Dr Weetman graduated in Zoology (BSc) from the University of Newcastle-upon-Tyne and in Ecology (MSc) from The University of Wales, Bangor. His PhD at The University of Liverpool was followed by postdoctoral positions in the Molecular Ecology and Fisheries Genetics Group at the University of Hull. He joined LSTM in 2006 working as a senior PDRA on IVCC and then NIAID-funded projects on the genetic basis of insecticide resistance in the primary malaria mosquito Anopheles gambiae. He was appointed as Reader in 2020.

His research aims primarily to investigate the genes and mutations responsible for insecticide resistance in mosquitoes and phlebotomine sandflies and how these spread among populations. A goal of this work is to identify and apply DNA markers for molecular surveillance of insecticide resistance in control programmes. A second area of research is in questions related to the causes and consequences of vector speciation and population subdivision and how these regulate transfer of adaptive traits of medical importance. He is also broadly interested in the application of molecular techniques to applied ecological questions in vector biology. He coordinates the Vector Research Support group (VRS), which provides molecular and biochemical collaboration, training and services to students, visiting scientists and for control trials.