Harvard DEPARTMENT OF ORGANISMIC AND EVOLUTIONARY BIOLOGY
Hanken slide

HANKEN LABORATORY
EVOLUTION: MORPHOLOGY, DEVELOPMENT AND SYSTEMATICS

Here are a few examples of research in the lab:

Pachytriton
Pachytriton labiatus
Systematics of Chinese salamanders

Based on multiple independent evidences, Yunke Wu's doctoral study was aimed at understanding the phylogeny of Pachytriton, Paramesotriton and Cynops, evaluating taxonomical relationships and validity of controversial taxa, and answering questions like how genetic differentiation has been driven by geological or historical factors. This long-term research focused on the biodiversity of Asian newts, the evolution of morphological characters associated with adaptation and the biogeography of East Asian amphibians.

Pachytriton, Paramesotriton and Cynops are part of the Salamandridae, a speciose urodele family, which mostly occur at the Holarctic region with its diversity center in temperate Europe and Asia. They are collectively called the modern Asian newts, and are monophyletic supported by mitochondrial DNA. Nevertheless, complicated morphological homoplasies and possible long branch attraction of molecular sequences obscure phylogenetic relationships among and within these three genera. Descriptions of newly discovered species and reports of unusual phenotypes further increase complexity of this clade. Meanwhile, the three genera are widely distributed in East Asia, especially in southeastern China, providing excellent materials to understand historical factors that have influenced animal population structures in this area, a vast region yet with little knowledge on biogeographic patterns.

Pachytriton
Pachytriton brevipes

Africa
Phrynobatrachus pakenhami

Evolution of African frogs

Breda Zimkus is currently completing post-doctoral research on the evolution of rocket frogs (Anura: Ptychadenidae). Breda completed her dissertation research in the Hanken Lab, focusing on the evolution of puddle frogs (Anura: Phrynobatrachidae), a group of approximately 80 species distributed across sub-Saharan Africa within diverse terrestrial habitats. Breda is now focused on frogs of the genus Ptychadena, which widely distributed across sub-Saharan Africa, Nilotic Egypt, Madagascar, Seychelles Islands, and the Mascarene Islands and currently include approximately 50 species. Using molecular and morphological data collected from museum specimens and specimens collected during her fieldwork in Malawi, Ethiopia, and Tanzania, Breda is constructing a phylogeny of this group to resolve its taxonomy, as well as investigate patternsof continental speciation.

Breda Breda
Africa
Phrynobatrachus natalensis
   


 
Copyright 1996 James Hanken