry, including the morphologically similar skeletal remains of sheep and goat, we named the technique ZooMS, after 'Zooarchaeology by Mass Spectrometry'. In archaeological applications we typically use the species identifications to investigate likely animal husbanding practises in the past, where my research has mainly focused on early Near Eastern agriculture including work in Cyprus and south-east Turkey on samples >10,000 years old.
Palaeobiodiversity and Vertebrate Evolution
My current research uses high-throughput ZooMS to investigate how vertebrate biodiversity has changed in Britain over the past few million years, focusing on ~20,000 bone fragments excavated from deposits at the back of Pin Hole Cave, Derbyshire (in collaboration with Creswell Crags Heritage Centre and Manchester Museum) dating back approximately 50,000 years. I am also interested in the phylogenetic inferences we can make using protein sequencing, which have included working on ~650,000 year old mammoth remains from Britain, ~3.5 million year old giant camel fossils discovered in the High Arctic, as well as other more enigmatic species such as the dodo.